Journal articles on the topic 'Groundwater quality processes and contaminated land assessment'

Abstract In Bantul, Southern Yogyakarta, groundwater is the main source of domestic water needs. Therefore, knowing the hydrogeochemistry of groundwater is crucial in order to manage a sustainable groundwater resource. To characterize the compelling geochemical processes that control the groundwater chemistry, further hydrogeochemical examinations were directed in the area. Thirty groundwater samples were collected from shallow dug wells during the early dry season (April 2021). Sampling procedures and chemical analysis were carried out as per standard methods with secondary data obtained in 2006. The geochemical evaluations were depicted using several graphical plots dependent on the ionic constituents, hydrochemical facies, and controlling factors of groundwater quality. Two major hydrochemical facies were identified: alkaline-earth water with higher alkali; bicarbonate predominated (62%) and alkaline-earth water; bicarbonate predominated (32%). Weathering of silicate minerals occurs in 70% of recent samples and predominantly regulates major ion chemistry such as calcium, magnesium, sodium, and potassium. Chloro-alkaline indices 1,2 values signify that there are two potential rock-water interaction processes in the study region, namely the ion exchange and reverse ion exchange. Concentrations of nitrate, sulfate, and chloride indicate that the water chemistry has not been heavily contaminated by the land use in the area and is still mainly controlled by geogenic processes rather than anthropogenic activities.

Nitrates are one of the most common groundwater contaminants and they come from different sources. The paper presents a study of groundwater quality at Varaždin wellfield in the north part of Croatia. The nitrate concentration at this location has been above the maximum allowed concentration for several decades, which has made the opening of new wellfields costly. Based on the previously developed groundwater flow model, a model that covers the narrow area of the wellfield is developed. The influential zone of the observed wellfield in working conditions is determined. Based on the developed model, the sources of nitrate pollution are located, which can be generally divided into non-point and point sources. Considering the time of groundwater retention in the horizontal flow, it is concluded that the water protection zones are marked following the applicable ordinance. Based on the developed groundwater flow model at the observed wellfield, a simulation of nitrate pollution propagation by advection and dispersion processes is performed. The simulation results point out the location of the poultry landfill as the largest source of nitrate pollution. However, poultry farms, which are located in the influence area of the wellfield, also contribute significantly to the nitrate concentration at the wellfield.

Thriving of the society in Zhengzhou city and development of its economy needs scientific and practical solutions of two main problems; natural water shortage and pollution. It is essential to assess the groundwater quality in order to confirm public safety in Zhengzhou and to reduce contamination in there. Fuzzy Synthetic evaluation was applied to delineate the extent of groundwater contamination in Zhengzhou. Assessment of shallow groundwater results concluded that the first three grades of Chinese water quality standards are 91%, whereas the fourth and fifth grades constitute 9% of it. For the deep water quality, the first two grades are 94% and 6%. It is deduced that part of the shallow groundwater quality is effectively contaminated. Contamination disappears going downward into the deep water. Cluster analysis show exactly same deduction. Fuzzy synthetic evaluation results (using Geographic Information System) were employed to assess the groundwater flow direction around the surveyed wells. It is concluded that infiltration of upstream industrial groundwater is probable into the deep confined groundwater

Abstract. Climate and land use change (global change) impacts on groundwater systems cannot be studied in isolation, as various and complex interactions in the hydrological cycle take part. Land-use and land-cover (LULC) changes have a great impact on the water cycle and contaminant production and transport. Groundwater flow and storage are changing in response not only to climatic changes but also to human impacts on land uses and demands (global change). Changes in future climate and land uses will alter the hydrologic cycles and subsequently impact the quantity and quality of regional water systems. Predicting the behavior of recharge and discharge conditions under future climatic and land use changes is essential for integrated water management and adaptation. In the Mancha Oriental system in Spain, in the last decades the transformation from dry to irrigated lands has led to a significant drop of the groundwater table in one of the largest groundwater bodies in Spain, with the consequent effect on stream-aquifer interaction in the connected Jucar River. Streamflow depletion is compromising the related ecosystems and the supply to the downstream demands, provoking a complex management issue. The intense use of fertilizer in agriculture is also leading to locally high groundwater nitrate concentrations. Understanding the spatial and temporal distribution of water availability and water quality is essential for a proper management of the system. In this paper we analyze the potential impact of climate and land use change in the system by using an integrated modelling framework consisting of the sequentially coupling of a watershed agriculturally-based hydrological model (SWAT) with the ground-water model MODFLOW and mass-transport model MT3D. SWAT model outputs (mainly groundwater recharge and pumping, considering new irrigation needs under changing ET and precipitation) are used as MODFLOW inputs to simulate changes in groundwater flow and storage and impacts on stream-aquifer interaction. SWAT and MODFLOW outputs (nitrate loads from SWAT, groundwater velocity field from MODFLOW) are used as MT3D inputs for assessing the fate and transport of nitrate leached from the topsoil. Results on river discharge, crop yields, groundwater levels and groundwater nitrate concentrations obtained from simulation fit well to the observed values. Three climate change scenarios have been considered, corresponding to 3 different GCMs for emission scenario A1B, covering the control period, and short, medium and long-term future periods. A multi-temporal analysis of LULC change was carried out, helped by the study of historical trends by remote sensing images and key driving forces to explain LULC transitions. Markov chains and European scenarios and projections have been used to quantify trends in the future. The cellular automata technique was applied for stochastic modeling future LULC maps. The results show the sensitivity of groundwater quantity and quality (nitrate pollution) to climate and land use changes, and the need to implement adaptation measures in order to prevent further groundwater level declines and increasing nitrate concentrations. The sequential modelling chain has been proved to be a valuable assessment and management tool for supporting the development of sustainable management strategies.

The aim of this study was to evaluate the quality and hydrochemical characteristics of urban groundwater in Urmia City, northwest of Iran. In order, 59 groundwater samples were collected and analyzed for various anions and cations. Result shows that, mineral weathering, ion exchange and anthropogenic activity are the main hydrochemical processes controlling urban groundwater chemistry. The evaluation of groundwater geochemistry in the flow path beneath the urban area shows that, due to land use changes, the hydrochemical change occurs predominantly in electrical conductivity (EC), Cl− and NO3–. The EC is increased in the direction of groundwater flow and in the last decade in industrial areas. According to the groundwater quality index values, most of the samples fit into the good quality class and samples with poor quality are located in the old residential, parks and agricultural areas of the city. The calculation of the irrigation water quality indices (Na%, sodium adsorption ratio, permeability index, residual sodium carbonate), and industrial water quality indices (Ryznar stability index, Langelier saturation index, Larson–Skold, Puckorius scaling index) indicated that the quality of water for irrigation purposes could be classified in the excellent to permissible categories. However, as for the industrial uses, the results also revealed that most of the samples could be classified in the aggressive and very aggressive categories.

Groundwater quality is substantial for social and economic activities in Greece since the majority of the cultivated land is irrigated by water abstracted from aquifers, via a large number of wells and boreholes. The main sources of groundwater pollution are the fertilizers used in agriculture, and the disposal of untreated wastewater from domestic and industrial use. The plain part of Almopia basin, North Greece, is a rural area with intense agricultural activities (including livestock), without significant industrial activity or urban centers. Mild touristic activity has been developed during the last decades in the area of Loutraki, due to the exploitation of the local geothermal field (Pozar springs) for balneotherapy. The aim of this paper is to evaluate the groundwater quality using conventional statistical methods, as well as to employ multivariate statistical methods (factor analysis, cluster analysis) in order to identify the main hydrogeological processes or human activities that affect and determine the water character. The area was selected because of the extended cultivating activities that take place within its boundaries and the availability of adequate data. According to the results of the implemented research, the groundwater samples are of good quality, whereas the chemical composition is mainly formed by the interaction between the water and the geological formations.

The continuous intake of contaminated drinking water causes serious issues for human health. In order to estimate the suitability of groundwater for drinking and irrigation, and also conduct human risk assessments of various groups of people, a total of 43 sample locations in the semi-arid southern part of India were selected based on population density, and we collected and analyzed groundwater from the locations for major anions and cations. The present study’s novelty is integrating hydrochemical analysis with the entropy water quality index (EWQI), nitrate pollution index (NPI) and human health risk assessment. The results of the EWQI revealed that 44.19% of the sample locations need to be treated before consumption. About 37.20% of the study region has a high concentration of nitrate in the groundwater. NPI revealed that 41.86% of the samples had moderate or significant pollution levels. The non-carcinogenic risk evaluation showed that 6–12-year-old children are at a higher risk than teenagers, adults and elderly people in the study area. The natural sources of nitrate and other contamination of groundwater are rock–water interaction, weathering of rock, dissolution of carbonate minerals and evaporation processes, and the anthropogenic sources are the decomposition of organic substances in dumping yards, uncovered septic tanks and human and animal waste. The results suggest taking mitigation measures to reduce the contamination and improve the sustainable planning of groundwater management.

Landfills are one of the groundwater pollution sources in Rwanda. Physical and chemical analyses of water samples were carried out to assure the magnitude of Nduba Landfill on ground water quality. Laboratory tests were conducted to get the results which helped us to study the assessment of leachate effect and to propose mitigation measures of Nduba landfill. The results showed that most of water were contaminated, where concentration of most physical and chemical parameters were above acceptable standard levels required by local and international standards for potable. The analytical results of leachates samples (Cu: 38.5 mg/L, Mn: 13.075mg/l, Zn:15mg/l, TP:4525mg/l, pH:8.52µS/cm, COD:7100mg/l, BOD:182.1mg/l, TN:5mg/l and Fe: 43.025 mg/L) showed that heavy metals are leached out from the MSW. The analytical results of groundwater from the wells located in the vicinity of Nduba landfill site (Cu: 2 mg/L, Zn:3.5-5.5mg/l, SO42-: 250-275mg/l, NO3-: 55-67.5mg/l,NH4+:1.5-2.25mg/l, COD: 39-53.4mg/l, Fe: 1.75-4.25 mg/L, Turbidity: 4.03-4.32NTU, pH:5.31-5.73µS/cm, Temperature: 21°C and BOD:20.7-21.6mg/l) compared to the World Health Organization standard (Cu:0.1mg/L,Fe:0.3mg/L,Zn:5mg/l,SO42-:200mg/l,NO3-:50mg/l,NH4+:1.5mg/l,Turbidity:<5.0 NTU and pH:6.5-9.2µS/cm) revealed that groundwater from the wells located in the vicinity of Nduba landfill site requires further physical chemical treatment to ensure their suitability for human consumption as the levels of some water quality parameters exceeded the EPA guidelines for drinking water. Designing a sanitary landfill was recommended to avoid effects of leachate on environment.

Natural and anthropogenic causes jointly lead to land degradation and eventually to desertification, which occurs in arid, semiarid, and dry subhumid areas. Furthermore, extended drought periods may cause soil exposure and erosion, land degradation and, finally, desertification. Several climatic, geological, hydrological, physiographic, biological, as well as human factors contribute to desertification. This paper presents a methodological procedure for the quantitative classification of desertification severity over a watershed with degraded groundwater resources. It starts with drought assessment using Standardized Precipitation Index (SPI), based on gridded satellite-based precipitation data (taken from the CHIRPS database), then erosion potential is assessed through modeling. The groundwater levels are estimated with the use of a simulation model and the groundwater quality components of desertification, based on scattered data, are interpolated with the use of geostatistical tools. Finally, the combination of the desertification severity components leads to the final mapping of desertification severity classification.

Despite being a finite resource, both the quality and quantity of groundwater are under tremendous pressure due to rapid global changes, viz. population growth, land-use/land-cover changes (LULC), and climate change. The 6th Sustainable Development Goal (SDG) aims to “Ensure availability and sustainable management of water and sanitation for all”. One of the most significant dimensions of the SDG agenda is the emphasis on data and governance. However, the lack of good governance coupled with good observed data cannot ensure the achievement of SDG6. Therefore, this study strives to evaluate water quality status and hydrochemical processes governing it in the data-scarce Mokopane area of South Africa. Groundwater is the main source of fresh water supply for domestic usage, intensive agriculture, and mining activities in Mokopane. In this study, hydrogeochemical analysis of groundwater samples was employed to calculate the water quality index (WQI) and evaluate factors governing water quality evolution in the study area. Statistical and spatial analysis techniques were carried out to divide sampling sites into clusters and delineate principal factors responsible for determining water quality of the sampled groundwater. Results suggest that most of the physico-chemical parameters are within permissible limits for drinking water set by the World Health Organization (WHO), except for high fluoride in some samples. Na-HCO3 is the most abundant water type followed by Mg-HCO3, which indicates dominance of Na+, Mg2+, and HCO3±. Rock-water interaction is the prime factor responsible for fluoride enrichment in water. The alkaline nature of groundwater favors the release of exchangeable F− from minerals like muscovite. The WQI suggests that 80% of water samples fall into the good and excellent categories. Poor management of untreated domestic sewage and agricultural runoff is a main factor for the bad/very bad categories of water samples. As the area lacks any credible scientific/government work to report water quality and its management aspects, the findings of this study will definitely help both scientific communities and policy makers to do what is needed for sustainable water resource management in a timely manner.

Groundwater is the major water resource for the agricultural development of the Guanzhong Basin, China. In this study, a total of 97 groundwater samples (51 from the North Bank of the Wei River (NBWR) and 46 from the South Bank of the Wei River (SBWR)) were collected from the central-western Guanzhong Basin. The aim of this study was to investigate the hydrogeochemical characteristics of the basin and to determine the suitability of shallow groundwater for irrigation. The groundwater of the entire study area is alkaline. The groundwater of the SBWR is fresh water, and the NBWR groundwater is either freshwater or brackish water. The average concentration of ions (except for Ca2+) in SBWR samples is lower than in NBWR samples. HCO3− is dominant in the groundwater of the study area. Ca2+ is dominant in the SBWR while Na+ is dominant in the NBWR. The SBWR groundwater is mainly of the HCO3-Ca·Mg type, and has undergone the main hydrogeochemical processes of rock weathering-leaching. The hydrochemical facies of the majority of the NBWR groundwater samples are the HCO3-Na type with several minor hydrochemical facies of the HCO3-Ca·Mg, SO4·Cl-Na, and SO4·Cl-Ca·Mg types. Its chemistry is mainly controlled by rock weathering, cation exchange, and evaporation. Salinity hazard, sodium percentage, sodium adsorption ratio, residual sodium carbonate, magnesium hazard, permeability index, Kelley’s ratio, potential salinity, synthetic harmful coefficient, and irrigation coefficient were assessed to evaluate the irrigation quality of groundwater. The results of the comprehensive consideration of these indicators indicate that the percentage of NBWR water samples suitable for irrigation purposes ranges between 15.7% and 100% at an average level of 56.7%. Of the SBWR water samples suitable for irrigation, the percentage ranges from 78.3% to 100% with an average of 91.8%. Land irrigated with such water will not be exposed to any alkali hazard, but will suffer from a salinity hazard, which is more severe in the NBWR. Thus, most of the water in the NBWR can be used for soils with good drainage conditions which control salinity.

Strategies of groundwater protection in agricultural dominated areas are mainly based on a general reduction of the input of nutrients like nitrate. However, preventive measures in different parts of the catchment may provide very different effects on raw water quality. Exemplified on the case study ‘Liedern’ (BEW GmbH Bocholt, Germany) it is shown that hydrogeochemical processes along the flow path and in the well strongly affect the results of agricultural measures in terms of modality and efficiency. Thus, a reduction of fertilization in the vicinity of the well gallery leads to a decrease of nitrate concentration in the raw water. Whereas agricultural measures in the eastern part of the catchment do not influence nitrate, but cause a reduction of the iron concentration and rate of incrustation in the wells after 18 years. In this study we present a management tool that enables assessment of future trends in raw water quality. The tool is based on a reactive transport model which considers land use dynamics as an instrument to influence groundwater/raw water quality. A thermodynamic equilibrium approach is applied for modelling hydrogeochemical processes between aqueous, solid and gaseous phases. Kinetically controlled reactions like the microbial degradation of organic carbon are expressed by multiplicative Michaelis–Menten equations.

Recognition of sustainability issues around water resource consumption is gaining traction under global warming and land utilization complexities. These concerns increase the challenge of gaining an appropriate comprehension of the anthropogenic activities and natural processes, as well as how they influence the quality of surface water and groundwater systems. The characteristics of water resources cause difficulties in the comprehensive assessment regarding the source types, pathways, and pollutants behaviors. As the behavior and prediction of widely known contaminants in the water resources remain challenging, some new issues have developed regarding heavy metal pollutants. The main aim of this review is to focus on certain essential pollutants’ discharge from anthropogenic activities categorized based on land-use sectors such as industrial applications (solid/liquid wastes, chemical compounds, mining activities, spills, and leaks), urban development (municipal wastes, land use practices, and others), and agricultural practices (pesticides and fertilizers). Further, important pollutants released from natural processes classified based on climate change, natural disasters, geological factors, soil/matrix, and hyporheic exchange in the aquatic environment, are also discussed. Moreover, this study addresses the major inorganic substances (nitrogen, fluoride, and heavy metals concentrations). This study also emphasizes the necessity of transdisciplinary research and cross-border communication to achieve sustainable water quality using sound science, adaptable legislation, and management systems.

Groundwater is a precious source of fresh water and a major component of the entire water supply. Both water quality and quantity could be satisfied by evaluating the groundwater potential sites (GWPS). This paper analyzes the ground-water potentials in a semi-arid region of Khyber Pakhtunkhwa, Pakistan. It describes a standard methodology to identify and map GWPS using integrated Geographical Information System (GIS) and remote sensing (RS) methods. Eight parameters including elevation, slope, drainage density, lineaments density, soil, geology, land use/land cover and rainfall were integrated to explore areas with groundwater holding capability. GWPS were delineated through subjective weights assigned after coupling various thematic layers using Saaty’s Analytical Hierarchical Process (AHP). The modelled GWPS were cross-checked with tube wells data. The result indicates that the central part of the study area has good potential for groundwater reserves/exploitation, where the factors i.e. moderate to high drainage density, sedimentary sequence of alluvial plain, low elevation etc. discern the central portion of the study area as a suitable site for groundwater. This study suggests that the applied method proves to be very significant and reliable tool for timely assessment of quality assured evaluation of groundwater resources. This study could be a systematic guide for future investigations for water related explorations, especially in semi-arid environments.

Groundwater is an eco-environmental factor and critical resource required for human life and socioeconomic development. Understanding the evolution of groundwater chemistry and its controlling factors are imperative for preventing its deterioration and ensuring its sustainable use. We studied the characteristics of groundwater chemistry in the Huangshui River Basin in Qinghai Province, China using hydrochemical techniques. Additionally, we identified the controlling factors of groundwater chemistry in this region using multivariate statistical techniques. Seventeen hydrochemical parameters of groundwater were investigated at 156 sites in June 2019. The results showed that total hardness, Fe, NO3−, SO42−, and Cl− were primary pollution factors of groundwater in this region, and that 33.3%, 35.3%, 8.97%, 23.1%, and 7.69% of the samples exceeded Grade III standards for groundwater quality in China, respectively. Land use types also significantly affected groundwater hydrochemistry. The hydrochemical composition of groundwater in industrial areas is more strongly influenced by human activities. The major hydrochemical types identified in the region were HCO3-Ca·Mg and HCO3·SO4-Ca·Mg. Additionally, high proportions of SO4 (50.6%), Na (32.1%), and Cl (13.5%) groundwater types revealed the influence of anthropogenic activities on the groundwater hydrochemistry. Rock weathering was the major factor influencing the groundwater hydrochemistry, while evaporation–condensation and anthropogenic activities also influenced the hydrochemical characteristics of groundwater. The hydrochemical composition of groundwater was mainly controlled by silicate rock weathering. The main controlling factors of groundwater hydrochemistry were water–rock interactions, “physicochemical” factors (nature processes), domestic sewage, chemical fertilizer, and industrial sewage (human activities).

Abstract. In Germany, 70 % of the drinking water demand is met by groundwater, for which the quality is the product of multiple physical–chemical and biological processes. As healthy groundwater ecosystems help to provide clean drinking water, it is necessary to assess their ecological conditions. This is particularly true for densely populated urban areas, where faunistic groundwater investigations are still scarce. The aim of this study is, therefore, to provide a first assessment of the groundwater fauna in an urban area. Thus, we examine the ecological status of an anthropogenically influenced aquifer by analysing fauna in 39 groundwater monitoring wells in the city of Karlsruhe (Germany). For classification, we apply the groundwater ecosystem status index (GESI), in which a threshold of more than 70 % of crustaceans and less than 20 % of oligochaetes serves as an indication for very good and good ecological conditions. Our study reveals that only 35 % of the wells in the residential, commercial and industrial areas and 50 % of wells in the forested area fulfil these criteria. However, the study did not find clear spatial patterns with respect to land use and other anthropogenic impacts, in particular with respect to groundwater temperature. Nevertheless, there are noticeable differences in the spatial distribution of species in combination with abiotic groundwater characteristics in groundwater of the different areas of the city, which indicate that a more comprehensive assessment is required to evaluate the groundwater ecological status in more detail. In particular, more indicators, such as groundwater temperature, indicator species, delineation of site-specific characteristics and natural reference conditions should be considered.

Abstract. A new model has been developed for assessing the effects of multiple sources of phosphorus on the water quality and aquatic ecology in heterogeneous river systems. The Integrated Catchments model for Phosphorus (INCA-P) is a process-based, mass balance model that simulates the phosphorus dynamics in both the plant/soil system and the stream. The model simulates the spatial variations in phosphorus export from different land use types within a river system using a semi-distributed representation, thereby accounting for the impacts of different land management practices, such as organic and inorganic fertiliser and wastewater applications. The land phase of INCA-P includes a simplified representation of direct runoff, soilwater and groundwater flows, and the soil processes that involve phosphorus. In addition, the model includes a multi-reach in-stream component that routes water down the main river channel. It simulates Organic and Inorganic Phosphorus concentrations in the land phase, and Total Phosphorus (dissolved plus particulate phosphorus) concentrations in the in-stream phase. In-stream Soluble Reactive Phosphorus concentrations are determined from the Total Phosphorus concentrations and the macrophyte, epiphyte and algal biomasses are simulated also. This paper describes the model structure and equations, the limitations and the potential utility of the approach. Keywords: modelling, water quality, phosphorus, soluble reactive phosphorus, basin management

One of the important tasks of modern agroecology is the study of the patterns of circulation in the biosphere of chemical elements that are regulators of biological processes. The goal – is to determine the quantitative and qualitative effect of heavy metals in soil on crop yields and beneficial properties of products obtained. At the same time, it was found that soil contaminated with heavy metals not only worsens the quality of products and food, but also reduces cadastral value of land. Methods – economic and statistical in analysis and assessment of the current state, abstract and logical, used to identify industry and regional characteristics. Results – urgent problem of degradation of agricultural lands, their desertification in the Republic of Kazakhstan is considered. The conducted research shows that the content of lead and arsenic corresponds to the norm, and cadmium and mercury exceed the normative indicators and do not meet food safety requirements. Conclusions – heavy metals lead, cadmium, mercury, arsenic are toxic even in very low concentrations. Heavy metals enter agricultural lands from mineral fertilizers and plant protection products. It is generally accepted that their effect is negative if the yield is significantly reduced by 10% or more. It is necessary to carry out a detailed survey of the sphere of agricultural production on contaminated soils. It is practically impossible to reduce total concentration of heavy metals in unproductive arable land, but it is possible to significantly reduce their mobility and make them less accessible to plants, reduce accumulation of toxic substances in their biomass, improve the quality of land plots and, accordingly, their cadastral price.

Subsurface VOC monitoring has been mainly based on manual sampling, transport, and analysis, which would require a sufficient amount of samples to ensure data accuracy and reliability, and additional costs to ensure sample quality. Therefore, a continuous on-site monitoring system is desirable for accurate measurement and subsequent risk assessment. In this study, benzene, toluene, ethylbenzene, and xylene (BTEX) were continuously monitored by the system based on a thermal desorber (TD) and gas chromatography (GC) in an oil-contaminated site that consisted of saturated and unsaturated zones. For the saturated zone, fully automated groundwater sampling and purging processes were performed, and the gasified samples were applied to the TD–GC system. For the unsaturated zone, the gaseous sample in the site was directly applied to the TD–GC system. After verifying the accuracy and precision of the monitoring system, the continuous monitoring system was successfully operated for more than a month in the field. The monitoring system used in this study is applicable to other sites for continuous monitoring, thus providing a scientific background for advanced risk assessment and policy development.

Water resources are scarce in the Northeastern Loess Plateau, and water cellar water (WCW) is a vital water resource available in the vast rural areas of the region. The quality of WCW was assessed by principal component analysis (PCA) and Nemerow’s pollution index (NPI) for different rainfall catchment areas, depths, and storage times. Eleven indicators were measured, including pH, electrical conductivity (EC), F−, Cl−, NO3−, SO42−, Na+, NH4+, Ca2+, Mg2+, and K+. The results show that the tap water quality in the rural areas of the Northeastern Loess Plateau is above the second level and meets the drinking water standard (DWS), which is similar to the tap water quality in the region. The main component score of water quality from tile roof + cement ground (I) is 0.32, and the Nemero index is 0.41; the principal component score of water quality from cement ground (I) is 0.45, and the Nemero index is 0.29; the principal component score of water quality from trampled land (I) is 0.59, and the Nemero index is 0.44; the principal component score of water quality from tile roof + trampled land (II) is 1.87, and the Nemero index is 1.10. The rainwater harvesting catchment area of tile roof + cement ground (I) ensured the highest water quality, followed by cement ground (I), trampled ground (I), and tile roof + trampled ground (II). The water quality of the catchment area for artificially collected rainwater (roof tile surface, cement ground, etc.) was better than that of the original soil (trampled ground). The highest water quality was found at a storage time of 1 year (I), followed by 2.5 years (I), and 2 months (II). A depth of 4 m (I) contributed to the highest water quality, followed by 2 m (II), 3 m (II), and 1 m (II). Water quality improved with the increasing depth of WCW. The rainfall and WCW in the area were weakly alkaline, and the groundwater was contaminated with NO3−. PCA’s water quality assessment results were similar to the NPI method, indicating that both methods can be used in combination for unconventional water quality assessment.

Olive mill wastewater (OMW) is a compound originating from oil mills during oil extraction processes. In the Mediterranean area, more than 30 million m3 of OMW are produced each year, which represents 95-97% of the world production. Such volumes of untreated OMW are usually directly disposed of into drainage systems, water bodies (such as streams, lagoons and ponds) or are sprinkled on soils, causing potentially severe environmental problems to soils and groundwater. Consequently, there is a serious waste management problem related to the olive oil industry, because these practices no longer being acceptable. In the case of on-land OMW disposal, the characterization and the identification of this contaminant in soils is a fundamental task especially with a view to maintaining the integrity and quality of agroecosystems. In recent years, soils have been extensively studied to detect contaminants by using various geophysical methods. Among such techniques, time domain reflectometry (TDR) has shown, in different contexts, evident sensitivity and resolution capability for the characterization of contaminated soil sites. In order to further exploit the potential of the TDR technique, in this study we conducted a series of laboratory-controlled tests to explore how OMW influences the dielectric response of contaminated soils. This investigation led to the development of an empirical dielectric model to estimate the presence of OMW in variably saturated-contaminated soils with different textures and pedological features. In particular, the soils selected belong to two typical pedological units in southern Italy which account for approximately 90% of the Italian olive plantations and one of the highest concentrations of the olive oil industry in Italy. In these districts, as well as in other European and Mediterranean countries, there is the controversial habit to spread OMW on soils.

From 2014 to 2020, a full-scale horizontal well was operated to investigate the performance of full-scale riverbank filtration (RBF) in the Nakdong River in Korea, which is significantly impacted by the effluents from sewage treatment plants. In this study, an individual lateral full-scale horizontal collector well was investigated for the first time in Korea, and its performance was determined based on the turbidity and levels of iron, total nitrogen, dissolved organic matter, and four selected trace organic contaminants (TrOCs) (tebuconazole, hexaconazole, iprobenfos, and isoprothiolane) in the RBF and Nakdong River. The turbidity of the river was high with an average of 10.8 NTU, while that of the riverbank filtrate was 0.5 NTU or less on average. The average dissolved organic carbon (DOC) concentrations were 2.5 mg/L in the river water and 1.4 mg/L in the riverbank filtrate, which indicated a 44% reduction in DOC content during the RBF. Out of the 10 laterals, 8 laterals exhibited similar levels of iron, manganese, total nitrogen, DOC, and total hardness, electrical conductivity, and turbidity. The characteristics of the remaining two laterals were different. Because the groundwater inflow was relatively low (<10%), the laterals were contaminated by agricultural land use before the installation of the RBF. This is the first study to report changes in water quality according to individual laterals in a river affected by wastewater effluents. The filtration unit exhibited more than 90% removal rates for tebuconazole and hexaconazole. However, the removal rate for iprobenfos was approximately 77%, while that for isoprothiolane was 46%. The four selected TrOCs in this study were not detected in the groundwater. We found that some organic micropollutants were effectively removed by the RBF.

Soil salinization, as one of the threats of land degradation, is the main environmental issue in Uzbekistan due to its aridic climate. One of the most vulnerable areas to soil salinization is Sirdarya province in Uzbekistan. The main human-induced causes of soil salinization are the insufficient operation of drainage and irrigation systems, irregular observations of the agronomic practices, and non-efficient on-farm water use. All of these causes considerably interact with the level of the groundwater, leading to an increase in the level of soil salinity. The availability of historical data on actual soil salinity in agricultural lands helps in formulating validated generic state-of-the-art approaches to control and monitor soil salinization by remote sensing and geo-information technologies. In this paper, we hypothesized that the Soil-Adjusted Vegetation Index-based results in soil salinity assessment give statistically valid illustrations and salinity patterns. As a study area, the Mirzaabad district was taken to monitor soil salinization processes since it is the most susceptible territory of Sirdarya province to soil salinization and provides considerably less agricultural products. We mainly formulated this paper based on the secondary data, as we downloaded satellite images and conducted an experiment against the in-situ method of soil salinity assessment using the Soil-Adjusted Vegetation Index. As a result, highly saline areas decreased by a factor of two during the studied period (2005–2014), while non-saline areas increased remarkably from a negligible value to over 10 000 ha. Our study showed that arable land suitability for agricultural purposes has been improving year by year, and our research held on this district also proved that there was a gradual decrease in high salt contents on the soil surface and land quality has been improved. The methodology has proven to be statistically valid and significant to be applied to other arid zones for the assessment of soil salinity. We assume that our methodology is surely considered as a possible vegetation index to evaluate salt content in arable land of either Uzbekistan or other aridic zones and our hypothesis is not rejected by this research.

Abstract. Isotope mass balance models have undergone significant developments in the last decade, demonstrating their utility for assessing the spatial and temporal variability in hydrological processes and revealing significant value for baseline assessment in remote and/or flood-affected settings where direct measurement of surface water fluxes to lakes (i.e. stream gauging) are difficult to perform. In this study, we demonstrate that isotopic mass balance modelling can be used to provide evidence of the relative importance of direct floodwater inputs and temporary subsurface storage of floodwater at ungauged lake systems. A volume-dependent transient isotopic mass balance model was developed for an artificial lake (named lake A) in southern Quebec (Canada). This lake typically receives substantial floodwater inputs during the spring freshet period as an ephemeral hydraulic connection with a 150 000 km2 large watershed is established. First-order water flux estimates to lake A allow for impacts of floodwater inputs to be highlighted within the annual water budget. The isotopic mass balance model has revealed that groundwater and surface water inputs account for 60 %–71 % and 39 %–28 % of the total annual water inputs to lake A, respectively, which demonstrates an inherent dependence of the lake on groundwater. However, when considering the potential temporary subsurface storage of floodwater, the partitioning between groundwater and surface water inputs tends to equalize, and the lake A water budget is found to be more resilient to groundwater quantity and quality changes. Our findings suggest not only that floodwater fluxes to lake A have an impact on its dynamics during springtime but also significantly influence its long-term water balance and help to inform, understand, and predict future water quality variations. From a global perspective, this knowledge is useful for establishing regional-scale management strategies for maintaining water quality at flood-affected lakes, for predicting the response of artificial recharge systems in such settings, and for mitigating impacts due to land use and climate changes.

Agriculture has significantly aided in meeting the food needs of growing population. In addition, it has boosted economic development in irrigated regions. In this study, an assessment of the groundwater (GW) quality for agricultural land was carried out in El Kharga Oasis, Western Desert of Egypt. Several irrigation water quality indices (IWQIs) and geographic information systems (GIS) were used for the modeling development. Two machine learning (ML) models (i.e., adaptive neuro-fuzzy inference system (ANFIS) and support vector machine (SVM)) were developed for the prediction of eight IWQIs, including the irrigation water quality index (IWQI), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), potential salinity (PS), residual sodium carbonate index (RSC), and Kelley index (KI). The physicochemical parameters included T°, pH, EC, TDS, K+, Na+, Mg2+, Ca2+, Cl−, SO42−, HCO3−, CO32−, and NO3−, and they were measured in 140 GW wells. The hydrochemical facies of the GW resources were of Ca-Mg-SO4, mixed Ca-Mg-Cl-SO4, Na-Cl, Ca-Mg-HCO3, and mixed Na-Ca-HCO3 types, which revealed silicate weathering, dissolution of gypsum/calcite/dolomite/ halite, rock–water interactions, and reverse ion exchange processes. The IWQI, SAR, KI, and PS showed that the majority of the GW samples were categorized for irrigation purposes into no restriction (67.85%), excellent (100%), good (57.85%), and excellent to good (65.71%), respectively. Moreover, the majority of the selected samples were categorized as excellent to good and safe for irrigation according to the SSP and RSC. The performance of the simulation models was evaluated based on several prediction skills criteria, which revealed that the ANFIS model and SVM model were capable of simulating the IWQIs with reasonable accuracy for both training “determination coefficient (R2)” (R2 = 0.99 and 0.97) and testing (R2 = 0.97 and 0.76). The presented models’ promising accuracy illustrates their potential for use in IWQI prediction. The findings indicate the potential for ML methods of geographically dispersed hydrogeochemical data, such as ANFIS and SVM, to be used for assessing the GW quality for irrigation. The proposed methodological approach offers a useful tool for identifying the crucial hydrogeochemical components for GW evolution assessment and mitigation measures related to GW management in arid and semi-arid environments.

Abstract. Watershed-scale modeling can be a valuable tool to aid in quantification of water quality and yield; however, several challenges remain. In many watersheds, it is difficult to adequately quantify hydrologic partitioning. Data scarcity is prevalent, accuracy of spatially distributed meteorology is difficult to quantify, forest encroachment and land use issues are common, and surface water and groundwater abstractions substantially modify watershed-based processes. Our objective is to assess the capability of the Soil and Water Assessment Tool (SWAT) model to capture event-based and long-term monsoonal rainfall–runoff processes in complex mountainous terrain. To accomplish this, we developed a unique quality-control, gap-filling algorithm for interpolation of high-frequency meteorological data. We used a novel multi-location, multi-optimization calibration technique to improve estimations of catchment-wide hydrologic partitioning. The interdisciplinary model was calibrated to a unique combination of statistical, hydrologic, and plant growth metrics. Our results indicate scale-dependent sensitivity of hydrologic partitioning and substantial influence of engineered features. The addition of hydrologic and plant growth objective functions identified the importance of culverts in catchment-wide flow distribution. While this study shows the challenges of applying the SWAT model to complex terrain and extreme environments; by incorporating anthropogenic features into modeling scenarios, we can enhance our understanding of the hydroecological impact.

Abstract. Pesticides are contaminants of priority concern that continue to present a significant risk to drinking water quality. While pollution mitigation in catchment systems is considered a cost-effective alternative to costly drinking water treatment, the effectiveness of pollution mitigation measures is uncertain and needs to be able to consider local biophysical, agronomic, and social aspects. We developed a probabilistic decision support tool (DST) based on spatial Bayesian belief networks (BBNs) that simulates inherent pesticide leaching risk to ground- and surface water quality to inform field-level pesticide mitigation strategies in a small (3.1 km2) drinking water catchment with limited observational data. The DST accounts for the spatial heterogeneity in soil properties, topographic connectivity, and agronomic practices; the temporal variability of climatic and hydrological processes; and uncertainties related to pesticide properties and the effectiveness of management interventions. The rate of pesticide loss via overland flow and leaching to groundwater and the resulting risk of exceeding a regulatory threshold for drinking water was simulated for five active ingredients. Risk factors included climate and hydrology (e.g. temperature, rainfall, evapotranspiration, and overland and subsurface flow), soil properties (e.g. texture, organic matter content, and hydrological properties), topography (e.g. slope and distance to surface water/depth to groundwater), land cover and agronomic practices, and pesticide properties and usage. The effectiveness of mitigation measures such as the delayed timing of pesticide application; a 10 %, 25 %, or 50 % reduction in the application rate; field buffers; and the presence/absence of soil pan on risk reduction were evaluated. Sensitivity analysis identified the month of application, the land use, the presence of buffers, the field slope, and the distance as the most important risk factors, alongside several additional influential variables. The pesticide pollution risk from surface water runoff showed clear spatial variability across the study catchment, whereas the groundwater leaching risk was uniformly low, with the exception of prosulfocarb. Combined interventions of a 50 % reduced pesticide application rate, management of the plough pan, delayed application timing, and field buffer installation notably reduced the probability of a high risk of overland runoff and groundwater leaching, with individual measures having a smaller impact. The graphical nature of BBNs facilitated interactive model development and evaluation with stakeholders to build model credibility, while the ability to integrate diverse data sources allowed a dynamic field-scale assessment of “critical source areas” of pesticide pollution in time and space in a data-scarce catchment, with explicit representation of uncertainties.

In order to increase the efficiency of land use- and territorial planning, cartographic materials of various thematic contents are required. In the article, the authors propose a methodology of assessing and mapping the favorability of the natural and agricultural potential of landscapes for agricultural use to increase its efficiency using GIS technologies. It is proposed to obtain information on landscapes by means of geoecological assessment, including a multivariate mathematical-cartographic, and spatial analysis of landscape conditions for sustainable environment-friendly agricultural production. Geoecological conditions make an integral indicator of the natural and agricultural landscape. To assess the land for agricultural production, maps are used, according to which the quality of the land plot is determined through the convolution of normalized indicators of the territory’s favorability, while the map is created in the GIS environment of spatially-linked information on the degree of the agro-resource suitability and geoecological conditions for agricultural production. Indicators of agro-resource and geoecological state of landscapes were established. The first ones include the agroclimatic potential and soil bonitet, and the second – the ecological and geochemical resistance of soils to acidification, erosion, ecosystem diversity of the territory, the density of the hydrographic network, the depth of groundwater, and the erosion potential of the relief. The developed technique is tested on Volkhov landscape of Leningrad oblast. The aim of the research is to develop a methodology for assessing and mapping the natural and agricultural potential of landscapes in the GIS environment and to test it on the territory of the region.

Monitoring can be considered one of the main methods of solving the problem of pedosphere pollution, because the necessary information to overcome the problems can be obtained only through the large-scale specific study. At present, there are some monitoring programs aimed at solving the problems, but they are not effective enough and, therefore, cannot completely fulfill their tasks. The current problems of land monitoring in Ukraine are primarily related to its organization, which could provide the comprehensive and systematic accounting and assessment of the status of land in order to protect and improve the quality of agricultural soils. There is a need to create a permanent system of accounting, observation, comparison, measurement, inventory and forecasting of the ecological status of lands with the detection and registration of changes against the background of natural and anthropogenic processes, in the continuous functioning of the ecological monitoring service of land. Analyzing the studies in the field of monitoring the oil-contaminated soil on the territory of oil and gas fields, it becomes necessary to develop the new methods of ecological monitoring of the soil of depleted oil and gas fields in order to study the problem of pedosphere contamination. The development results of a new method of environmental soil monitoring in depleted oil and gas fields are described. The method allows obtaining adequate information on the studied area. An important role in the new monitoring scheme is played by the method of locating soil sampling points, the benefits of which are the system’s flexibility in relation to the studied territory and complexity of research that does not necessarily depend on the size of the studied area. The proposed schemes introduce a new view of monitoring the soil, which is subjected to the heavy anthropogenic impact of the mining industry. The analyzed schemes help to develop new reclamation methods of the soil located in the depleted oil and gas fields, which is contaminated with hydrocarbons and drilling waste.

Abstract The aim of the study was to examine the effects of tillage methods on surface runoff and model the pattern and processes of surface water pollution associated with tillage methods using Soil Water Assessment Tool (SWAT). This model was designed to predict the impact of land management practices on water, sediment, and varying tillage types in watersheds over two planting seasons. Traditional heap (T), Plough/Harrow (PH), Plough/Harrow/Ridge (PHR) and No-tillage (NT) methods commonly used in the study area were applied to experimental plots at Unilorin Teaching and Research Farm and National Center for Agricultural Mechanization, Idofian (Nigeria). Using Randomized Complete Block Design (RCBD), each treatment had three replicates making 12 experimental plots at each location for the 2015 and 2016 planting season. Nine biophysical parameters were purposively selected, examined and modelled. The study revealed that four of nine biophysical factors (sediment yield: 10.54 t/ha; groundwater discharge: 174.45 mm; organic nitrogen: 62.62 kg/ha, and nitrogen in surface runoff: 5.15 kg/ha) were higher for traditional heaps, while three parameters (surface runoff: 374.42 mm; evapotranspiration: 752.78 mm, and soil loss: 1.05 kg/ha) were higher under plough/harrow and plough/harrow/ridge cultivation practices. The study concluded that tillage methods have impact on water quality. However, plough/harrow has comparatively more favorable effect on the contribution to surface runoff. It is therefore recommended that this type of tillage should be adopted to reduce water pollution and for sustainable environment.

Chlorinated organic compounds (COCs) are a serious threat to human health and the ecological environment due to their toxicity, mutagenicity and carcinogenicity. A number of corresponding treatment techniques have been developed thus far; among these techniques, adsorption is considered an efficient and low-cost method. However, it is very important to find suitable and economical adsorbent types and usage amounts. In this study, the adsorption of trichloroethylene (TCE) and perchloroethylene (PCE) onto two different adsorbents (silica gel and activated carbon) was investigated, and the obtained adsorption constants were then introduced into Langmuir and Freundlich adsorption models. The adsorption isotherm constants of these two models were used to predict the adsorbate removal efficiency and the required adsorbent mass. The results showed that the Langmuir and Freundlich models predicted the removal efficiency and adsorbent quality of the TCE and PCE adsorbed onto silica gel and activated carbon, and the errors were less than 10% compared with the measured values obtained through adsorption experiments. According to the differences in adsorption efficiency and cost between silica gel and activated carbon, it was found that, when the adsorption efficiency of the silica gel for TCE and PCE significantly decreased, adding activated carbon to continue the adsorption effectively reduced the adsorption cost of on-site remediation. This result was demonstrated by taking the Radio Corporation of America (RCA) pollution incident in Taiwan as an example, and it was estimated that 6427 ± 172 tons and 343 ± 21 tons of silica gel and activated carbon, respectively, would be required for the on-site remediation of TCE, and the total cost would be approximately 4,390,000 USD. The remediation of PCE would require 7553 ± 57 tons of silica gel and 350 ± 68 tons of activated carbon, with a total cost of approximately 5,030,000 USD. Therefore, silica gel should be used to reduce the pollutant concentration first, and then activated carbon should be added for continuing adsorption. This method of adding adsorbents is economical and can effectively reduce the adsorption cost.

Sea surface temperature (SST) is a key hydrological variable which can be monitored via satellite. One source of thermal data with a spatial resolution high enough to study sub-mesoscale processes in coastal waters may be the Landsat mission. The Thermal Infrared Sensor on board Landsat 8 collects data in two bands, which allows for the use of the well-known nonlinear split-window formula to estimate SST (NLSST) using top-of-the-atmosphere (TOA) brightness temperature. To calibrate its coefficients a significant number of matchup points are required, representing a wide range of atmospheric conditions. In this study over 1200 granules of satellite data and 12 time series of in situ measurements from buoys and platforms operating in the Baltic Sea over a period of more than 6 years were used to select matchup points, derive NLSST coefficients and evaluate the results. To filter out pixels contaminated by clouds, ice or land influences, the IdePix algorithm was used with Quality Assessment Band and additional test of the adjacent pixels. Various combinations of flags were tested. The results show that the NLSST coefficients derived previously for coastal areas, characterised by a more humid atmosphere, might overestimate low SST values. Formulas derived for the Baltic Sea produced biases close to 0 °C and RMSEs in the range of 0.49–0.52 °C.

Technogenic pollution of the territory firstly leads to decrease of productivity of the land, since the main part of the technogenic loading, as a result of such pollution, assumes to the soil and vegetation. Soils those have been contaminated are characterized by changed structural and physical-and-chemical properties, which does not allow them to be used for economic purposes. To detect the technogenic loading on the soil as a result of the chemical plant operation, soil quality studies were carried out using the bio-testing method. The most informative data towards ecological danger of ecosystem pollution is the results of the determination of phytotoxicity for soil organisms. Such information can be obtained by an integral assessment of the biological usefulness of the habitat of organisms using the bio-testing method, which provides registration in controlled, standard conditions of the corresponding reactions of test organisms to the toxic effects of ecologically hazardous chemical compounds and their mixes. The following higher plants were selected as test cultures: Raphanus sativus L., Hordeum vulgare L. and Triticum aestivum L. As the test-response of higher plants, the energy of seed germination, the length of the sprout and the length of the root were taken into account. Four zones were selected for the research. The largest difference between the values of germination energy between control and experiment was observed on the results of a test-response to Hordeum vulgare L. in a sample of soil from zone Nr 4. The indicator of the toxic effect detected on the territory of zone Nr 4 - 43,64% reduction in the length of the roots relative to the control; 33.81% reduction in the length of the germs relative to the control based on the results of the test-response to Hordeum vulgare L. The soil sample from the zone Nr 1 showed no toxic properties in any test reaction (6.32% decrease in root length relative to control one, 5.68% reduction length of germs relative to the control one based on the results of the test reaction on Raphanus sativus L. Sample of soil from zone Nr 2 did not show toxicity (-45.26% decrease in root length relative to control one and 8.61% decrease in germination length relative to control one revealed by the results of the test-response to Raphanus sativus L. Soil samples from zone Nr 3 also showed no toxicity (3.83% decrease in root length relative to control and 11.02% reduction in germination length relative to control revealed by test-reaction results on Raphanus sativus L. The table value of the Student's criterion for the probability level is P = 0.5 and the number of measures of freedom 58 is 2.01. The calculation of the actual value of Student's criterion for the length of the roots (2.68) and the germs (2.05) showed an excess of the table value based on the results of the test-response on Hordeum vulgare L. in the soil sample from zone Nr 4, what confirms the presence of toxic properties of the soil. In order to assess the risk of soil contamination, the "measure of soil contamination" indicator was used in accordance with defined levels of inhibition of growth processes, the quantitative characteristics of which are expressed by the soil contamination coefficient, while the soil contamination coefficient is differentiated according to the levels of inhibition of growth processes. According to the calculated data, in the sample Nr 4, the phytotoxic factor or percentage reduction in the length of the roots relative to the control is 43.64% based on the results of the test-response to Hordeum vulgare L. By level of contamination, the soil is moderately polluted, belongs to the III class of quality and shows the measure of contamination of 1,3. Soil samples №1, №2 and №3 showed no toxicity (А˂20), i.e., they are non-contaminated and belong to the I class of quality. Therefore, for the integrated assessment of soil quality, in addition to chemical indicators, it is recommended to use integral indicators, in particular phytotoxicity of the soil, which characterizes the biological usefulness of the habitat of organisms.

Evaluation and verification of the WetSpa model based on selected rural catchments in Poland The paper presents results of calibration and verification of the WetSpa model, which enables the modelling of rainfall-runoff process based on mass and energy balance in the soil-plantatmosphere system in the catchment. It is a model with distributed parameters, using the structure of raster GIS model to determine the spatial diversity of the catchment environment. This enables simulation of runoff from the catchment, including: precipitation, evapotranspiration, interception of plant surface and soil cover, infiltration and capillary rise in soil and groundwater runoff. Simulated processes depend on the required non-distributed parameters, which were calibrated based on hydrometeorological data from the three rural catchments with different physical and geographical characteristics: Mławka, located in the Wkra basin in Central Poland and the rivers Kamienna and Sidra, which are tributaries of the upper Biebrza in north-eastern part of the country. Distributed catchment parameters were specified on the basis of digital soil maps, land use maps and digital elevation model using GIS techniques. Non-distributed model parameters were calibrated for the three catchments using automatic techniques based on the PEST algorithm. The obtained values of these parameters were scrutinized in order to analyse differences resulting from various characteristics of the study areas. The quality of the model was verified upon dependent and independent data. Appropriate quality measures, including Nash-Sutcliffe efficiency measure, were used to assess model quality. For two catchments (the Sidra and Kamienna) the model showed a satisfactory quality for modelling high flows, it was, however, not satisfactory for low flows. The values for the Mławka catchment justified the assessment of the model quality measurements as very good and good. The factors most affecting the process of river outflow formation were determined using the analysis of model sensitivity to relative changes in parameter values. It was found that the evaluation of the model quality depended largely on the quality of meteorological data and proper parameterization of the soil cover.

Abstract. The role of soil properties and their spatial distribution in the landscape are already recognised as crucial issues greatly affecting rainfall-runoff dynamics and hence landscape hydrology. This becomes even more important when hydrological monitoring data are lacking. This applies to the critical issue of making hydrological predictions for ungauged basins. The rapid development of hydropedology along with Digital Soil Mapping (DSM) is promising to both enhance our understanding and (spatial) prediction capacity of rainfall-runoff processes and to be a powerful tool for environmental policy research. Despite these developments and broad conceptualizations, the crucial point as to how the soil data from typically available soil mapping databases can be usefully employed by the hydrologist has yet to be addressed. This question implies detailed knowledge of the quality and quantity of information embedded in and behind a soil map. This work produced an analytical evaluation of the potential and limitations of soil data obtained through soil surveys and soil mapping. This evaluation is made from a landscape hydrology viewpoint and is also developed through the following Italian case studies: irrigation management at the district scale, assessment of groundwater vulnerability, flood peak forecasting, and land evaluation for maize production. We show that special care is required in handling soil database data if their full potential is to be achieved. Further, all the case studies agree on the appropriate degree of complexity of the soil hydrological model to be applied. We also emphasise that effective interaction between pedology and hydrology to address landscape hydrology requires (i) better awareness of the hydrologic community about the type of soil information behind a soil map or soil database, (ii) the development by the pedological community of a better quantitative framework for evaluating surveyed hydrological features, and (iii) quantitative information on soil spatial variability and, if possible, on the spatial distribution of prediction errors.

Long-term research on gauged watersheds within the USDA Forest Service’s Experimental Forest and Range (EFR) network has contributed substantially to our understanding of relationships among forests, water, and hydrologic processes and watershed management, yet there is only limited information from coastal forests. This article summarizes key findings from hydrology and water-quality studies based on long-term monitoring on first-, second-, and third-order watersheds on the Santee Experimental Forest, which are a part of the headwaters of the east branch of the Cooper River that drains into the harbor of Charleston, South Carolina. The watersheds are representative forest ecosystems that are characteristic of the low-gradient Atlantic Coastal Plain. The long-term (35-year) water balance shows an average annual runoff of 22% of the precipitation and an estimated 75% for the evapotranspiration (ET), leaving the balance to groundwater. Non-growing season prescribed fire, an operational management practice, shows no effects on streamflow and nutrient export. The long-term records were fundamental to understanding the effects of Hurricane Hugo in 1989 on the water balance of the paired watersheds that were related to vegetation damage by Hugo and post-Hugo responses of vegetation. The long-term precipitation records showed that the frequency of large rainfall events has increased over the last two decades. Although there was an increase in air temperature, there was no effect of that increase on annual streamflow and water table depths. The long-term watershed records provide information needed to improve design, planning, and assessment methods and tools used for addressing the potential impacts of hydrologic responses on extreme events; risk and vulnerability assessments of land use; and climate and forest disturbance on hydrology, ecology, biogeochemistry, and water supply.

The quantity of municipal solid waste (MSW) generation is escalating at an alarming rate with every passing year alongside the modernization of our economy. Unfortunately, the majority of this waste remains uncollected or ends up in open dumping and followed by uncontrolled burning. Citing the deep-rooted consequences, open dumping should be absolutely abandoned and scientific interventions should be aggressively exercised to reclaim the municipal brownfields. The present research work undertook the judicial task of assessing the comparative feasibility of biomining and scientific capping as a technology selection for reclamation of about a decade old 120 million tons of waste chunk laying at Jawahar Nagar dump yard. Primary dump samples were collected from various locations, considering depth as a variable. While leachate and groundwater samples were collected from Malkaram lake and preinstalled borewells receptively. Additionally, the ambient air quality and noise level also been ascertained within the buffer zone. The blended representative solid sample was segregated using a 70 mm mesh size trommel into organic and inorganic fractions. The organic fraction was composted using a lab-scale aerobic static pile composting (ASPC) while the trommel reject was processed as refuse derived fuel (RDF). Evidently, the compost lagged quality and depicted nutrient deficiency. While the burning of RDF produced siloxane gas, significantly due to elevated silicon level in the primary waste. Furthermore, due to the prolonged leaching tenure and seasonal dilution, the concentration of legacy leachate was relatively weaker. Borewell samples collected from a depth of 20 feet also portrayed minor contamination up to 500 meters horizontal radius. The issue of leachability can solely be resolved with the capping of the existing dump and the end product quality derived from the biomining process is highly questionable. Thus, handling such large quantity capping is a befitting option over biomining for Jawahar Nagar dumpsite. INTRODUCTION Presently, in India due to rapid urbanization and industrialization, the generation of MSW has been increasing tremendously and also expected to continue a similar trend in the future (Scott, 1995; Bhat et al., 2017; Sethurajan et al., 2018; Sharma et al., 2018). Annually, the comprehensive urban MSW generation in India is more than 62 million tons. Metro cities are the mammoth contributor of the entire chunk and waste production had already reached an alarming figure of 50,000 tonnes/day. While the waste generation from the tier 2 cities is also rigorously escalating and presently contribute up to 20,000 tones/day (Sharma et al., 2018). A study conducted by the central pollution control board (CPCB) revealed MSW generation in India is increasing at a distressing rate of 5 % per annum with a sharp escalation in the quantities of domestic hazardous waste (Sharma et al., 2018). With major financial constraints, inefficacy of collection, treatment, and disposal incurs further reasons to worry. So far India has miserably failed to set up wholesome source segregation and collection method. Presently, the country spends more than 60% of its annual waste management budget only in collection. Besides, only 20% or less of the collected materials are scientifically handled and treated. Citing the statistics, it is evident that the majority of the MSW is simply gets dumped on the low laying grounds located somewhere on the outskirts of the cities. The precipitation, infiltration, surface water runoff, bird menace, rodent interference etc. triggers the vulnerability of waste and leads to mal odor, ground and surface water contamination, human and environmental health deterioration (Jayawardhana et al., 2016). Further, the perseverance of the inorganic and inert fractions leads to soil contamination, poses a fire threat, and also may incur carcinogenicity and acute toxicity among the animals (Mir et al., 2021). There are numerous techniques for the reclamation and remediation of the dumpsites, includes processes such as capping and closure, in-situ vitrification, sub-surface cut-off walls, and waste biomining (Chakrabarti and Dubey, 2015; Thakare and Nandi, 2016). Waste biomining is a stable way to get rid of the entire range of problems associated with open dumping and reclaim valuable land (Kaksonen et al., 2017). There are several instances including reclamation of Mumbai Gorai dump yard by IL & FS Environment, 70 – 80 years old 12,00,000 tons of dump clearance by Nagar Nigam Indore within a minute span of 3 years and many more. But the process of biomining is highly sensitive and case-specific. The success of the process solely depends on factors such as characteristics of the waste, efficacy of the effective microorganism culture, acceptability of the processed end product at the local market etc. (Jerez, 2017; Banerjee et al., 2017; Venkiteela, 2020). Contrarily, though the scientific capping is not an end-to-end solution but still advisable in the cases where the quantity of waste is gigantic, land scarcity is prevalent, no nearby industries to consume the end products etc. Mehta et al. (2018) have also supported the above claim based on the assessment of locations specific MSW dump reclamation case studies. While in another Nagpur-based case study conducted by Ashootosh et al. (2020) reported the superiority of the biominingprocess over simple land capping due to the favorability of the local conditions. Capping eliminates the environmental interference and thereby reduces biosphere contamination and leachate generation. Further, it captivates rodent and vector breeding and thereby curtails the spreading of communicable diseases and improves aesthetics. But right consolidation through compaction and execution is utmost necessary in the above case. As non-compaction and faulty sloping will easily lead to heavy settlement and slope failure (Berkun et al., 2005; Al-Ghouti et al., 2021). The present study has been pursued with the primary objective to run a techno-commercial assessment between scientific capping and biomining. While the secondary objective was to ascertain the level of contamination and propose mitigative measures. MATERIALS AND METHODStudy Area Spanning over 350 acres of a precious piece of land at the outskirts of Hyderabad city, Jawahar Nagar dumping yard was brutally utilized by the Greater Hyderabad Municipal Corporation (GHMC) for open dumping for a prolonged tenure of 10 years. It housed nearly 12 lakh metric tons of heterogeneous solid and domestic hazardous waste and continues polluting until 2015, until the Ramky group was offered to cap the legacy dumping and scientifically handle the site. The present study has been facilitated at Hyderabad Municipal Solid Waste Limited, formerly known as Jawahar Nagar dump yard to analyze and assess the feasibility of bio-mining as handling and management alternate to the existing practice of scientific capping. The epicenter of processing and disposal facility is lying approximately on the cross-section of 17°31'24.45"N and 78°35'23.37"E. As per the contract, the comprehensive legacy dumping to be capped in three phases over about 150 acres of area and Ramky has significantly entered the phase two of the operation only within a span of five years by successfully capping more than half of the legacy footprint. Sampling Methodology The waste pile was divided into three layers namely, base, middle, and top. A uniform amount of sample was collected from the successive layers of all five different corners which cover north, south, east, west, and central of the garbage pile. Sampling inspections were performed using a manual auger besides large samples were collected using a JCB excavator. The top six-inch layer of the pile was removed to avoid any contamination while collecting the samples and 5-10 kg of sample was collected from each of the locations. Further, intermediate and bottom layer samples were collected by digging a 500 mm diameter hole through the heap. A composite was prepared by a homogenized blending of all the fifteen grub samples. The blend was distributed into four equal quadrants and the top and bottom quadrants were eliminated diagonally while the left-over quadrants were mixed thoroughly. This process was repeated until a sample of the required bulk of 20 kg is obtained. Surface and subsurface water samples from borewell were collected in and around the facility. Piezometric monitoring borewells located near the landfills were utilized for the subsurface sample collection. While a rainwater pond turned leachate lake named Malkaram was determined as the primary source for leachate collection. Buffer samples were collected from Ambedkar Nagar, the nearby colony exiting at a distance of only 300 meters. Lab-scale Experimentation The representative sample was characterized for composition and further screened through a 70 mm mesh size trommel. The trommel permeate was considered as the organic fraction while the reject was mostly inorganics and inert. The organics were subjected to ASPC. The quantity of the air required is arrived using the method delineated below (Figure 1). MSW Pile size: 2m x 0.5m x 0.5m Volume of pile: 0.5 m3 Average Density of MSW: 620 Kg/m3 Weight of pile: 310 Kg Nitrogen required for matured compost: 9300 mg/kg dry : 9300 X 310 mg : 2.88 x 106 mg : 2.88 Kg Total air required: 2.88 x 100/76 [as Nitrogen in air is 76% by weight] : 3.79 Kg of dry air : 3.79/1.225 m3 [@ 15 deg C density of air 1.225 kg/m3] : 3.1 m3 This air is to be supplied for 100 min / day for 0.5 m pile Air flow rate required: 3.1 x 60/100 = 1.86 m3/h (for practical purpose a flowrate of 2 m3/h was maintained). The maturation period was considered as 28 days and post-maturation, the stabilized material was further cured for 24 hours and screened using 12 mm and 4 mm trommel respectively to obtain the desired product quality and particle size. Whereas, the trommel reject was evenly spreader on the copper trays and dried in an oven at 1050C for 2 hours. The dried material was micronized to the size of 50 mm or below using a scissor and inert such as glass, sand, stone etc. were segregated manually (Mohan and Joseph, 2020). Concurrently, a bench-scale capped landfill prototype was built using the below-mentioned procedure to evaluate the factors such as settlement and slope stability. A 30 mm thick low permeable soil was laid on the top of the waste, followed by a 60 mm layer of compacted clay liner (CCL). Each join between successive liner material was closely monitored. A 1.5 mm thick HDPE liner was placed on the top of the CCL. A 285 GSM geotextile membrane was placed as the successive above layer followed by a 15 mm thick drainage media layer. A further layer of geotextile membrane was placed on top of the drainage media for better stabilization, grip, and strength. The top vegetative soil layer of 45 mm thickness was laid off on top of the geotextile media and St. Augustine grass was rooted (Cortellazzo et al., 2020; Ashford et al., 2000). 2.4 Sample Analysis pH, Electrical Conductivity (EC) and Turbidity of the samples were analyzed using pH, EC-TDS, and Nephelometer of Mettler Toledo. The pH meter was calibrated with the buffer solution of 4.0, 7.0 & 9.12 at a controlled temperature. EC-TDS meter was calibrated with 0.1 M KCL having 12.8 mS/cm of conductivity. Nephelometer was calibrated with Formazine solution of 10 & 100 NTU. Total Dissolved Solids (TDS), (mg/L) was performed using the gravimetric method at 1800C in the oven. Titrimetric parameters such as Total Alkalinity as CaCO3 (mg/L), Total Hardness as CaCO3 (mg/L), Chloride as Cl- (mg/L), Calcium as Ca2+ (mg/L), Residual Free Chlorine (RFC), (mg/L) were analyzed using APHA (American Public Health Associations) method, 23rd Edition, 2017. Total Kjeldahl Nitrogen (mg/L) and Ammonical Nitrogen (mg/L) were performed through distillation followed by titration with H2SO4 as a titrant. Sulphide as S2- was done with the Iodometric method after distillation. Each titrimetric parameter was analyzed in triplicate after standardizing the titrant with required reagents and crossed checked by keeping a check standard. Sodium as Na (mg/L) and Potassium as K (mg/L) were performed using Flame Photometer. The photometer was calibrated with different standards from 10 to 100 (mg/L) standard solutions. The leachate sample was diluted enough to get the value within the standard range and cross-checked with check standards at the same time. Chemical Oxygen Demand (COD), (mg/L) was performed using the open reflux method for 2 hours at 1500C in COD Digestor. Biochemical Oxygen Demand (BOD), (mg/L) was performed using the alkali iodide azide method for 3 days. The samples were kept in a BOD incubator at 270C for 3 days. It was kept in duplicate to have a check on quality control. Sulphate was analyzed by the gravimetric method instead of turbidimetric or through UV-Visible spectrophotometer as its concentration was found more than 40 mg/L. Nitrate as NO3- was analyzed after filtration at 220-275 nm, while Hexavalent Chromium as Cr6+ was analyzed at 540 nm in the UV-Vis. Parameters like Cyanide as CN-, Fluoride as F-, and Phenolic Compounds were gone through a distillation process followed by UV-Vis. The distillation process ensures the removal of interferences presents either positive or negative. For the parameters like Total Iron or Ferric Iron, the samples were digested properly with the required reagents on the hot plate before analyzing in UV-Vis. For the metal analysis the water samples were digested at a temperature of 1000C using aqua regia as a media. The samples were digested to one-fourth of the volume on a hot plate. The recommended wavelengths as per APHA 3120 B were selected for each of the metals. The standard graph was plotted for each of the metals before analysis and crossed checked with the check standard at the same time. Parameters such as bulk density and particle size were performed through the certified beaker and sieve. The percentage of moisture content was estimated using the oven by keeping the compost sample for 2 hours at 1050C. C/N ratio was estimated through CHNS analyzer keeping sulfanilamide as a check standard. The analysis was performed by extracting the desired component in the desired solution prescribed in the method followed by converting the same from mg/L to mg/Kg. RESULTS AND DISCUSSION An exhaustive bench-study has been pursued and real-time samples were collected and analyzed for all possible parameters to determine the pros and cons attributed to both processes. The investigation begins by collecting the samples and concluded by impact assessment studies inclusive of the buffer zone. Both solid, liquid, and gaseous samples were precisely investigated to opt for the best solution. A detailed finding of the investigation is summarized below. Primarily, the representative solid sample was characterized through a manual separation process and the results are portrayed in Figure 1. Compost Characterization ASPC of the organic fraction has resulted in a recovery of 46.7% of the initial load. While 53.3% of the influent mass were inert and barely degradable fraction contributes to reject, the rest 4.1% is miscellaneous process loss. The processed compost was extensively analyzed including for metal contamination and the same is tabulated in Table 1. The value of C/N ratio, OC, TN, K2O, P2O5, and NPK evidently portrays the shortcoming in terms of nutrient availability. Though it is highly enriched in organic carbon and thus the same can be effectively utilized as a soil preconditioner. Ayilara et al. (2020) also reported a similar finding, where the city compost sourced from MSW lagged major plant nutrients. RDF Characterization Processed trommel rejects constitute cloth, rexine, leather, jute, paper, plastics, coir and other inert contributed to RDF. The fraction of inert was as high as 37.2% of the overall RDF mass and it mostly constituted glass and sand. The combined weight of sand and glass fragments contributed 73.5% of the total inert, while the rest was stone and small brickbats. The higher level of silicon associated with the presence of glass and sand yielded siloxane and triggered the possibility of kiln corrosion. A detailed RDF analysis report is enclosed in Table 2. The values explicitly portray the quality of RDF is moderately lower and higher salts concentration is extremely prevalent. With relatively lower NCV and such high salt concentration, the above specimen will certainly pose a corrosion threat to the kiln and shall be either neglected as kiln feed or can be utilized after dilution with Grade III RDF quality. Further, such high ash generation will also induct high transportation and landfill charges. Leachate Characterization The Malkaram leachate lake is the end result of prolonged, slow, and steady mixing of the legacy leachate through the existing fissure cracks in the sheath rock bottom profile. Apparently, the concentration of leachate is significantly lower due to the dilution. Samples were analyzed in triplicates and the mean value is tabulated here in Table 3. The metal concertation and rest of the parameter values are well within the secondary treatment influent range, except for TDS. Thus, a modular aerobic biological treatment unit such as moving bed biofilm bioreactor (MBBR) or membrane bioreactor (MBR) would be a well-suited pick. However, a reverse osmosis (RO) system needs to be installed to get rid of the high TDS content. The permeate of RO can be reused back into the system. Whereas, the reject can be converted into dried powder through forced evaporation mechanisms. The higher concentration of salts in RDF collaterally justifies the elevated TDS level in leachate. In a leachate impact assessment study performed by El-Salam and Abu-Zuid (2015) the reported BOD/COD ratio of 0.69 is greater than double the value of 0.301 reported in Table 3. Though the difference in both the values are quite high, it is relatable and justifiable by the huge age difference of the source waste. The primarily characterized data is of a fresh leachate generated from regular MSW, while the later one is from a decade old waste that barely has any unstabilized organic content. Groundwater Contamination The obvious reason for downward leachate infiltration and osmotic movement facilitates groundwater contamination. Both surface and subsurface water samples were collected within the dump yard and the buffer zone and analyzed using the standard methods. The results are portrayed in Table 4. The slightly alkaline pH of the borewell sample is an indication of the ongoing anaerobic process. The dissolved oxygen value of 3.5 mg/L further validates the correlation. Higher TDS and hardness values are self-indicative of elevated salt concentration in source waste. Eventually, the same interfered with the RDF quality. Positively in the case of all the parameters, a successive decrement in pollution concentration has been spotted from dump ground towards the buffer zone. In a similar study conducted by Singh et al. (2016) at Varanasi, Uttar Pradesh the reported concentration of the parameters is significantly higher than reported in Table 4. The basic reason behind variation is the dissimilarities of the local soil profile. The sandy and clay loam soil profile of Varanasi allows a greater rate of percolation and infiltration. While the bottom sheath rock profile at Jawahar Nagar permits the only a minute to little percolation rate. The difference in percolation rate is directly correlated to the concentration levels in this case. Contrarily, Kurakalva et al. (2016) have reported much-elevated pollutant concertation both in ground and surface water for a study conducted at the same site in 2016. The higher concentration is relatable to the fact of the non-closure of the open dump back then. Capping activity had at Jawahar Nagar gained its pace 2018 onwards and capping for the primary section of 70 acres got concluded only during mid of 2019. Due to the decrement in runoff and percolation, the quality of both surface and subsurface water has improved drastically. Impact Assessment The odor and groundwater contamination are two of the primary issues that triggered a massive public agitation initially. The root causes of both the issues are identified as rainwater percolation and anaerobic digestion respectively. Eventually, the completion of the capping process would resolve both the problems effectively. Other non-tangential impacts include nausea; headache; irritation of the eye, nasal cavity, and throat; diarrhoeal diseases; vector-borne disease, cattle toxicity etc. Scientific capping can easily cater as the wholesome solution for all (Cortellazzo et al., 2020). Yu et al. (2018) had performed an extensive study to comprehend the relativity of respiratory sickness and MSW borne air pollution. The study made a couple of dreadful revelations such as gases released due to the anaerobic digestion of MSW such as methane, hydrogen sulphide, and ammonia incur detrimental impact on Lysozyme and secretory immunoglobulin A (SIgA). While SO2 was reported as the lung capacity and functionality reducer. Further, a gender-specific study executed by the same research group revealed, air pollution impacts more severely on male children than the female and retards immune functions. Presently, the area of 351 acres has been developed as Asia’s one of the largest state of the art municipal solid waste processing and disposal facility by Ramky Enviro Engineers Limited. This ensured zero dumping and no further environmental interventions. As legal compliance, the facility monitors the quality of groundwater and ambient air quality in and around the facility on monthly basis to assure the biosafety. The variation in concentration of various monitoring parameters between 2012 to 2020 is summarized in Figure 2. The concentration of each of the parameters are showcased in ppm and a standard equipment error was settled at 3% for respirable dust sampler and multi-gas analyzer (Taheri et al., 2014). Despite all parameter values have gradually increased except for methane, the facility still managed to maintain them well under the regulatory limits. The decrement in methane concentration is directly correlated to the practice of aerobic composting and aeration-based secondary treatment that prevented the formation of the anaerobic atmosphere and henceforth methane generation. While for the rest of the parameters the increment in values is quite substantial and predictable due to the sudden escalation in MSW generation in the past decade in correlation with Gross domestic product (GDP) enhancement. The observed and interpreted impacts due to the elevated pollutant level are in-line with the georeferenced findings reported by Deshmukh and Aher (2016) based on a study conducted at Sangamner, Maharashtra. CONCLUSION The study critically analyzed and investigated every techno-environmental and socio-economic aspect correlated to open dumping. The bench-scale experimentation revealed the efficiency of the single liner scientific capping is fair enough to eliminate any further rainwater infiltration, however, it has no control over the generation of leachate due to the inherent moisture. Internal moisture related issue was anyhow compensated with pertinent compaction prior to dispose of the waste. Contrarily, both the products derived through the biomining process namely, compost and RDF lagged quality due to scantier nutrient content and higher salt and silicon content respectively. Besides, impact assessment studies concede the pollutant concentration in groundwater in and around the plant has drastically diminished post-July 2019 due to the partial completion of waste capping. It also abetted lowering the dust and odor issues relatively in the surrounding. ACKNOWLEDGMENT The authors would like to sincerely acknowledge GHMC, Hyderabad Integrated Municipal Solid Waste Limited, and Ramky Enviro Engineers Limited for enabling us to pursue the sample collection and other necessary onsite activities. Further, the authors would like to register profound acknowledgment to EPTRI for supporting us with the essential experimental facilities. REFERENCES Sharma, A., Gupta, A.K., Ganguly, R. (2018), Impact of open dumping of municipal solid waste on soil properties in mountainous region. Journal of Rock Mechanics and Geotechnical Engineering 10 725-739 (2018). https://doi.org/10.1016/j.jrmge.2017.12.009 Jayawardhana, Y., Kumarathilaka, P., Herath, I., Vithanage, M. (2016) Municipal Solid Waste Biochar for Prevention of Pollution from Landfill Leachate. In: Prasad, M.N.V., Shih, K. (eds) Environmental Materials and Waste. 117-148, Academic Press, United States. https://doi.org/10.1016/B978-0-12-803837-6.00006-8 Kaksonen, A. H., Boxall, N. J., Bohu, T., Usher, K., Morris, C., Wong, P. Y., & Cheng, K. Y. (2017). Recent Advances in Biomining and Microbial Characterisation. Solid State Phenomena, 262, 33–37. https://doi.org/10.4028/www.scientific.net/ssp.262.33 Chakrabarti, M., Dubey, A. Remediation Techniques, for Open Dump Sites, used for the Disposal of Municipal Solid Waste in India. Journal of Basic and Applied Engineering Research 2, 1510-1513 (2015). Jerez, C.A. (2017) Bioleaching and biomining for the industrial recovery of metals. In: Reference module in life sciences. Elsevier, Amsterdam, pp 1–14. ISBN: 978-0-12-809633-8. https://doi.org/10.1016/B978-0-12-809633-8.09185-8 Banerjee, I., Burrell, B., Reed, C., West, A.C., Banta, S. Metals and minerals as a biotechnology feedstock: engineering biomining microbiology for bioenergy applications. CurrOpinBiotechnol. 45, 144-155 (2017). https://doi.org/10.1016/j.copbio.2017.03.009 Sethurajan, M., van Hullebusch, E.D., Nancharaiah, Y.V. Biotechnology in the management and resource recovery from metal bearing solid wastes. Recent advances. J Environ Manage. 211, 138-153 (2018). https://doi.org/10.1016/j.jenvman.2018.01.035 Thakare, S., Nandi, S. Study on Potential of Gasification Technology for Municipal Solid Waste (MSW) in Pune City. Energy Procedia 90, 509-517 (2016). https://doi.org/10.1016/j.egypro.2016.11.218 Bhat, S.A., Singh, J., Singh, K., Vig, A.P. Genotoxicity monitoring of industrial wastes using plant bioassays and management through vermitechnology: A review. Agriculture and Natural Resources 51, 325-337 (2017). https://doi.org/10.1016/j.anres.2017.11.002 Berkun, M., Aras, E., Nemlioglu, S. Disposal of solid waste in Istanbul and along the Black Sea coast of Turkey. Waste Manag. 25, 847-55 (2005). https://doi.org/10.1016/j.wasman.2005.04.004 Scott, K. (1995) MICROFILTRATION. In: Scott, K. (eds) Handbook of Industrial Membranes, 373-429, Elsevier Science, https://doi.org/10.1016/B978-185617233-2/50010-6 Mir, I.S., Cheema, P.P.S., Singh, S.P. Implementation analysis of solid waste management in Ludhiana city of Punjab. Environmental Challenges 2, 100023 (2021). https://doi.org/10.1016/j.envc.2021.100023 Al-Ghouti, M.A., Khan, M., Nasser, M.S., Al-Saad, K., Heng, O.E. Recent advances and applications of municipal solid wastes bottom and fly ashes: Insights into sustainable management and conservation of resources. Environmental Technology & Innovation 21, 101267 (2021). https://doi.org/10.1016/j.eti.2020.101267 Venkiteela, L.K. Status and challenges of solid waste management in Tirupati city. Materials Today: Proceedings 33, 470-474 (2020). https://doi.org/10.1016/j.matpr.2020.05.044. Cortellazzo, G., Mandaglio, M.C., Busana, S. et al. A New Approach for the Design, Construction and Control of Compacted Mineral Liners of a MSW Landfill Capping. Int. J. of Geosynth. and Ground Eng. 6, 49 (2020). https://doi.org/10.1007/s40891-020-00234-x Ayilara, M.S., Olanrewaju, O.S., Babalola, O.O., Odeyemi, O. Waste Management through Composting: Challenges and Potentials. Sustainability 12, 4456 (2020). https://doi.org/10.3390/su12114456 Deshmukh, K.K., Aher, S.P. Assessment of the Impact of Municipal Solid Waste on Groundwater Quality near the Sangamner City using GIS Approach. Water Resour Manage 30, 2425–2443 (2016). https://doi.org/10.1007/s11269-016-1299-5 Singh, S., Raju, N.J., Gossel, W. et al. Assessment of pollution potential of leachate from the municipal solid waste disposal site and its impact on groundwater quality, Varanasi environs, India. Arab J Geosci 9, 131 (2016). https://doi.org/10.1007/s12517-015-2131-x Yu, Y., Yu, Z., Sun, P., Lin, B., Li, L., Wang, Z., Ma, R., Xiang, M., Li, H., Guo, S. Effects of ambient air pollution from municipal solid waste landfill on children's non-specific immunity and respiratory health. Environmental Pollution 236, 382-390 (2018). https://doi.org/10.1016/j.envpol.2017.12.094 El-Salam, M.M.A., Abu-Zuid, G.I. Impact of landfill leachate on the groundwater quality: A case study in Egypt. Journal of Advanced Research 6, 579-586 (2015). https://doi.org/10.1016/j.jare.2014.02.003 Kurakalva, R.M., Aradhi, K.K., Mallela, K.Y., Venkatayogi, S. Assessment of Groundwater Quality in and around the Jawaharnagar Municipal Solid Waste Dumping Site at Greater Hyderabad, Southern India. Procedia Environmental Sciences 35, 328-336 (2016). https://doi.org/10.1016/j.proenv.2016.07.013 Mehta, Y.D., Shastri, Y., Joseph, B. Economic analysis and life cycle impact assessment of municipal solid waste (MSW) disposal: A case study of Mumbai, India. Waste Management & Research 36, 1177-1189 (2018). https://doi.org/10.1177/0734242X18790354 Taheri, M., Gholamalifard, M., Ghazizade, M.J., Rahimoghli, S. Environmental impact assessment of municipal solid waste disposal site in Tabriz, Iran using rapid impact assessment matrix. Impact Assessment and Project Appraisal 32, 162-169 (2014). https://doi.org/110.1080/14615517.2014.896082 Ashootosh, M., Periyaswamy, L., Sunil, K., Hiroshan, H. Mining for recovery as an option for dumpsite rehabilitation: case study from Nagpur, India. Journal of Environmental Engineering and Science 15, 52-60 (2020). https://doi.org/10.1680/jenes.19.00021 Ashford, S.A., Visvanathan, C., Husain, N., Chomsurin, C. Design and construction of engineered municipal solid waste landfills in Thailand. Waste Management & Research 18, 462-470 (2000). https://doi.org/10.1177/0734242X0001800507 Mohan S., Joseph C.P. (2020) Biomining: An Innovative and Practical Solution for Reclamation of Open Dumpsite. In: Kalamdhad A. (eds) Recent Developments in Waste Management. Lecture Notes in Civil Engineering, vol 57. Springer, Singapore. https://doi.org/10.1007/978-981-15-0990-2_12

The Western Ghats, a range of ancient hills extends between 8° N and 21° N latitude, and 73° E and 77° E longitude(from the tip of peninsular India at Kanyakumari to Gujarat). The Western Ghats runs parallel to the west coast of India, covering approximately 160,000 sq. km, which constitutes less than 5% of India's geographical extent. Numerous streams originate in the Western Ghats, which drain millions of hectares, ensuring water and food security for 245 million people and hence are aptly known as the water tower of peninsular India(Ramachandra and Bharath, 2019; Bharath et al., 2021). The region is endowed with diverse ecological regions depending on altitude, latitude, rainfall, and soil characteristics. The Western Ghats are among the eight hottest hotspots of biodiversity and 36 global biodiversity hotspots with exceptional endemic flora and fauna. Natural forests of Western Ghats have been providing various goods and services and are endowed with species of 4,600+ flowering plants (38% endemics), 330 butterflies (11% endemics), 156 reptiles (62% endemics), 508 birds (4% endemics), 120 mammals (12% endemics), 289 fishes (41% endemics) and 135 amphibians (75% endemics). The Western Ghats, gifted with enormous natural resource potential, and the mandate of sustainable development based on the foundation of prudent management of ecosystems, is yet a reality. Various unplanned developmental programs, which are proclaimed to be functioning on sustainability principles, have only been disrupting the complex web of life, impacting ecosystems, and causing a decline in overall productivity, including four major sectors: forestry, fisheries, agriculture, and water (Ramachandra and Bharath, 2019).The prevalence of barren hilltops, conversion of perennial streams to intermittent or seasonal streams, frequent floods and droughts, changes in water quality, soil erosion and sedimentation, the decline of endemic flora, and fauna, etc. highlights the consequences of unplanned developmental activities with a huge loss to the regional economy during the last century. The development goals need to be ecologically, economically, and socially sustainable, which can be achieved through the conservation and prudent management of ecosystems. Sustainability implies the equilibrium between society, ecosystem integrity, and sustenance of natural resources. Water sustenance in streams and rivers depends on the integrity of the catchment (watershed), as vegetation helps in retarding the velocity of water by allowing impoundment and recharging of groundwater through infiltration (Ramachandra et al., 2020). As water moves in the terrestrial ecosystem, part of it is percolated (recharging groundwater resources and contributing to sub-surface flow during post-monsoon seasons), while another fraction gets back to the atmosphere through evaporation and transpiration. Forests with native vegetation act as a sponge by retaining and regulating water transfer between land and the atmosphere. The mechanism by which vegetation controls flow regime is dependent on various bio-physiographic characteristics, namely, type of vegetation, species composition, maturity, density, root density and depth, hydro-climatic condition, etc. Roots of vegetation help (i) in binding soil, ii) improve soil structure by enhancing the stability of aggregates, which provide habitat for diverse microfauna and flora, leading to higher porosity of the soil, thereby creating the conduit for infiltration through the soil. An undisturbed native forest has a consistent hydrologic regime with sustained flows during lean seasons. Native species of vegetation with the assemblage of diverse native species help in recharging the groundwater, mitigating floods, and other hydro-ecological processes (Ramachandra et al., 2020; Bharath et al., 2021). Hence, it necessitates safeguarding and maintaining native forest patches and restoring existing degraded lands to sustain the hydrological regime, which caters to biotic (ecological and societal) demands. A comparative assessment of people's livelihood with soil water properties and water availability in sub-catchments of four major river basins in the Western Ghats reveals that streams in catchments with > 60% vegetation of native species are perennial with higher soil moisture (Ramachandra et al., 2020). The higher soil moisture due to water availability during all seasons facilitates farming of commercial crops with higher economic returns to the farmers, unlike the farmers who face water crises during the lean season. In contrast, streams are intermittent (6-8 months of water) in catchments dominated by monoculture plantations and seasonal (4 months, monsoon period) in catchments with vegetation cover lower than 30%. The study highlights the need to maintain ecosystem integrity to sustain water. Also, lower instances of COVID 19 in villages with native forests emphasize ecosystems' role in maintaining the health of biota. The need to maintain native vegetation in the catchment and its potential to support people's livelihood with water availability at local and regional levels is evident from the revenue of Rs. Rs.2,74,658 ha-1 yr-1 (in villages with perennial streams and farmers growing cash crops or three crops a year due to water availability), Rs. 1,50,679 ha-1 yr-1 (in villages with intermittent streams) and Rs. 80000 ha-1 yr-1 (in villages with seasonal streams). Also, the crop yield (at least 1.5 to 1.8 times) is higher in agriculture fields due to efficient pollination with the prevalence of diverse pollinators in the vicinity of native forests. The study emphasizes the need for maintaining the natural flow regime and prudent management of watershed to i) sustain higher faunal diversity, ii) maintain the health of water body, and iii) sustain people's livelihood with higher revenues. Hence, the premium should be on conserving the forests with native species to sustain water and biotic diversity in the water bodies, vital for food security. There still exists a chance to restore the lost natural ecosystems through appropriate ecological restoration approaches, with location-specific conservation and management practices to ensure adequate and clean water for all. GDP (Gross Domestic Product), a measure of the current economic well-being of a population, based on the market exchange of material well-being, will indicate resource depletion/degradation only through a positive gain in the economy and will not represent the decline in these assets (wealth) at all. Thus, the existing GDP growth percentages used as yardsticks to measure the development and well-being of citizens in decision-making processes are substantially misleading, yet they are being used. The traditional national accounts need to include resource depletion or degradation due to developmental activities and climate change. The country should move toward adopting Green GDP by accounting for the environmental consequences of the growth in the conventional GDP, which entails monetizing the services provided by ecosystems, the degradation cost of ecosystems, and accounts for costs caused by climate change. The forest ecosystems are under severe threat due to anthropogenic pressures, which are mostly related to the GDP.The appraisal of forest ecosystem services and biodiversity can help clarify trade­-offs among conflicting environmental, social, and economic goals in the development and implementation of policies and to improve the management in order biodiversity.Natural capital accounting and valuation of ecosystem services reveal that forest ecosystems provide (i) provisioning services (timber, fuelwood, food, NTFP, medicines, genetic materials) of Rs 2,19,494 ha-1 yr-1, (ii) regulating services (global climate regulation - carbon sequestration, soil conservation, and soil fertility, water regulation and groundwater recharge, water purification, pollination, waste treatment, air filtration, local climate regulation) of Rs 3,31,216 ha-1 yr-1 and (iii) cultural services (aesthetic, spiritual, tourism and recreation, education and scientific research) of Rs.1,04,561 ha-1 yr-1. Total ecosystem supply value (TESV), an aggregation of provisioning, regulating, and cultural services, amounts to Rs. 6,56,172 ha-1 yr-1, and the Net Present Value (NPV) of one hectare of forests amounts to 16.88 million rupees ha-1. NPV helps in estimating ecological compensation while diverting forest lands for other purposes. The recovery of an ecosystem with respect to its health, integrity, and sustainability is evident from an initiative of planting (500 saplings of 49 native species) in a degraded landscape (dominated by invasive species) of two hectares in the early 1990s at the Indian Institute of Science campus (Ramachandra et al., 2016),and the region has now transformed into a mini forest with numerous benefits such as improvements in groundwater at 3-6 m (compared to 30-40 m in 1990), moderated microclimate (with lower temperature) and numerous fauna (including four families of Slender Loris). While confirming the linkages of hydrology, ecology, and biodiversity, the experiment advocates the need for integrated watershed approaches based on sound ecological and engineering protocols to sustain water and ensure adequate water for all. A well-known and successful model of integrated wetlands ecosystem (Secondary treatment plant integrated with constructed wetlands and algae pond) at Jakkur Lake in Bangalore (Ramachandra et al., 2018) provides insights into the optimal treatment of wastewater and mitigation of pollution. Complete removal of nutrients and chemical contaminants happens when partially treated sewage (secondary treated) passes through constructed wetlands and algae pond (sedimentation pond), undergoes bio-physical and chemical processes. The water in the lake is almost potable with minimal nutrients and microbial counts. This model has been functioning successfully for the last ten years after interventions to rejuvenate the lake. This system is one of the self-sustainable ways of lake management while benefitting all stakeholders - washing, fishing, irrigation, and local people. Wells in the buffer zone (500 m), now have higher water levels and are without any nutrients (nitrate). Groundwater quality assessment in 25 wells in the same region during 2005 (before the rejuvenation of Jakkur Lake) had higher nitrate values. Adopting this model ensures optimal sewage treatment at decentralized levels, and letting treated water to the lake also provides nutrient-free and clean groundwater. The Jal Shakti ministry,the Government of India, through Jal Jeevan Mission, has embarked on the noble and novel mission of providing tap water supply to all rural households and public institutions in villages such as schools, health centers, panchayat buildings, etc. The success of this program depends on the availability of water. The imminent threat of acute water scarcity due to climate changes with global warming necessitates implementing integrated watershed development (planting of native species in the watershed of water bodies), rainwater harvesting (rooftop harvesting at individual household levels, and retaining rainwater in rejuvenated lakes, which also helps in recharge of groundwater) and reuse of wastewater through treatment at decentralized levels (a model similar to Jakkur lake at Bangalore). These prudent management initiatives at decentralized levels throughout the country aid in achieving the goals of providing clean and adequate water to the local community.

Can Gio mangrove forest (CGM) is located downstream of Ho Chi Minh City (HCMC), situated between an estuarine system of Dong Nai - Sai Gon river and a part of Vam Co river. The CGM is the largest restored mangrove forest in Vietnam and the UNESCO’s Mangrove Biosphere Reserve. The CGM has been gradually facing to numeric challenges of global climate change, environmental degradation and socio-economic development for the last decades. To evaluate sediment quality in the CGM, we collected 13 cores to analyze for sediment grain size, organic matter content, and trace element concentration of Cd, Cr, Cu, Ni, Pb, Zn. Results showed that trace element concentrations ranged from uncontaminated (Cd, Cu, and Zn) to very minor contaminated (Cr, Ni, and Pb). The concentrations were gradually influenced by suspended particle size and the mangrove plants.ReferencesAnh M.T., Chi D.H., Vinh N.N., Loan T.T., Triet L.M., Slootenb K.B.-V., Tarradellas J., 2003. Micropollutants in the sediment of Sai Gon – Dong Nai rivers: Situation and ecological risks. Chimia International Journal for Chemistry, 57, 09(0009–4293), 537–541.Baruddin N.A., Shazili N.A., Pradit S., 2017. Sequential extraction analysis of heavy metals in relation to bioaccumulation in mangroves, Rhizophora mucronata from Kelantan delta, Malaysia. AACL Bioflux, 10(2), 172-181. Retrieved from www.bioflux.com/aacl.Bravard J.-P., Goichot M., Tronchere H., 2014. An assessment of sediment transport processes in the lower Mekong river based on deposit grain size, the CM technique and flow energy data. Geomorphology, 207, 174-189.Cang L.T., Thanh N.C. 2008. Importing and exporting sediment to and from mangrove forest at Dong Trang estuary, Can Gio district, Ho Chi Minh city. Science & Technology Development, 11(04), 12-18.Carignan J., Hild P., Mevelle G., Morel J., Yeghicheyan D., 2001. Routine analyses of trace elements in geological samples using flow injection and low-pressure on-line liquid chromatography coupled to ICP-MS: A study of geochemical reference materials BR, DR-N, UB-N, AN-G and GH. The Journal of Geo standard and Geoanalysis, 187-198.Carlson P.R., Yarbro L.A., Zimmermann C.F., Montgomery J.R., 1983. Pore water chemistry of an overwash mangrove island. Academy Symposium: Future of the Indian River System, 46(3/4), 239-249. https://www.jstor.org/stable/24320336.Chatterjee M., Canário J., Sarkar S.K., Branco V., Godhantaraman N., Bhattacharya B.D., Bhattacharya A., 2012. Biogeochemistry of mercury and methylmercury in sediment cores from Sundarban mangrove wetland, India—a UNESCO World Heritage Site. Environ Monit Assess, 184, 5239–5254.Claudia R., Huy N.V., 2004. Water allocation policies for the Dong Nai river basin in Viet Nam: An integrated perspective. EPTD Discussion Paper, 127, 01-52.Folk R.L., Ward W.C., 1957. Brazos River bar: A study in the significance of grain size parameters. Journal of Sedimentary Petrology, 27(1), 3-26.Furukawaa K., Wolanski E., Mueller H., 1997. Currents and sediment transport in mangrove forests. Estuarine, Coastal and Shelf Science, 44, 301-310.Hai H.Q., Tuyen N.N., 2011. Coastal Erosion of Can Gio district Ho Chi Minh City due to the global climate change. The journal of development of technology and science, 14, 17-28.HCM SO S.O., 2015. Annual statistic data in 2015 for HCM city. Ho Chi Minh city: Statistic office of HCM city.HCMC, 2017. Decision No. 3901 on approving the areas of forest and land in HCM city in 2016. Ho Chi Minh: The people's committee of HCM city.Herut B., Sandler A., 2006. Normalization methods for pollutants in marine sediments: review and recommendations for the Mediterranean. Haifa 31080: Israel Oceanographic & Limnological Research: IOLR Report H18/2006.Hong P.N., San H.T., 1993. Mangroves of Vietnam: Chapter VI Human impacts on the mangrove ecosystem. Bangkok 10501: IUCN - The International Union for Conservation of Nature, ISBN: 2-8317-0166-x.Hubner R., Astin K.B., Herbert R.J., 2009. Comparison of sediment quality guidelines (SQGs) for the assessment of metal contamination in marine and estuarine environments. Journal of Environmental Monitoring, 11, 713–722.IAEA, 2003. Collection and preparation of bottom sediment samples for analysis of radionuclides and trace elements. Vienna, Austria: International Atomic Energy Agency, IAEA-TECDOC-1360, ISBN 92–0–109003–X.Jingchun L., Chongling Y., Ruifeng Z., Haoliang L., Guangqiu Q., 2008. Speciation changes of Cd in mangrove (Kandelia Candel L.) rhizosphere sediments. Bull Environ Contam Toxicol, 231-236. Doi:10.1007/s00128-007-9351-z.Kalaivanan R., Jayaprakash M., Nethaji S., Arya V., Giridharan L., 2017. Geochemistry of Core Sediments from Tropical Mangrove Region of Tamil Nadu: Implications on Trace Metals. Journal of Earth Science & Climatic Change, ISSN: 2157-7617., 8(1.1000385), 1-10. Doi:10.4172/2157-7617.1000385.Kathiresan K., Saravanakumar K., Mullai P., 2014. Bioaccumulation of trace elements by Avicennia marina. Journal of Coastal Life Medicine, 2(11), 888-894.Kitazawa T., Nakagawa T., Hashimoto T., Tateishi M., 2006. Stratigraphy and optically stimulated luminescence (OSL) dating of a Quaternary sequence along the Dong Nai River, southern Vietnam. Journal of Asian Earth Sciences, 27, 788–804.Lacerda L.D., 1998. Trace metals of biogeochemistry and diffuse pollution in mangrove (M. Vannucci, Ed.) Mangrove ecosystem occassional papers (ISSN: 0919-1348), 2, 1-72.Laura H., Probsta A., Probsta J.L., Ulrich E., 2003. Heavy metal distribution in some French forest soils: evidence for atmospheric contamination. The Science of Total Environment, 195-210.Li R., Li R., Chai M., Shen X., Xu H., Qiu G., 2015. Heavy metal contamination and ecological risk in Futian mangrove forest sediment in Shenzhen Bay, South China. Marine Pollution Bulletin, 101, 448–456.Long E., Morgan L.G., 1990. The potential for biological effects of sediment-sorted contaminants tested in the national status and trends program. Seattle, Washington: NOAA Technical Memorandum NOS OMA 52.Long E.R., Field L.J., MacDonald D.D., 1998. Predicting toxicity in marine sediments with numerical sediment quality guidelines. Environmental Toxicology and Chemistry, 17, 714–727. http://onlinelibrary.wiley.com/doi/10.1002/etc.5620170428/abstract;jsessionid=C5264A1AD0.7ACCA9B4EF9A088BE2EDE9.f04t04Long E.R., MacDonald D.D., Smith S.L., Calder F.D., 1995. Incidence of adverse biological effects within ranges of chemical concentration in marine and estuarine sediments. Environmental management, 19, 81-97.Maiti S.K., Chowdhury A., 2013. Effects of Anthropogenic Pollution on Mangrove Biodiversity: A Review. Journal of Environmental Protection, 4, 1428-1434.Marchand C., Allenbach M., Lallier-Verges E., 2011. Relation between heavy metal distribution and organic matter cycling in mangrove sediments (Conception Bay, New Caledonia). Geoderma, Elsevier, 160 (3-4), 444-456.Mohd F.N., Nor R.H., 2010. Heavy metal concentrations in an important mangrove species, Sonneratia caseolaris, in Peninsular Malaysia. Environment Asia, 3, 50-53.Muller G., 1979. Schwermetalle in den Sedimenten des Rheins - Veränderungen seit 1971. Umschau, 778-783.Nam V.N., 2007. Restoration of Can Gio mangrove forest: Its structure and function in comparison between the ecosytems of plantion and nature mangrove forest. Workshop on the thesis between Germany and Vietnam.Nickerson N.H., Thibodeau F.R., 1985. Association between pore water sulfide concentrations and the distribution of mangroves. Biogeochemistry, 1, 183-192.Ong Che R.G., 1999. Concentration of 7 Heavy Metals in Sediments and Mangrove Root Samples from Mai Po, Hong Kong. Marine Pollution Bulletin, 39, 269-279.Passega R., 1957. Texture as characteristics of clastic deposition. Publisher: American Association of Petroleum Geologists.Passega R., 1964. Grain size representation by CM patterns as a geological tool. J Sediment Petrol, 34, 830–847.Phuoc V.L., An D.T., Cang L.T., Chung B.N., Tien N.V., 2010. Study the sediment dynamics in Can Gio mangrove forest (Nang Hai site, Ho Chi Minh city). Ho Chi Minh city: The final report of National University Ho Chi Minh city, No. B2009-18-36.Pumijumnong N., Danpradit S., 2016. Heavy metal accumulation in sediments and mangrove forest stems from Surat Thani province, Thailand. The Malaysian forester, 79(1&2), 212-228.QCVN43:2012/BTNMT, 2012. QCVN43:2012/BTNMT: National technical regulation on the sediment quality, Ha Noi: Ministry of natural resources and environment of Vietnam.Qiao S., Shi X., Fang X., Liu S., Kornkanitnan N., Gao J., Yu Y., 2015. Heavy metal and clay mineral analyses in the sediments of Upper Gulf of Thailand and their implications on sedimentary provenance and dispersion pattern. Journal of Asian Earth Sciences, 114, 488–496.Rollinson H. R., 1993. Using geochemical data for evaluation, presentation and interpretation. UK: Longman Group UK Limited ISBN-0-582-06701-4.Spalding M., Blasco F., Field C., 2010. World atlas of mangrove. Cambridge: Earthscan in UK and US, ISBN: 978-1-84407-657-4.Strady E., Dang V.B., Némery J., Guédron S., Dinh Q.T., Denis H., Nguyen P.D., 2016. Baseline seasonal investigation of nutrients and trace metals in surface waters and sediments along the Saigon River basin impacted by the megacity of HCM, Viet Nam. Environ Sci Pollut Res, 1-18. doi:10.1007/s11356-016-7660-7.Tam N.F., Wong Y.S., 1996. Retention and distribution of heavy metals in mangrove soils receiving wastewater. Environment pollution, 94(5), 283-291.Thomas N., Lucas R., Bunting P., Hardy A., Rosenqvist A., Simard M., 2017. Distribution and drivers of global mangrove forest change, 1996– 2010. PLoS ONE, 12(6): e0179302, 1-14. Doi:10.1371/journal.pone.0179302.Thuy H.T., Loan T.T., Vy N.N., 2007. Study on environmental geochemistry of heavy metals in urban canal sediments of Ho Chi Minh city. Science and Technology Development, 10(01), 1-9.Toan T.T., Bay N.T., 2006. A study on the tendency of accretion and erosion in Can Gio coastal zone. Vietnam-Japan estuary workshop, 184-194.Tri N.H., Hong P.N., Cuc L.T., 2000. Can Gio Mangrove Biosphere Reserve Ho Chi Minh city, Ha Noi, Viet Nam. Ha Noi: Hanoi University Publisher.Truong T.V., 2007. Planning for water source of Dong Nai river basin. Retrieved from Water Resources Planning: http://siwrp.org.vn/tin-tuc/quy-hoach-tai-nguyen-nuoc-luu-vuc-song-dong-nai_143.html.Tuan L.D., Oanh T.T., Thanh C.V., Quy N.D., 2002. Can Gio mangrove biosphere reserve. HCM city, Vietnam: Agriculture Publisher.Tue N.T., Quy T.D., Amono A., 2012. Historical profiles of trace element concentrations in Mangrove sediments from the Ba Lat estuary, Red river, Vietnam. Water, Air & Soil Pollution, ISSN 0049-6979, 223(3), 1315-1330.Twilley R., Chen R., Hargis T., 1992. Carbon sinks in mangroves and their implications to carbon budget of tropical coastal ecosystems. Water, Air & Soil pollution, Netherland, 64, 265-288.UN Environment Program, 2006. Methods for sediment sampling and analysis. Palermo (Sicily), Italy: United Nation Environment Program.UNESCO, 2000. List of Biosphere reserves approved by MAB committee belonging to UNESCO. Retrieved from United Nations, Educational, Scientific, Cultural Organization (UNESCO): http://www.unesco.org/new/en/natural-sciences/environment/ecological-sciences/biosphere-reserves/asia-and-the-pacific.Vandenberghe N., 1975. An evaluation of CM patterns for grain size studies of fine grained sediments. Sedimentology, 22, 615-622.Vinh B.T., Ichiro D., 2012. Erosion mechanism of cohesive river bank and bed of Soai Rap river (Ho Chi Minh city). J. Sci. of the Earth, 34(2), 153-161.Wang J., Du H., Xu Y., Chen K., Liang J., Ke H., Cai M., 2016. Environmental and Ecological Risk Assessment of Trace Metal Contamination in Mangrove Ecosystems. BioMed Research International, Article ID 2167053, 1-14. Doi:10.1155/2016/2167053.Wedepohl K.H., 1995. The composition of the continental crust. Geochimica et Cosmochimica Acta, 59(7), 1217-1232.Woodroffe C., Rogers K., McKee K., Lovelock C., Mendelssohn I., Saintilan N., 2016. Mangrove sedimentation and response to relative sea level rise. The Annual Review of Marine Science, 8, 243-266.Zhang J., Liu C.L., 2002. Riverine Composition and Estuarine Geochemistry of Particulate Metals in China-Weathering Features, Anthropogenic Impact and Chemical Fluxes. Estuarine, Coastal and Shelf Science, 54(6), 1051-1070.Zhang W., Feng H., Chang J., Qu J., Xie H., Yu L., 2009. Heavy metal contamination in surface sediments of Yangtze River intertidal zone: An assessment from different indexes. Environmental Pollution, 157, 1533-1543.Zheng W.-j., Xiao-yong C., Peng L., 1997. Accumulation and biological cycling of heavy metal elements in Rhizophora stylosa mangroves in Yingluo Bay, China. Marine ecology progress series, 159, 293-301.

AbstractSixty-seven (67) groundwater samples from different land use areas such as dumpsites, industrial, markets and residential all within Lagos, southwest Nigeria, were sampled and sent to ACME Laboratories, Ontario, Canada, for geochemical analysis to determine some essential and toxic elements using inductively coupled plasma-mass spectrometer method. The purpose was to establish baseline values for the geochemical composition of groundwater in some parts of Lagos as well as the health risk assessment. Based on essential elements, 83%, 80% and 100% of groundwater samples were deficient in Ca, Mg and Se, respectively, while 75%, 10%, 7% and 8% of samples can be categorised as soft, moderately hard, hard and very hard water, respectively. The soft water, as well as different deficiencies in water, had been linked to heart problems, impeded growth, fertility disorders and liver diseases. Concentrations of As, Cd, Cr, Pb, Ni and Fe were higher than recommended standards in 2.94%, 1.5%, 1.5%, 29.4%, 4.4% and 4.7% of groundwater samples, respectively. Groundwater in the study area can be classified between not contaminated (< 1) to very highly contaminated (CI > 5) based on the contamination index. Highly contaminated samples were within dumpsites and industrial areas. The land-use activities have a direct or indirect impact on groundwater quality. The apparent sources of groundwater pollutants include industrial discharge, effluents, leachates and municipal wastes. The result of total health risk index for both ingestion and dermal exposure to water showed values far > 1 for all the toxic elements and generally pose non-carcinogenic health risk hazards for child and adult population in the study area. THI for samples from residential, market, industrial and dumpsites showed mean values of (9.60 and 3.75), (14.17 and 5.37), (9.8 and 3.4) and 95.44 and 37.48) for child and adult population, respectively. The degree of contamination in groundwater showed the following trends: dumpsite > industrial > markets > residential in the study area.

This study aimed to evaluate the suitability of groundwater for drinking purposes and assess the associated human health risks for different age groups in a coastal province of Mekong Delta, Vietnam. Twenty groundwater samples were collected in Soc Trang Province, and various water quality parameters were analyzed. The data were employed to calculate entropy-weighted groundwater quality index (EWQI), principal component analysis (PCA), cluster analysis (CA), and non-carcinogenic and carcinogenic risks for adult and children health. The results revealed that groundwater in some locations, especially in GW19, was polluted by hardness, total dissolved solids, NH4+, Cl-, Fe, total coliform, and E. coli. In addition, 5 principal components from the PCA results could explain 84.5% of the total variation of groundwater quality, which also suggested that the potential groundwater pollution sources were geochemical processes, agricultural activities, domestic and industrial wastewater, seawater intrusion, and excessive nitrogen fertilizer application. The CA results showed that monitoring locations can be divided into 4 clusters based on their similarities in groundwater quality, and the most polluted group was found at cluster IV (GW19). The computed EWQI values ranged from 20.05 to 738.52, with approximately 45% of total samples classifying good to excellent water quality. The sampling points with undrinkable quality are mainly located in the northeast and center of the province. The ratio of children and adults under the threat of adverse health effects due to drinking groundwater contained non-carcinogenic substances (NH4+, NO2-, NO3-, Cd, Cu, F-, Mn, and As) ranged from 5 to 40%, and children had higher risks compared to adults. Additionally, the consumption of As-contaminated groundwater also poses carcinogenic risks for children, female and male adults ranging from 4.80×10-6 to 1.33×10-4. The findings of this study can provide helpful information for policymakers in the development of long-term water management strategies to protect community health.

AbstractThis study investigates the risk to contamination of groundwater in public water supply wells in the Koprivnica-Križevci county (northwest Croatia). Five physicochemical parameters were monitored in all groundwater samples from 2008 to 2017 to identify major differences between the wells, assess temporal variations and understand the capacity for rainfall to alter groundwater pollution loadings. Multivariate discriminant analysis showed statistically significant differences between the six sampled wells based on the analyzed parameters (Wilks' lambda: 0.001; F = 26.2; p < 0.0000). Principal component analysis revealed two significant factors, including factor 1 which explained 32.8% of the variance (suggesting that the quality of the groundwater was mainly controlled by nitrate) and factor 2, accounting for 16.2% of the total variance (which corresponded to KMnO4/oxidizability and to a lesser extent, pH). The time series data showed disparate trends, with nitrate concentrations increasing, whereas pH and KMnO4 decreased, while electrical conductivity and chloride levels remained stable. Although rainfall can impact groundwater pollution loadings through dilution processes in aquifers, the resulting fluctuations in physicochemical parameters are complicated by variations in rainfall events and local topography, as well as from climate change. Therefore, it is important to predict the contamination of groundwater quality in the future using machine learning algorithms using artificial neural network or similar methods. Multivariate statistical techniques are useful in verifying temporal and spatial variations caused by anthropogenic factors and natural processes linked to rainfall. The resulting identified risks to groundwater quality would provide the basis for further groundwater protection, particularly for decisions regarding permitted land use in recharge zones.

AbstractIn rapidly growing cities in the tropics, unregulated urban development presents a major risk to groundwater quality. Here, we assess the vulnerability of an unconfined aquifer of Quaternary sands in the Thiaroye area of Dakar (Senegal) to contamination using four GIS-based indices (DRASTIC, DRASTIC_N, SINTACS, SI). Our correlation of assessed vulnerability to observed impact is semi-quantitative, relating observed groundwater quality, based on nitrate concentrations and tryptophan-like fluorescence to vulnerability degrees (i.e. coincidence rates). We show that considerably more of the Thiaroye area has a “very high vulnerability” according to SI (36%) relative to DRASTIC (5%) and SINTACS (9%); “high vulnerability” is estimated using DRASTIC_N (100%), DRASTIC (66%) and SINTACS (69%). Single-parameter sensitivity tests show that groundwater depth, soil, topography, land use and redox parameters strongly influence assessments of groundwater vulnerability. Correlation with observed nitrate concentrations reveals aquifer vulnerability is better represented by SI (coincidence rates of 56%) relative to DRASTIC_N (43%), SINTACS (38%) and DRASTIC (34%). The underestimation of groundwater vulnerability in Dakar using DRASTIC, DRASTIC_N and SINTACS is attributed to their reliance on an assumed capacity of the unsaturated zone to attenuate surface or near-surface contaminant loading, which in the low-income (Thiaroye) area of Dakar is thin and affords limited protection. The inclusion of a land-use parameter in SI improves the characterization of groundwater vulnerability in this low-income, rapidly urbanizing area of Dakar.

Uncertainties in the contamination and salinization mechanisms of the freshwater lens (FWL) in the semi-arid coral-limestone aquifer of Delft Island, Sri Lanka threatens its water security. The processes governing the quality and distribution of the FWL were therefore investigated through recharge assessment and hydrochemical analysis. Potential groundwater recharge zones based on land classification and geology were first identified. A rootzone water balance model was then built, which revealed the spatiotemporal variability of potential groundwater recharge occurring rapidly during the wet season (October to January) and most abundantly on pasture land underlain by yellow and brown sand. Recharge also varied largely between dry and wet years. Where the water table was shallow, intense rainfall in wet years was seen to result in surface flooding. Geochemical modeling using PHREEQC combined with diagrams (Piper and Stiff) and scatter plots, including stable water isotopes, revealed the meteoric origin of groundwater with salinization mainly caused by seawater mixing and slight evaporation. Findings also suggest that salinization is driven by the island's low-lying nature (maximum elevation of 6 m above sea level), the low hydraulic heads (maximum of 3.7 m above sea level), the shallow depth of the marine water, the presence of lagoons in the center which are inferred to be in hydraulic continuity with the ocean, and to some extent by unregulated abstraction of groundwater through shallow hand-dug wells. We hypothesize about infiltration and percolation of saline water through the root zone during storm inundations near the coast, supported by the combined occurrence of high values of partial CO2 pressure, alkalinity and salinity in groundwater samples. Cation exchange showed indications of salinization of wells mostly in low lying areas (minimum Na/Cl value of 0.66), and freshening in areas near the coast with high potential groundwater recharge (maximum Na/Cl value of 1.04). Elevated nitrate concentrations (maximum of 2.55 mmol/L NO3-) in groundwater samples were observed. This suggests that anthropogenic contamination is further threatening the already scarce resource as well as coastal ecosystems that may be groundwater dependent.

In sub-Saharan Africa, land cover change, expansion of hydropower infrastructure, and increased flooding complicate country-level efforts to meet the Sustainable Development Goal target concerning access to safe water. The Water, Energy and Food (WEF) nexus approach recognises that addressing these complex challenges requires cross-sectoral analyses at multiple scales. Building on such an approach, our study examined the interrelationships between land cover change, dam-related flooding and access to safe water via a national-level spatial analysis with local case studies in Malawi and Ghana. Our assessment of the water–food interactions found that areas of overlap between water points and cropland increased from 2000 to 2020 for both countries at national scale, but overlap extent varied greatly depending on the land cover product used. Local-scale exploration of water point installation patterns in Zomba, Malawi confirmed this pattern, highlighting increasing non-governmental funding of borehole installation programmes. Our assessment of water–energy interactions found that flooding mediated by hydropower dams increased for the White Volta Basin in Ghana, thereby increasing inundation of groundwater points. Local-scale focus group discussions revealed flooding resulted in contaminated water sources and high risk of injury or drowning whilst fetching water. Overall, our study highlights how socio-economic drivers are bringing water points, flooding and cropland into closer proximity, requiring flood mitigation measures at water points and agro-chemical management to minimise potential water quality impacts. Given differences between land cover products, we recommend more robust integration of existing land cover products to better monitor these phenomena.

The menace of environmental pollution due to improper municipal solid waste management (MSWM) has been enduring the human world still it is growing due to enormous growth of industries in the developing countries. Currently 2.0 billion tonnes per year of MSW is generating. Solid Waste Management process includes the collection, conveyance, segregation, treatment and disposal. Various municipal Solid waste treatment (landfilling, incineration, open burning) processes which emits the hazardous Greenhouse gases &affects Environment and Human health. This study has made an attempt on collection of data about various process involved in treatment of Hyderabad Integrated Municipal Solid Waste Management (HIMSWM) done by Ramky group PvtLtd and its impact on air. During 2018 national cleanliness survey was conducted in that Hyderabad ranked first out of 4,203 cities in Solid Waste Management. GHMC, the Greater Hyderabad Municipal Corporation, is responsible for the city's Solid Waste Management function. Hyderabad ranks among the top 5 cities in India in Solid Waste generation. In these processes Landfilling is one of the major municipal solid wastes (MSW) disposal methods practiced all over the world. Although it is considered as the most cost-effective means of waste disposal, but there are poor management practices specially in developing countries like India are the major causes of environmental pollution. Recently several studies has been carried out for the better understanding of the effects of landfill pollution on human health as well on the environment. Toxic gas emissions from landfills like Methane, NOx, SO2, VOC’s, CO2, PM, HC, pose a serious threat to both the environment and human health. Some studies has shown that the toxic gases released from landfill sites are even responsible for the lung and heart diseases in humans beings. Landfills also generate a toxic soup known as leachate, formed when the waste is subjected to biological and physiochemical transformation process. Leachate is highly toxic and causes the land and groundwater pollution. This study focus the impact on air due to landfills, and the challenges faced in the current scenario, and the possible measures that can be taken to deal with the problem of municipal solid waste management treatment

A wide range of models and techniques are briefly reviewed within the context of the Thames nitrates study in which models were developed to assess impacts of agricultural practices on nitrate levels in the river system. Here a semi-distributed approach was adopted in which a series of component models was developed to simulate hydrological and chemical behaviour of the Thames River basin. These components included: ( a ) a daily hydrological model for the Thames basin, which included 17 tributary sub-catchments and several major aquifer systems. The model provided input flows such as tributaries, groundwater, surface runoff, effluent returns as well as abstraction flows; ( b ) a soil zone and aquifer model for calculating the nitrate concentrations of surface runoff and groundwater given a particular land-use and fertilizer application rate; ( c ) An integrated model of flow and water quality for the main river, which provided a mass balance along 22 reaches of the main river, allowed for denitrification processes and incorporated all inputs from the non-point sources derived by ( a ) and ( b ) above. Model results will be presented together with an assessment of the major problems of nitrate modelling and predictions, which occur within the hydrologically active soil zone.

In the modern socio-ecological and economic life of Ukraine, rural areas occupy a special place; they are an integral part of the agricultural sphere, because they are home to more than a third of the population of our country. These areas are characterized by an exceptional contribution to the formation of food security. Increasing the country’s export potential makes the development of rural areas one of the main priorities of Ukraine’s state policy, which aims to raise living standards of the rural population, increase the efficiency of the agro-industrial complex, improve the environment and improve the quality of life of peasants. However, prior to land reform, monitoring of agricultural land on former collective and state farms was conducted at the state level, and residential areas where the population grew for their own needs were never surveyed. And according to the population itself, no standards for the use of chemical pesticides and fertilizers have ever been observed. Many years of research conducted at the Institute of Agroecology and Nature Management of NAAS found that in the residential area of rural settlements drinking water is contaminated with nitrates, vegetable products — nitrates and heavy metals, which indicates the need for monitoring in the residential area. Modern ecological assessment of rural settlements remains relevant, unrealized and requires regular research, socio-ecological monitoring and scientific substantiation of their ecologically balanced development. Intensification of agricultural production, reduction of forests and forest belts, intensive plowing of lands, intensification of water and wind erosion processes, drainage of swamps, migration and reduction of the number of experienced rural population have led to degradation of Ukraine’s agrosphere. The analysis of modern strategies of development of rural territorial communities has shown that in none of them the ecological nature protection aspect is taken into account (at best, socio-economic one, and usually — just economic development). This indicates that community leaders are not properly trained to perform their current community development functions, taking into account environmental security and policies. The still low ecological culture and consciousness of the rural population of Ukraine inhibits the civilized development of rural areas and with it the quality of life of the population in these areas.