Journal articles on the topic 'Stream and groundwater salinity'
To see the other types of publications on this topic, follow the link: Stream and groundwater salinity.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Stream and groundwater salinity.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
McNeil, V. H., and M. E. Cox. "Defining the climatic signal in stream salinity trends using the Interdecadal Pacific Oscillation and its rate of change." Hydrology and Earth System Sciences 11, no. 4 (May 3, 2007): 1295–307. http://dx.doi.org/10.5194/hess-11-1295-2007.
Full textAbstract:
Abstract. The impact of landuse on stream salinity is currently difficult to separate from the effect of climate, as the decadal scale climatic cycles in groundwater and stream hydrology have similar wavelengths to the landuse pattern. These hydrological cycles determine the stream salinity through accumulation or release of salt in the landscape. Widespread patterns apparent in stream salinity are discussed, and a link is demonstrated between stream salinity, groundwater levels and global climatic indicators. The Interdecadal Pacific Oscillation (IPO) has previously been investigated as a contributory climatic indicator for hydrological and related time series in the Southern Hemisphere. This study presents an approach which explores the rate of change in the IPO, in addition to its value, to define an indicator for the climate component of ambient shallow groundwater levels and corresponding stream salinity. Composite time series of groundwater level and stream salinity are compiled using an extensive but irregular database covering a wide geographical area. These are modelled with respect to the IPO and its rate of change to derive control time series. A example is given of how a stream salinity trend changes when the decadal climatic influence is removed.
2
Bailey, Ryan T., Saman Tavakoli-Kivi, and Xiaolu Wei. "A salinity module for SWAT to simulate salt ion fate and transport at the watershed scale." Hydrology and Earth System Sciences 23, no. 7 (July 31, 2019): 3155–74. http://dx.doi.org/10.5194/hess-23-3155-2019.
Full textAbstract:
Abstract. Salinity is one of the most common water quality threats in river basins and irrigated regions worldwide. However, no available numerical models simulate all major processes affecting salt ion fate and transport at the watershed scale. This study presents a new salinity module for the SWAT model that simulates the fate and transport of eight major salt ions (SO42-, Ca2+, Mg2+, Na+, K+, Cl−, CO32-, HCO3-) in a watershed system. The module accounts for salt transport in surface runoff, soil percolation, lateral flow, groundwater, and streams, and equilibrium chemistry reactions in soil layers and the aquifer. The module consists of several new subroutines that are imbedded within the SWAT modelling code and one input file containing soil salinity and aquifer salinity data for the watershed. The model is applied to a 732 km2 salinity-impaired irrigated region within the Arkansas River Valley in southeastern Colorado and tested against root zone soil salinity, groundwater salt ion concentration, groundwater salt loadings to the river network, and in-stream salt ion concentration. The model can be a useful tool in simulating baseline salinity transport and investigating salinity best management practices in watersheds of varying spatial scales.
3
Bari, M. A., and K. R. J. Smettem. "A daily salt balance model for representing stream salinity generation process following land use change." Hydrology and Earth System Sciences Discussions 2, no. 4 (July 22, 2005): 1147–83. http://dx.doi.org/10.5194/hessd-2-1147-2005.
Full textAbstract:
Abstract. We developed a coupled salt and water balance model to represent the stream salinity generation process following land use changes. The conceptual model consists of three main components with five stores: (i) Dry, Wet and Subsurface Stores, (ii) saturated Groundwater Store and (iii) a transient Stream zone Store. The Dry and Wet Stores represent the salt and water movement in the unsaturated zone and also the near-stream dynamic saturated areas, responsible for the generation of salt flux associated with surface runoff and interflow. The unsaturated Subsurface Store represents the salt bulge and the salt fluxes. The Groundwater Store comes into play when the groundwater level is at or above the stream invert and quantifies the salt fluxes to the Stream zone Store. In the stream zone module, we consider a "free mixing" between the salt brought about by surface runoff, interflow and groundwater flow. Salt accumulation on the surface due to evaporation and its flushing by initial winter flow is also incorporated in the Stream zone Store. The salt balance model was calibrated sequentially following successful application of the water balance model. Initial salt stores were estimated from measured salt profile data. We incorporated two lumped parameters to represent the complex chemical processes like diffusion-dilution-dispersion and salt fluxes due to preferential flow. The model has performed very well in simulating stream salinity generation processes observed at Ernies and Lemon experimental catchments in south west of Western Australia. The simulated and observed stream salinity and salt loads compare very well throughout the study period. The model slightly over predicted annual stream salt load by 6.2% and 6.8%, with R2 of 0.95 and 0.96 for Ernies and Lemon catchment, respectively.
4
Bari, M. A., and K. R. J. Smettem. "A daily salt balance model for stream salinity generation processes following partial clearing from forest to pasture." Hydrology and Earth System Sciences 10, no. 4 (July 11, 2006): 519–34. http://dx.doi.org/10.5194/hess-10-519-2006.
Full textAbstract:
Abstract. We developed a coupled salt and water balance model to represent the stream salinity generation process following land use changes. The conceptual model consists of three main components with five stores: (i) Dry, Wet and Subsurface Stores, (ii) a saturated Groundwater Store and (iii) a transient Stream zone Store. The Dry and Wet Stores represent the salt and water movement in the unsaturated zone and also the near-stream dynamic saturated areas, responsible for the generation of salt flux associated with surface runoff and interflow. The unsaturated Subsurface Store represents the salt bulge and the salt fluxes. The Groundwater Store comes into play when the groundwater level is at or above the stream invert and quantifies the salt fluxes to the Stream zone Store. In the stream zone module, we consider a "free mixing" between the salt brought about by surface runoff, interflow and groundwater flow. Salt accumulation on the surface due to evaporation and its flushing by initial winter flow is also incorporated in the Stream zone Store. The salt balance model was calibrated sequentially following successful application of the water balance model. Initial salt stores were estimated from measured salt profile data. We incorporated two lumped parameters to represent the complex chemical processes like diffusion-dilution-dispersion and salt fluxes due to preferential flow. The model has performed very well in simulating stream salinity generation processes observed at Ernies and Lemon experimental catchments in south west of Western Australia. The simulated and observed stream salinity and salt loads compare very well throughout the study period with NSE of 0.7 and 0.4 for Ernies and Lemon catchment respectively. The model slightly over predicted annual stream salt load by 6.2% and 6.8%.
5
Dalal, R. C., R. Eberhard, T. Grantham, and D. G. Mayer. "Application of sustainability indicators, soil organic matter and electrical conductivity, to resource management in the northern grains region." Australian Journal of Experimental Agriculture 43, no. 3 (2003): 253. http://dx.doi.org/10.1071/ea00186.
Full textAbstract:
Sustainability is a multifaceted concept. It is expressed here as 'to ensure that the past and current management and use of natural resources does not diminish their capacity to meet economic, environmental, social and aesthetic needs and opportunities of the present and future generations'. Sustainability indicators can be used to monitor responses in condition and trend as a result of natural resource management. We report here 2 case studies that demonstrate the significance of sustainability indicators in discerning trends in land and water resources in the southern Brigalow (Acacia harpophylla) Belt, a major region of the Queensland Murray–Darling Basin. First, soil organic matter was used as a sustainability indicator of soil productivity, soil aggregation, and its association with soil sodicity since these soil attributes affect infiltration rates, runoff and drainage. The second study involved comparing the trends in stream salinity (electrical conductivity) over 35 years and sustainability indicators for a dominant Vertosol in a region used for cereal cropping. Groundwater level and electrical conductivity of a long-term monitoring bore in the Dalby–Chinchilla region, were also analysed to discern trends in salinity and association of the groundwater with soil and stream salinity. Soil organic matter declined exponentially as the cultivation period for cereal cropping increased. This resulted in a reduction in soil nitrogen supply, and lower grain protein and cereal grain yields. The associated effects were reduced soil aggregation and increased soil sodicity. Electrical conductivity of the soil as well as stream water showed weak but declining trends with time. Groundwater level from the long-term monitoring bore near the stream and groundwater salinity showed significantly declining trends over the 35 years sampling period. Groundwater salinity was similar to the Vertosol electrical conductivity at 240–300 cm depths, suggesting groundwater connectivity to the overlaying soil. Thus, use of sustainability indicators provided a strong association among the various attributes of the landscape. However, it is still a challenge to integrate the various sustainability indicators in a landscape context, integrated over space (spatial and geographical distribution), attributes (quality characteristics) and time (trend).
6
Gustafson, Chloe D., Kerry Key, Matthew R. Siegfried, J. Paul Winberry, Helen A. Fricker, Ryan A. Venturelli, and Alexander B. Michaud. "A dynamic saline groundwater system mapped beneath an Antarctic ice stream." Science 376, no. 6593 (May 6, 2022): 640–44. http://dx.doi.org/10.1126/science.abm3301.
Full textAbstract:
Antarctica’s fast-flowing ice streams drain the ice sheet, with their velocity modulated by subglacial water systems. Current knowledge of these water systems is limited to the shallow portions near the ice-bed interface, but hypothesized deeper groundwater could also influence ice streaming. Here, we use magnetotelluric and passive seismic data from Whillans Ice Stream, West Antarctica, to provide the first observations of deep sub–ice stream groundwater. Our data reveal a volume of groundwater within a >1-kilometer-thick sedimentary basin that is more than an order of magnitude larger than the known subglacial system. A vertical salinity gradient indicates exchange between paleo seawater at depth and contemporary basal meltwater above. Our results provide new constraints for subglacial water systems that affect ice streaming and subglacial biogeochemical processes.
7
McNeil, V. H., and M. E. Cox. "Defining the climatic signal in stream salinity trends using the Interdecadal Pacific Oscillation and its rate of change." Hydrology and Earth System Sciences Discussions 3, no. 5 (September 20, 2006): 2963–90. http://dx.doi.org/10.5194/hessd-3-2963-2006.
Full textAbstract:
Abstract. The impact of landuse on stream salinity is difficult to separate from decadal climatic variability, as the decadal scale climatic cycles in ground water and stream hydrology have similar wavelengths to the landuse pattern. These hydrological cycles determine the stream salinity through accumulation or release of salt in the landscape. The Interdecadal Pacific Oscillation (IPO) has been investigated before as an indicator of hydrological and related time series in the southern hemisphere. This study presents a new approach, which uses the rate of change in the IPO, rather than just its absolute value, to define an indicator for the climate component of ambient shallow groundwater tables and corresponding stream salinity. Representative time series of water table and stream salinity indicators are compiled, using an extensive but irregular database covering a very wide geographical area. These are modelled with respect to the IPO and its rate of change to derive climatic indicators. The effect of removing the decadal climatic influence from stream salinity trends is demonstrated.
8
Neal, C., and J. W. Kirchner. "Sodium and chloride levels in rainfall, mist, streamwater and groundwater at the Plynlimon catchments, mid-Wales: inferences on hydrological and chemical controls." Hydrology and Earth System Sciences 4, no. 2 (June 30, 2000): 295–310. http://dx.doi.org/10.5194/hess-4-295-2000.
Full textAbstract:
Abstract. Variations in sodium and chloride in atmospheric inputs (rainfall and mist), stream runoff and groundwater stores are documented for the upper Severn River (Afon Hafren and Afon Hore catchments), Plynlimon, mid-Wales. The results show five salient features. Sodium and chloride concentrations are highly variable and highly correlated in rainfall and mist. The sodium-chloride relationship in rainfall has a slope close to the sodium/chloride ratio in sea-water, and an intercept that is not significantly different from zero. This indicates that sea-salt is the dominant source of both sodium and chloride in rainfall, which would be expected given the maritime nature of the metrology. For mist, there is also a straight line with near-zero intercept, but with a slightly higher gradient than the sea-salt ratio, presumably due to small additional sodium inputs from other sources. There is an approximate input-output balance for both sodium and chloride, with the exception of one groundwater well, in which high chemical weathering results in an anomalous high Na/Cl ratio. Thus, atmospheric deposition is the dominant source of both sodium and chloride in groundwater and streamflow. The fluctuations in sodium and chloride concentrations in the streams and groundwaters are strongly damped compared to those in the rain and the mist, reflecting the storage and mixing of waters in the subsurface. On all timescales, from weeks to years, sodium fluctuations are more strongly damped than chloride fluctuations in streamflow. The additional damping of sodium is consistent with ion exchange buffering of sodium in the catchment soils. Sodium and chloride concentrations are linearly correlated in the streams and groundwaters, but the slope is almost universally less than the sea-salt ratio and there is a non-zero intercept. The Na/Cl ratio in streamflow and groundwater is higher than the sea-salt ratio when salinity is low and lower than the sea-salt ratio when salinity is high. This pattern of behaviour is again consistent with ion exchange buffering of sodium in the catchment soils. The core features of this study are two fold. Firstly, sodium and chloride concentrations are highly damped within the streams and groundwaters relative to the atmospheric input. Secondly, streamflow sodium and chloride respond in similar ways across the catchments, except for the added cation exchange damping of the sodium signal. These findings are remarkable given the heterogeneous nature of the catchments and the complexity of the chemical time series signals in the streams. Keywords: Sodium; chloride; rainfall; mist; stream water; groundwater; Plynlimon; Hafren; Hore; Tanllwyth; moorland; Sitka spruce; forest; cation exchange; fractal
9
Makover, Judah, David Hasson, Yunyan Huang, Raphael Semiat, and Hilla Shemer. "Electrochemical removal of nitrate from a Donnan dialysis waste stream." Water Science and Technology 80, no. 4 (August 15, 2019): 727–36. http://dx.doi.org/10.2166/wst.2019.314.
Full textAbstract:
Abstract The objective of this work was to investigate electrochemical removal of nitrate from a high salinity waste stream generated by Donnan dialysis. Donnan dialysis for nitrate removal is a promising technique. It produces a distinctive composition of a high salinity waste stream of NaCl or Na2SO4 that requires a viable disposal method. The waste stream has the full anionic composition of contaminated groundwater, but the only cation is sodium. Experiments were conducted in a batch system setup. A copper cathode was chosen over brass, aluminum and graphite cathodes. A dimensionally stable anode (DSA), Ti/PbO2, was selected over a Ti/Pt anode. Electrochemical denitrification of high salinity Donnan dialysis nitrate wastes was successfully achieved, with different behavior exhibited in high salinity NaCl solution than in high salinity Na2SO4 solution. NaCl inhibited nitrate removal at high salinities while Na2SO4 did not. The maximum removals after 4 h operation in the high salinity wastes were 69 and 87% for the NaCl and Na2SO4 solutions respectively.
10
Beverly, C., M. Bari, B. Christy, M. Hocking, and K. Smettem. "Predicted salinity impacts from land use change: comparison between rapid assessment approaches and a detailed modelling framework." Australian Journal of Experimental Agriculture 45, no. 11 (2005): 1453. http://dx.doi.org/10.1071/ea04192.
Full textAbstract:
This paper illustrates the hydrological limitations and underlying assumptions of 4 catchment modelling approaches representing different generic classes of predictive models. These models are commonly used to estimate the impacts of land use and management change on stream flow and salinity regimes within a target region. Three approaches are based on a simple conceptual framework that assumes a single layer groundwater aquifer and requires minimal information and calibration (Zhang-BC2C, CAT1D-BC2C and LUCICAT), whereas the fourth approach (CAT3D) adopts a fully distributed highly parameterised catchment model capable of simulating complex multi-layered groundwater aquifer systems. All models were applied to the Gardiner subcatchment within the Goulburn–Broken region of Victoria, identified as a National Action Plan for Salinity priority subcatchment. Current condition simulation results were compared with observed stream flow and groundwater hydrograph data. Results show that the simple frameworks predicted whole-of-catchment mean annual salt and water yield with minimum parameterisation. The fully distributed framework produced similar catchment-scale responses to the simple approaches, but required more intensive input data and solution times. However, the fully distributed framework provides finer temporal and spatial scale information within the catchment. The more detailed models (such as CAT3D) also have the predictive capacity to assess the within-catchment dynamics at a range of scales and account for landscape position and complex surface/groundwater interactions. This paper concludes that the simple frameworks are useful for judging the whole-of-catchment impacts of broad-scale land use change on catchment water yields and salinity and therefore provide valuable tools for community engagement. However, the within-catchment dynamics are not well represented and particular care must be taken when applying such models in those catchments where the interaction between groundwater and surface features result in saturated areas that are disconnected from streams. Adoption of a distributed groundwater modelling environment similar to that of CAT3D provides higher spatial resolution relative to the lumped broad scale groundwater glow system (GFS) based parameterisation adopted by the BC2C rapid assessment approaches. The developers of the BC2C model acknowledge that such models are currently limited to upland local and intermediate groundwater flow systems. Given that the majority of land salinisation is located in regions dominated by intermediate and regional groundwater systems, this tool is not well suited to adequately model regional processes. In contrast, the CAT3D distributed groundwater models are likely to be applicable across a range of scales and provide the capacity to assess the trade offs between salinity recharge and discharge intervention strategies. We conclude that more complex models (e.g. CAT3D) are needed to identify at the land management scale (paddock/farm) cost effective land use and land management changes within the catchment to improve catchment health.
11
Cartwright, Ian. "Implications of variations in stream specific conductivity for estimating baseflow using chemical mass balance and calibrated hydrograph techniques." Hydrology and Earth System Sciences 26, no. 1 (January 14, 2022): 183–95. http://dx.doi.org/10.5194/hess-26-183-2022.
Full textAbstract:
Abstract. Baseflow to rivers comprises regional groundwater and lower-salinity intermediate water stores such as interflow, soil water, and bank return flows. Chemical mass balance (CMB) calculations based on the specific conductivity (SC) of rivers potentially estimate the groundwater contribution to baseflow. This study discusses the application of the CMB approach in rivers from south-eastern Australia and assesses the feasibility of calibrating recursive digital filters (RDFs) and sliding minima (SM) techniques based on streamflow data to estimate groundwater inflows. The common strategy of assigning the SC of groundwater inflows based on the highest annual river SC may not always be valid due to the persistent presence of lower-salinity intermediate waters. Rather, using the river SC from low-flow periods during drought years may be more realistic. If that is the case, the estimated groundwater inflows may be lower than expected, which has implications for assessing contaminant transport and the impacts of near-river groundwater extraction. Probably due to long-term variations in the proportion of groundwater in baseflow, the RDF and SM techniques cannot generally be calibrated using the CMB results to estimate annual baseflow proportions. Thus, it is not possible to extend the estimates of groundwater inflows using those methods, although in some catchments reasonable estimates of groundwater inflows can be made from annual streamflows. Short-term variations in the composition of baseflow also lead to baseflow estimates made using the CMB method being far more irregular than expected. This study illustrates that estimating baseflow, especially groundwater inflows, is not straightforward.
12
Shalem, Yehuda, Yoseph Yechieli, Barak Herut, and Yishai Weinstein. "Aquifer Response to Estuarine Stream Dynamics." Water 11, no. 8 (August 13, 2019): 1678. http://dx.doi.org/10.3390/w11081678.
Full textAbstract:
While seawater intrusions are widely discussed, the salinization of coastal aquifers via narrow rivers is hardly documented. This study investigates groundwater dynamics in an aquifer next to an estuarine stream on the eastern Mediterranean coast. Groundwater levels and salinization patterns were examined as a response to dynamic changes in estuary water, both in low-and high-permeability aquifer units. In the high-permeability unit, the extent of salinization was relatively constant, reaching a distance of at least 80 m from the river, with no long-term changes in fresh-saline interface depth, indicating that the system is in a quasi-steady state. Groundwater salinity in the low-permeability unit showed frequent and large fluctuations (up to 36 and 22 at 5 and 20 m from the river, respectively). We suggest that the river may have a more immediate impact on a low-permeability than on a high-permeability aquifer. This is dependent on the history of seawater encroachments to the river, which are better preserved in the low-permeability unit, and on the hydrogeology of this unit, where sand lenses can serve as high-permeability conduits. However, this unit can efficiently prevent a large extent of salinization of the regional coastal aquifer by the estuary water.
13
Poulsen, David L., Craig T. Simmons, Corinne Le Galle La Salle, and Jim W. Cox. "Assessing catchment-scale spatial and temporal patterns of groundwater and stream salinity." Hydrogeology Journal 14, no. 7 (August 24, 2006): 1339–59. http://dx.doi.org/10.1007/s10040-006-0065-9.
Full text
14
Lymbery, A. J., R. G. Doupé, and N. E. Pettit. "Effects of salinisation on riparian plant communities in experimental catchments on the Collie River, Western Australia." Australian Journal of Botany 51, no. 6 (2003): 667. http://dx.doi.org/10.1071/bt02119.
Full textAbstract:
Although the salinisation of streams has long been recognised as one of Western Australia's most serious environmental and resource problems, there is very little published information on the effects of salinisation on riparian flora and fauna. We studied riparian vegetation in three experimental catchments on the Collie River in Western Australia. The catchments are situated within a 5-km area of state forest and are geologically and botanically similar, but differ in the extent of clearing, groundwater levels and stream salinity. In each catchment, transects were taken perpendicular to the direction of streamflow, and 4-m2 quadrats taken along each transect. Within each quadrat, soil salinity was measured, all plants were identified to species level and percentage cover estimated. The catchments differed significantly in soil salinity, with salinity being greatest in the most extensively cleared catchment and increasing towards the floor of the valley. Plant-species richness, species diversity and species composition were significantly related to soil salinity, both among catchments and among quadrats within the most extensively cleared catchment. Plant-species richness and diversity decreased with increasing soil salinity, an effect that may be partly due to a decline in perennial herb and shrub species. This may have an impact on other components of the riparian ecosystem.
15
Moore, C. L., B. R. Jenkins, A. L. Cowood, A. Nicholson, R. Muller, A. Wooldridge, W. Cook, et al. "Hydrogeological Landscapes framework: a biophysical approach to landscape characterisation and salinity hazard assessment." Soil Research 56, no. 1 (2018): 1. http://dx.doi.org/10.1071/sr16183.
Full textAbstract:
In Australia, salinity has the potential to affect up to 17million hectares of agricultural and pastoral land. For many degraded sites, biophysical hazards are often poorly understood and consequently poorly managed. Attempts to remediate areas affected by salinity have met with varying degrees of success. The New South Wales (NSW) Office of Environment and Heritage, NSW Department of Primary Industries, University of Canberra and Geoscience Australia have collaborated to develop a biophysical expert-based approach for the assessment and management of salinity within landscapes. The Hydrogeological Landscape (HGL) framework provides a structure for understanding how salinity manifests in the landscape, how differences in salinity are expressed across the landscape and how salinity may best be managed. The HGL framework merges the flow dynamics of the groundwater flow system with the landscape elements of the soil landscape or regolith landform approaches. This is the first approach to specifically address all three manifestations of salinity: land salinity, in-stream salt load and in-stream salt concentration. The HGL framework methodology recognises the interplay between surface and subsurface flow systems, as well as the capacity for water to interact with salt stores in the landscape, and identifies biophysical landscape characteristics (e.g. amount and type of vegetation cover, typical land use practice) that affect these interactions. The HGL framework is an expert system that integrates the spatial variability of landscape characteristics and salinity processes to produce a salinity hazard assessment for any given area.
16
Kalantari, Nasrollah, and S. S. Thigale. "Three-Fold Remedial Measures for Groundwater Protection: Case Study of the Khathkari Stream, Pune District, India." Water Science and Technology 24, no. 11 (December 1, 1991): 33–40. http://dx.doi.org/10.2166/wst.1991.0334.
Full textAbstract:
A vast tract in Maharashtra State of India, constituted of horizontally disposed basaltic flows of Cretaceous-Eocene age, falls in the semi-arid climatic zone characterised by low precipitation and high temperature and evaporation. Such areas are marked by the variety of calcretes including massive, honeycomb, nodular, and powdery types. These calcretes which owe their origin to both pedogenic and nonpedogenic processes, are responsible for imparting the salinity to the groundwater. An integrated approach, involving geological, hydrogeological and hydrochemical studies, has been employed for delineating the boundary of saline and fresh waters in the groundwater system and evaluating the variation in salinity in the area around the Khathkari stream (18 13’ to 18 18’ N latitudes, and 74 13’ to 74 22’E longitudes) in Pune district. The paper briefly presents the data collected during the course of the work and incorporates the three-fold remedial measures such as i) protecting fresh water that occurs at deeper depth, ii) improving the present quality of water and iii) suggesting an appropriate crop-pattern that can stand for present and improved quality of water.
17
Price, Jonathan S., Kern Ewing, Ming-ko Woo, and Kenneth A. Kershaw. "Vegetation patterns in James Bay coastal marshes. II. Effects of hydrology on salinity and vegetation." Canadian Journal of Botany 66, no. 12 (December 1, 1988): 2586–94. http://dx.doi.org/10.1139/b88-350.
Full textAbstract:
The vegetation of a coastal marsh in southern James Bay was examined in reference to the salinity and hydrological processes. Regional hydrologic influences related to the freshwater budget of James Bay reduce the local salinity so that the vegetation typifies that of a fresh to brackish marsh system, in contrast to the Hudson Bay salt marshes reported in the literature. Thus species that thrive in areas of higher salinity have only limited occurrence at the study site. Infrequent tidal inundation of low salinity bay water diminishes surface salinity, which is primarily controlled by the interaction of marsh hydrology with fossil salt diffusing upward from postglacial deposits. The soil water salinity increases with depth and distance inland. However, local hydrologic gradients near raised beach ridges and incised stream channels affect surface runoff and groundwater recharge and discharge, producing further distinct spatial variations in salinity. These processes thus control the distribution of saline water in the rooting zone and hence the patterns of vegetation.
18
Rivett, Michael O., Shona Symon, Lucas Jacobs, Limbikani C. Banda, Gift J. Wanangwa, Donald J. C. Robertson, Ibrahim Hassan, et al. "Paleo-Geohydrology of Lake Chilwa, Malawi is the Source of Localised Groundwater Salinity and Rural Water Supply Challenges." Applied Sciences 10, no. 19 (October 2, 2020): 6909. http://dx.doi.org/10.3390/app10196909.
Full textAbstract:
Meeting long-term rural community water supply needs requires diligent geohydrological conceptualisation. Study of Malawi’s Lake Chilwa Basin, including sampling of 330 water points in Phalombe District, enabled assessment of groundwater quality influence upon supply. The control of larger Lake Chilwa paleo-environments on current Basin groundwater quality is demonstrated. Lacustrine sediment deposition forming high-level deposits under open lake conditions and terrace deposits under open and closed lake conditions significantly control the groundwater major-ion quality and salinity now observed. Paleo-lake extent marks the transition between low-TDS (total dissolved solids) groundwater suitable for water supply at higher elevations and high-TDS brackish groundwater in areas overlain by lacustrine deposits closer to the current lake level. Low-TDS groundwater is limited to mid-to-low reach influent leakage of rivers incising terraces. Permeable fluvial deposits within the deeper paleo-river channel may possibly provide low-TDS water. The conceptual model, whereby paleo-lake controls groundwater salinity, provides science-based evidence to address policy to manage the significant water point functionality concerns quantified at the district and river basin scales. Targeting of the low-TDS groundwater alongside improved use of upland low-TDS stream/river sources with fewer, but larger capacity, and better maintained gravity-fed supply schemes are recommended. This study hence shows the value of paleo-geohydrology interpretation of the lake–groundwater system conceptualisation to inform Sustainable Development Goal 6 (SDG 6.5.1)—integrated water resources management policy for rural water supply.
19
Knapp, Melissa A., Naomi Geeraert, Kiho Kim, and Karen L. Knee. "Submarine Groundwater Discharge (SGD) to Coastal Waters of Saipan (Commonwealth of the Northern Mariana Islands, USA): Implications for Nitrogen Sources, Transport and Ecological Effects." Water 12, no. 11 (October 28, 2020): 3029. http://dx.doi.org/10.3390/w12113029.
Full textAbstract:
Seagrass meadows and coral reefs along the coast of Saipan, a US commonwealth in the Northern Pacific, have been declining since the 1940s, possibly due to nutrient loading. This study investigated whether submarine groundwater discharge (SGD) contributes to nutrient loading and supports primary production on Saipan’s coast. SGD can be an important source of freshwater, nutrients, and other pollutants to coastal waters, especially in oceanic islands without well-developed stream systems. Ra and Rn isotopes were used as natural tracers of SGD. Nitrate, phosphate, and ammonium concentrations, ancillary water quality parameters, δ15N and δ18O of dissolved nitrate, and δ15N of primary producer tissue were measured. Our results pointed to discharge of low-salinity groundwater containing elevated concentrations of sewage-derived N at specific locations along Saipan’s coast. High SGD areas had lower salinity and pH, higher dissolved inorganic nitrogen concentrations, and elevated primary producer δ15N, indicative of sewage nitrogen inputs. We estimated that SGD could support 730–6400 and 3000–15,000 mol C d−1 of primary production in Tanapag and Garapan Lagoons, respectively, or up to approximately 60% of primary production in Garapan Lagoon. Efforts to improve water quality, reduce nutrient loading, and preserve coastal ecosystems must account for groundwater, since our results demonstrate that it is an important pathway of nitrogen delivery.
20
Swinton, Mark W., Lawrence W. Eichler, Sandra A. Nierzwicki-Bauer, Jeremy L. Farrell, James W. Sutherland, Michael R. Kelly, and Charles W. Boylen. "Groundwater attenuation of summer stream temperatures favors deeper intrusion depths into Lake George, NY." Hydrology Research 48, no. 1 (February 1, 2016): 177–90. http://dx.doi.org/10.2166/nh.2016.188.
Full textAbstract:
Groundwater inputs to two major streams along the southern end of Lake George attenuate summer temperatures resulting in deeper lake intrusion depths relative to other major streams. Between late April and early October, East and West Brook baseflow water temperatures generally were cooler than other major streams by ∼4 °C in mid-summer. Historical data for West Brook confirmed that the trend occurred as far back as 1970. As a consequence of cooler spring and summer temperatures coupled with higher salinity, deeper lake intrusion from these streams was hypothesized based on density calculations. Warmer streams entered the lake as overflow through late spring while East and West Brook intruded into the lake at depth. Upon stratification, East and West Brook intrude at or below the metalimnion while other monitored streams generally intrude at or above the metalimnion; by mid-August/early September all streams intruded below the metalimnion. High-resolution profiler data identified the presence of underflow during a fall storm event in 2014. Deeper intrusion depths of East and West Brook would supply organics and oxygen to the Caldwell Sub-basin hypolimnion which can potentially have both negative and positive effects on hypolimnetic oxygen depletion.
21
Hunter, Jason M., Holger R. Maier, Matthew S. Gibbs, Eloise R. Foale, Naomi A. Grosvenor, Nathan P. Harders, and Tahali C. Kikuchi-Miller. "Framework for developing hybrid process-driven, artificial neural network and regression models for salinity prediction in river systems." Hydrology and Earth System Sciences 22, no. 5 (May 22, 2018): 2987–3006. http://dx.doi.org/10.5194/hess-22-2987-2018.
Full textAbstract:
Abstract. Salinity modelling in river systems is complicated by a number of processes, including in-stream salt transport and various mechanisms of saline accession that vary dynamically as a function of water level and flow, often at different temporal scales. Traditionally, salinity models in rivers have either been process- or data-driven. The primary problem with process-based models is that in many instances, not all of the underlying processes are fully understood or able to be represented mathematically. There are also often insufficient historical data to support model development. The major limitation of data-driven models, such as artificial neural networks (ANNs) in comparison, is that they provide limited system understanding and are generally not able to be used to inform management decisions targeting specific processes, as different processes are generally modelled implicitly. In order to overcome these limitations, a generic framework for developing hybrid process and data-driven models of salinity in river systems is introduced and applied in this paper. As part of the approach, the most suitable sub-models are developed for each sub-process affecting salinity at the location of interest based on consideration of model purpose, the degree of process understanding and data availability, which are then combined to form the hybrid model. The approach is applied to a 46 km reach of the Murray River in South Australia, which is affected by high levels of salinity. In this reach, the major processes affecting salinity include in-stream salt transport, accession of saline groundwater along the length of the reach and the flushing of three waterbodies in the floodplain during overbank flows of various magnitudes. Based on trade-offs between the degree of process understanding and data availability, a process-driven model is developed for in-stream salt transport, an ANN model is used to model saline groundwater accession and three linear regression models are used to account for the flushing of the different floodplain storages. The resulting hybrid model performs very well on approximately 3 years of daily validation data, with a Nash–Sutcliffe efficiency (NSE) of 0.89 and a root mean squared error (RMSE) of 12.62 mg L−1 (over a range from approximately 50 to 250 mg L−1). Each component of the hybrid model results in noticeable improvements in model performance corresponding to the range of flows for which they are developed. The predictive performance of the hybrid model is significantly better than that of a benchmark process-driven model (NSE = −0.14, RMSE = 41.10 mg L−1, Gbench index = 0.90) and slightly better than that of a benchmark data-driven (ANN) model (NSE = 0.83, RMSE = 15.93 mg L−1, Gbench index = 0.36). Apart from improved predictive performance, the hybrid model also has advantages over the ANN benchmark model in terms of increased capacity for improving system understanding and greater ability to support management decisions.
22
Dabral, S., B. Bhatt, J. P. Joshi, and N. Sharma. "Groundwater suitability recharge zones modelling – A GIS application." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (November 28, 2014): 347–53. http://dx.doi.org/10.5194/isprsarchives-xl-8-347-2014.
Full textAbstract:
Groundwater quality in Gujarat state is highly variable and due to multiplicity of factors viz. influenced by direct sea water encroachment, inherent sediment salinity, water logging, overexploitation leading to overall deterioration in ground water quality, coupled with domestic and industrial pollution etc. The groundwater scenario in the state is not very encouraging due to imbalance between recharge and groundwater exploitation. Further, the demand for water has increased manifold owing to agricultural, industrial and domestic requirement and this has led to water scarcity in many parts of the state, which is likely to become more severe in coming future due to both natural and manmade factors. Therefore, sustainable development of groundwater resource requires precise quantitative assessment based on reasonably valid scientific principles. Hence, delineation of groundwater potential zones (GWPZ), has acquired great significance. <br><br> The present study focuses on the integrated Geospatial and Multi-Criteria Decision Making (MCDM) techniques to determine the most important contributing factors that affect the groundwater resources and also to delineate the potential zones for groundwater recharge. The multiple thematic layers of influencing parameters viz. geology, geomorphology, soil, slope, drainage density and land use, weightages were assigned to the each factor according to their relative importance as per subject experts opinion owing to the natural setup of the region. The Analytical Hierarchy Process (AHP) was applied to these factors and potential recharge zones were identified. The study area for the assessment of groundwater recharge potential zones is Mahi-Narmada inter-stream region of Gujarat state. The study shows that around 28 % region has the excellent suitability of the ground water recharge.
23
Borg, H., G. L. Stoneman, and C. G. Ward. "The effect of logging and regeneration on groundwater, streamflow and stream salinity in the southern forest of Western Australia." Journal of Hydrology 99, no. 3-4 (May 1988): 253–70. http://dx.doi.org/10.1016/0022-1694(88)90052-2.
Full text
24
Anderson, Thomas A., Erick A. Bestland, Lesja Soloninka, Ilka Wallis, Edward W. Banks, and Markus Pichler. "A groundwater salinity hotspot and its connection to an intermittent stream identified by environmental tracers (Mt Lofty Ranges, South Australia)." Hydrogeology Journal 25, no. 8 (July 19, 2017): 2435–51. http://dx.doi.org/10.1007/s10040-017-1637-6.
Full text
25
Gevera, Patrick Kirita, Mark Cave, Kim Dowling, Peter Gikuma-Njuru, and Hassina Mouri. "Naturally Occurring Potentially Harmful Elements in Groundwater in Makueni County, South-Eastern Kenya: Effects on Drinking Water Quality and Agriculture." Geosciences 10, no. 2 (February 6, 2020): 62. http://dx.doi.org/10.3390/geosciences10020062.
Full textAbstract:
Makueni County is located in the semi-arid south-eastern Kenya region characterized by unreliable rainfall and limited surface water resources. This necessitates a high reliance on groundwater for domestic and agricultural use. In this paper, we report on the physico-chemical characteristics of 20 drinking water sources (boreholes, shallow wells, streams, and tap water) collected during the dry season (November 2018), the geochemical processes controlling their composition, and their suitability for drinking water and irrigation. Of all the physico-chemical parameters analysed, the concentrations of total dissolved solids, hardness, electrical conductivity, magnesium, calcium, chloride, and fluoride exceeded the permissible drinking water limits set by both the World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) in up to 55% of the samples. The dominant ions reflect the high salinity in the water that ranged from very high to extreme in up to 50% of samples. The northern region shows the highest concentrations of the dominant parameters. The water type is predominantly Ca-Mg-HCO3 with a trend to Ca-Mg-Cl-SO4. Rock weathering and evaporation are suggested to be the primary controls of groundwater geochemical characteristics. High salinity and fluoride, which are associated with reported undesirable taste and gastrointestinal upsets, as well as cases of dental fluorosis are some of the effects of consuming groundwater in the region. These two parameters can be attributed to the weathering of biotite gneisses, granitoid gneisses, migmatites, and basaltic rocks that occur in the area. The high salinity and alkalinity of most of the samples analysed, renders the water unsuitable for irrigation in the study area.
26
Dowling, AJ, and EA Gardner. "Spatial variation in salinity of some alluvial aquifers in central Queensland - a steady state analysis." Soil Research 26, no. 4 (1988): 583. http://dx.doi.org/10.1071/sr9880583.
Full textAbstract:
This paper reports on the spatial variation of salinity in the alluvial groundwaters of the Callide Valley, central Queensland. The spatial distribution of salinity in this area is very complex with substantial variation occumng over small (< 1 km) and large (> 10 km) distances. This complexity has been attributed to variable leakage of highly saline water into the alluvium from adjacent hard rock aquifers. A simple but elegant steady-state dimensionless analysis is introduced to clearly establish if salt additions or subtractions are occurring in the alluvial groundwaters. By using ions not normally complicated by precipitation reactions (sodium and chloride), our analyses show that solutes are conserved, with excellent agreement between the measured data and theory. This result strongly supports a hypothesis of progressive concentration of a localized source of salt, introduced near the headwaters, with increasing distance down discrete alluvium-stream valleys. We conclude our paper with a caution on the delayed effects of distributed salt import into alluvial aquifers with large solute response times.
27
Jury, Mark R. "Turks and Caicos Islands Climate and Its Impacts." Earth Interactions 17, no. 18 (September 1, 2013): 1–20. http://dx.doi.org/10.1175/2012ei000490.1.
Full textAbstract:
Abstract The Turks and Caicos Islands (TCI) climate is described using mesoscale ocean and atmosphere datasets with a focus on thermodynamic versus kinematic controls, the influence of the nearby island of Hispaniola, and factors affecting early colonization and fluctuations of marine resources. The key findings include the following: trade winds accelerate to 7 m s−1 north of Hispaniola and enhance anticyclonic subsidence; there is a dry-south/wet-north pattern of rainfall that opposes surface temperature and salinity fields; ocean currents near TCI are northwestward but there is a counterclockwise gyre near Haiti that guided colonization; conch catch increases when trade winds strengthen and SST declines; TCI's dry climate limits groundwater resources, food production, and population density; and Caicos Island sheds a wind wake that boosts SST and local convection, as evident in Quick Scatterometer (QuikSCAT) observations and operational model products. Further studies of small island climates will benefit from an ever-increasing stream of mesoscale datasets.
28
Creegan, Emily F., Robert Flynn, Greg Torell, Catherine E. Brewer, Dawn VanLeeuwen, Ram N. Acharya, Richard J. Heerema, and Murali Darapuneni. "Pecan (Carya illinoinensis) and Dairy Waste Stream Utilization: Properties and Economics of On-Farm Windrow Systems." Sustainability 14, no. 5 (February 23, 2022): 2550. http://dx.doi.org/10.3390/su14052550.
Full textAbstract:
Improper management of organic waste can lead to unnecessary carbon dioxide and methane emissions, and groundwater contamination. In this study, organic waste materials from two of New Mexico’s (U.S.A.) top agricultural industries, pecan (Carya illinoinensis) and dairy cattle dairy manure, were used to evaluate the feasibility of an on-farm compost program. Pecan woody residues (P) served as the primary carbon source; regional cattle dairy manure (M) served as the primary nitrogen source. Additional (A) inputs from a compost consulting company (PM/A) and green waste from community landscaping and on-farm harvested legumes (PMG/A) were employed, both of which required additional labor and material inputs. Finished composts were analyzed for selected macro, secondary and micronutrients, pH, sodium adsorption ratio (SAR), electrical conductivity (EC), total carbon (TC) and organic matter (OM) content, bulk density (bd), and microbial biomass. The PM alone treatment showed similar or significantly higher amounts of macro, secondary and micronutrients compared to the PM/A and PMG/A treatments. Total microbial biomass and total salinity were highest for the PM treatment. The total cost of the PM treatment was around 1/6 of the cost of the lowest-cost addition compost production scheme, indicating that simpler, lower-input production methods may be more advantageous for on-farm compost program development.
29
Tyshchenko, Oles, and Yurii Tyshchenko. "Assessment of potential impact of career drainage on surface water during planned development of Bilanivo iron ore deposit." Ukrainian journal of remote sensing, no. 12 (May 11, 2017): 67–71. http://dx.doi.org/10.36023/ujrs.2017.12.97.
Full textAbstract:
Based on the chemical composition and groundwater reserves by balance calculations was revealed that discharges water drainage career at planned development of Bilanivo iron ore deposits in the Dniprodzerginsky reservoir won’t result in signifi cant environmental impacts. Other possible scenarios of discharges of discharge water will associated with significant changes in salinity of streams (in Psel river — twice growth, in Rud’ka river — 12 growth) and should be viewed as unacceptable. The work should be accompanied by regular hydrogeological, hydrochemical monitoring and remote sensing (aerospace monitoring).
30
Kolanuvada, Srinivasa Raju, and Sivkumar S. "Assessing Adverse Impacts of Aquaculture Activities on Groundwater Quality in Ponneri Taluk of Tiruvallur District, Tamilnadu using Drinking Water Quality Index." Research Journal of Chemistry and Environment 27, no. 2 (January 15, 2023): 73–80. http://dx.doi.org/10.25303/2702rjce073080.
Full textAbstract:
Tamilnadu is a State that is deprived of perennial water sources like major rivers and streams. Agricultural activities in Tamilnadu are mainly dependent on seasonal rainfall and ground water. The shortages of water resources drive many coastal farmers to convert their fertile agricultural lands to aquaculture. Groundwater suitability for human consumption is determined by its physical, chemical and bacteriological properties. Irrational conversion of agricultural lands to aquaculture is found to be unsustainable leading to wastage of sparse natural resource fertile land and groundwater. The aquaculture practices started very extensively since year 2012 where fertile agriculture land, land with scrub and wasteland area have been converted for the aquaculture ponds. The use of temporal remote sensing helps in understanding the patterns of land use conversion from agricultural practice to aquaculture. In addition, indiscriminate use of fertilizers and chemicals in aquaculture farming has led to soil salinization and ground water pollution in many parts of study area. Use of salinity indices was tried in identification of salinity levels in lands in and around the current and abandoned aquaculture ponds. The study indicates that the use of Remote Sensing and GIS has helped in identification of landuse conversion and its adverse effects on characteristics of land due to extensive aquaculture activities in Ponneri Taluk of Tamilnadu. Using satellite data of Landsat OLI 8 (2015), IRS LISS IV, Sentinel II 2017, the changes have been estimated. The water quality parameters include pH, TDS, cations such as Ca, Mg, Na and K, anions such as Cl, SO4, HCO3, NO3 and PO4. Surface and groundwater quality results are cross-checked at the field areas which clearly indicate that almost entire Ponneri Taluk groundwater is unsuitable for drinking purposes. The classification for drinking water is obtained by DWQI. The piper plot has been studied by the geochemistry methods.
31
Kumar, N., A. A. Mahessar, S. A. Memon, K. Ansari, and A. L. Qureshi. "Impact Assessment of Groundwater Quality using WQI and Geospatial tools: A Case Study of Islamkot, Tharparkar, Pakistan." Engineering, Technology & Applied Science Research 10, no. 1 (February 3, 2020): 5288–94. http://dx.doi.org/10.48084/etasr.3289.
Full textAbstract:
Groundwater is the only source of fresh water in the Thar Desert which is located in an arid region of Pakistan with dense population and spreads over 19,638km2. Low rainfall, low groundwater recharge, high evaporation and absence of perennial streams are the general reasons for water scarcity. Being the single water source for drinking, domestic and industrial uses, and livestock activities, this source is highly overexploited. Realizing the gravity of the situation, this paper presents a groundwater quality evaluation of Islamkot, Tharparkar, using Water Quality Index (WQI) and Geospatial tools. 40 samples were collected from dug wells. The TDS of 28 samples was found higher than 3000mg/L and 12 samples ranged from 1500 to 3000mg/L. Many (28) samples were not further analyzed due to their very high TDS which made the water unfit for drinking. Twelve samples with TDS ranging from 1500 to 3000 mg/L were further analyzed. The analyzed results revealed the average values of pH, EC, TDS, salinity, chloride, total alkalinity, fluoride, and arsenic. The results did not meet NEQS and WHO guidelines. Pearson correlation analysis was conducted among parameters. Further, groundwater quality was assessed by WQI and indicated that water quality varied from very poor to unsuitable for drinking. The consumption of polluted groundwater has been the main cause of prevalent waterborne diseases and poses a very high risk for public health
32
Currie, Dougal, Tariq Laattoe, Glen Walker, Juliette Woods, Tony Smith, and Kittiya Bushaway. "Modelling Groundwater Returns to Streams From Irrigation Areas with Perched Water Tables." Water 12, no. 4 (March 27, 2020): 956. http://dx.doi.org/10.3390/w12040956.
Full textAbstract:
Quantifying the magnitude and timing of groundwater returns to streams from irrigation is important for the management of natural resources in irrigation districts where the quantity or quality of surface water can be affected. Deep vadose zones and perched water tables can complicate the modelling of these fluxes, and model outputs may be biased if these factors are misrepresented or ignored. This study was undertaken in the Murray Basin in southern Australia to develop and test an integrated modelling method that links irrigation activity to surface water impacts by accounting for all key hydrological processes, including perching and vadose zone transmission. The method incorporates an agronomic water balance to simulate root zone processes, semi-analytical transfer functions to simulate the deeper vadose zone, and an existing numerical groundwater model to simulate irrigation returns to the Murray River and inform the management of river salinity. The integrated modelling can be calibrated by various means, depending on context, and has been shown to be beneficial for management purposes without introducing an unnecessary level of complexity to traditional modelling workflows. Its applicability to other irrigation settings is discussed.
33
Halse, S. A., J. K. Ruprecht, and A. M. Pinder. "Salinisation and prospects for biodiversity in rivers and wetlands of south-west Western Australia." Australian Journal of Botany 51, no. 6 (2003): 673. http://dx.doi.org/10.1071/bt02113.
Full textAbstract:
Saline water was common in south-west Western Australian aquatic systems prior to land-clearing because most streams and wetlands were ephemeral and evapo-concentrated as they dried, and there were high concentrations of stored salt in groundwater and soil profiles. Nevertheless, a 1998 review of salinity trends in rivers of south-west Western Australia showed that 20-fold increases in salinity concentrations had occurred since clearing in the medium-rainfall zone (300–700 mm). More recent data confirm these trends and show that elevated salinities have already caused substantial changes to the biological communities of aquatic ecosystems. Further substantial changes will occur, despite the flora and fauna of the south-west being comparatively well adapted to the presence of salinity in the landscape. Up to one-third of wetland and river invertebrate species, large numbers of plants and a substantial proportion of the waterbird fauna will disappear from the wheatbelt, a region that has high biodiversity value and endemism. Increased salinities are not the only threat associated with salinisation: increased water volumes, longer periods of inundation and more widespread acidity are also likely to be detrimental to the biota.
34
Walker, Glen R., Avril C. Horne, Quan J. Wang, and Rob Rendell. "Assessing the Impact of Irrigation Efficiency Projects on Return Flows in the South-Eastern Murray–Darling Basin, Australia." Water 13, no. 10 (May 14, 2021): 1366. http://dx.doi.org/10.3390/w13101366.
Full textAbstract:
Improving irrigation efficiency (IE) is an approach used globally to help meet competing demands for water and facilitate reallocation of water between sectors. In the Murray–Darling Basin in Australia, the Australian government has invested heavily in IE projects to recover water for the environment. However, this approach has been seriously questioned, out of concerns that improved IE would reduce irrigation return flows to rivers and therefore offset water recovery. In this study, we use a water balance model to assess the impact of the IE projects on return flows and highlight sensitivities and uncertainties. The model enables the impact on return flows to be assessed on specific IE projects and regional characteristics. Overall, reductions in return flows are estimated to be less than 20% of the total proposed IE savings. The history of IE in the southern MDB has meant that most of the current reductions are in ground return flows. Our estimate is much lower than two previous studies, mainly due to different assumptions being used on groundwater connectivity between irrigation areas and major streams. While the IE projects significantly reduce seepage to groundwater (with off-farm and on-farm projects reducing seepage by 19% and 53% of total savings respectively), not all seepage reductions will translate to a reduction in ground return flows to rivers. A lower estimate is consistent with existing monitoring and groundwater modeling studies. In this paper, the study results are discussed in a broader context of impacts of IE projects on volumes and salinity of streams and groundwater resources.
35
Vervoort, R. W., M. Silburn, and M. Kirby. "Near surface water balance in the Northern Murray-Darling Basin." Water Science and Technology 48, no. 7 (October 1, 2003): 207–14. http://dx.doi.org/10.2166/wst.2003.0442.
Full textAbstract:
The water balance allows the calculation of deep drainage from other components of the hydrological cycle. Deep drainage has been linked to outbreaks of dryland and irrigated salinity. Until recently, deep drainage was not considered to be an issue on the alluvial plains of the Northern Murray-Darling Basin. Recent simulation studies and calculations using the water balance suggest that substantial deep drainage occurs under irrigated agriculture. However, these estimates have large uncertainties due to possible errors in measurement, calculation and due to spatial variability. On a catchment scale the relative area under a certain land use as well as the connection to local groundwater and the influence of anomalies such as prior streams needs to be considered. This paper discusses the current state of knowledge on the water balance in the Northern Murray-Darling Basin and highlights the need for a concentrated effort to measure all the components of the water balance in this area, as well as the effect on shallow groundwater quality and levels.
36
Jolly, ID, GR Walker, and KA Narayan. "Floodwater recharge processes in the Chowilla Anabranch system, South Australia." Soil Research 32, no. 3 (1994): 417. http://dx.doi.org/10.1071/sr9940417.
Full textAbstract:
We report the results of a study into the interaction between floodwaters and an unconfined alluvial aquifer in the Chowilla anabranch system of the River Murray during a large flood. Data on watertable elevation, groundwater chemistry and unsaturated zone salt storage were collected before, during and after a flood in 1990 which inundated all but the very highest points of the floodplain. These data, combined with analytical modelling of the watertable behaviour throughout the flood, led us to conclude that diffuse vertical recharge of floodwater to the unsaturated zone is of little importance. As a consequence, only limited teaching of salt from this zone to the groundwater occurs. This appears to be due to a reduction in the infiltration capacity of the sodic clay surface soils of the floodplain which disperse and swell when wetted with the low salinity floodwater. This suggests that the unsaturated zone is not the major source of salt which enters the River Murray following floods. However, from previous studies it is clear that the floodplain is an important source of saline groundwater which is added to the river following floods. An alternative hypothesis to explain the observed salt accessions is that areas of the floodplain where the Coonambidgal Clay is thin or absent are zones of localized recharge which cause displacement of in situ groundwater into the floodplain streams. This hypothesis should be tested in further work.
37
Neal, C., and P. Shand. "Spring and surface water quality of the Cyprus ophiolites." Hydrology and Earth System Sciences 6, no. 5 (October 31, 2002): 797–817. http://dx.doi.org/10.5194/hess-6-797-2002.
Full textAbstract:
Abstract. A survey of surface, spring and borehole waters associated with the ophiolite rocks of Cyprus shows five broad water types (1) Mg-HCO3, (2) Na-SO4-Cl-HCO3, (3) Na-Ca-Cl-SO4-OH-CO3, (4) Na-Cl-SO4 and (5) Ca-SO4. The waters represent a progression in chemical reactivity from surface waters that evolve within a groundwater setting due to hydrolysis of the basic/ultrabasic rock as modified by CO2-weathering. An increase in salinity is also observed which is due to mixing with a saline end-member (modified sea-water) and dissolution of gypsum/anhydrite. In some cases, the waters have pH values greater than 11. Such high values are associated with low temperature serpentinisation reactions. The system is a net sink for CO2. This feature is related not only to the hydrolysis of the primary minerals in the rock, but also to CaCO3 or Ca-Mg-CO3 solubility controls. Under hyperalkaline conditions, virtually all the carbon dioxide is lost from the water due to the sufficiently high calcium levels and carbonate buffering is then insignificant. Calcium sulphate solubility controls may also be operative when calcium and sulphate concentrations are particularly high. Keywords: Cyprus, Troodos, ophiolite, serpentinisation, spring, stream, water quality, bromide, iodine, boron, trace elements, hyperalkaline.
38
Saowanee, Wijitkosum. "Fuzzy AHP for drought risk assessment in Lam Ta Kong watershed, the north-eastern region of Thailand." Soil and Water Research 13, No. 4 (October 18, 2018): 218–25. http://dx.doi.org/10.17221/158/2017-swr.
Full textAbstract:
Droughts occur from a combination of natural factors and human activities rather than just a single natural cause. Spatial factors have also heavily influenced the causes of draught. This study was conducted in the Lam Ta Kong watershed, Thailand. In this study, the Fuzzy Analytic Hierarchy Process (FAHP) method was applied to evaluate the risk of agricultural drought and the GIS technique was employed to give full consideration to the ambiguity and uncertainty of the agricultural drought risk. There are five risk factors to consider in the agricultural drought risk assessment and they are divided in a total of fifteen criteria: physical factors (slope gradient and elevation), climatic (rainfall and aridity index), soil (texture, drainage, fertility, erosion, and soil salinity), land utilization (land use and land cover) and water resources (precipitation days, stream density, distance from an irrigation canal, and groundwater volume). These criteria determine the weight and score used to evaluate their parental risk factors. The Analytic Hierarchy Process (AHP) was applied together with the triangular fuzzy numbers (TFNs) method to assess the data obtained from the criteria to achieve the drought risk assessment. The results indicated that the overall risk of the Lam Ta Kong area was at a moderate risk of agricultural drought (50.45%), of which 15.63% of the total area was at a high risk of agricultural drought. Moreover, 0.40% of the total area located at the central part of the watershed was at a very high risk which was due to its saline soil with > 50% dense salt crust. This research indicated that the major factors causing droughts in the watershed were related to the soil factors, especially soil texture, soil fertility and soil salinity. These soil factors were considered as the driving factors of drought. The results of this study can be used for land use planning and water resource management in order to prepare for droughts in the watershed.
39
Moreno, J. L., M. Aboal, M. R. Vidal-Abarca, and M. L. Suárez. "Macroalgae and submerged macrophytes from fresh and saline waterbodies of ephemeral streams ('ramblas') in semiarid south-eastern Spain." Marine and Freshwater Research 52, no. 6 (2001): 891. http://dx.doi.org/10.1071/mf00008.
Full textAbstract:
Semiarid saline streams are uncommon and hence are seldom studied. Moreover, most studies on filamentous algae have been carried out in permanent freshwaters. Seventeen waterbodies from ephemeral streams of semiarid south-eastern Spain (‘ramblas’) were surveyed from a botanical, phycological and ecological point of view over a four-year period. Gradients of environmental conditions ranged from fresh to saline water (0.27 to 47 mS cm–1), from ephemeral to permanent and from pools to streams. Most of the sites were springs or streams that appeared in certain reaches as a result of the upwelling of groundwater. In total, 47 species of submerged macrophytes and macroalgae were recorded, with 1–18 species per site. The most diverse orders were Zygnematales, Oedogoniales and Charales, although the importance and diversification of Vaucheriales in some places was also of note. Multivariate analysis identified salinity as the main factor explaining species distribution. Conductivity ranges for species were compared with other saline habitats such as saline lakes, saltmarshes or coastal lagoons. Finally, this study broadens the ecological range of some taxa and highlights the ecological importance of these kinds of systems for the preservation of biodiversity in arid lands.
40
Borisik, A. L., V. E. Demidov, K. V. Romashova, and A. L. Novikov. "Internal drainage network and characteristics of the Aldegondabreen runoff (West Spitsbergen)." Arctic and Antarctic Research 67, no. 1 (March 23, 2021): 67–88. http://dx.doi.org/10.30758/0555-2648-2021-67-1-67-88.
Full textAbstract:
The polythermal Aldegondabreen is one of the most widely studied glaciers of the Nordenskjöld Land (Svalbard). However, the structure of its internal drainage network remains poorly understood. In order to determine the position and hydro-chemical characteristics of the surface and internal drainage channels of the glacier complex studies were carried out including ground penetrating radar (GPR) measurements and hydrological surveys. The GPR profiling performed in 2018–2020 identified four channels of internal drainage network, two of which are found along the northern side of the glacier in the area of cold ice and are subglacial. The other two are located in the area of temperate ice along the southern side of the glacier and are englacial, stretching at the cold-temperate surface. At the outlet grotto, the subglacial waters have a bicarbonate-calcium composition and low salinity (electrical conductivity 30–40 μS/cm), inherited from the surface meltwater streams that enter the moulins in the upper part of the glacier. No noticeable increase in mineralization occurs during the movement of the flow along the glacier bed. The englacial channels’ waters at the outlet grotto have the same bicarbonate-calcium composition but a higher salinity (electrical conductivity 100 μS/cm), which we attribute to the filtration through the rocks of the riegel near the Aldegonda terminus, or, alternatively, to the influx of the groundwater at the same spot. Measuring the hydrochemistry of the Aldegonda river tributaries both on the glacier’s surface, at the grottos and on the moraine in the valley made it possible to identify the zone of enrichment of the main volume of the low-mineralization glacial meltwater of bicarbonate-calcium composition by the high-mineralization (electrical conductivity up to 760 μS/cm) groundwater of sulphate-calcium composition coming from the springs on the riegel in front of the glacier’s terminus in the central part of the Aldegonda Valley. Presumably, the springs are fed by the deep filtration of melted glacial waters along the Aldegonda subglacial talik.
41
BEQAJ, Blerina. "ASSESSING THE ENVIRONMENTAL IMPACT OF ROADWAY’S CONSTRUCTION ON ADJACENT WATER RESOURCES: A CASE STUDY OF THE SOUTHERN PART OF ALBANIA." Scientific Journal of Silesian University of Technology. Series Transport 114 (January 1, 2022): 5–13. http://dx.doi.org/10.20858/sjsutst.2022.114.1.
Full textAbstract:
Water is one of nature’s resources. As urbanisation grows, new roadways and highways are constructed for the transport sector and development. Due to roadway infrastructure, the development of the quality of surface water bodies in close proximity to roads is deteriorating and has become a major environmental challenge. Considered as one of the major nonpoint pollution sources, the construction of new roadways can have short and long-term effects on water quality conditions. This study revealed that road construction activities may be responsible for introducing pollutants in nearby water sources, leading to the deterioration of water quality. The roadway expansion activities affect both the surface and groundwater quality. Furthermore, this study was conducted to assess the effects of a road construction project situated in the southern part of Albania, on physic-chemical parameters of surface water by collecting water samples from Skotini stream. The analysed parameters included pH, dissolved oxygen (DO), biological oxygen demand (BOD5), chemical oxygen demand (COD), electrical conductivity (ECw), total dissolved solids (TDS), salinity, nitrites (NO2-), ammonium (NH4+) and total phosphorus (Ptot). The results revealed that all physic-chemical parameters analysed in the laboratory are between the normal standards classifying these waters as very clean. Further surveillance for quality assessment of water sources near roadway’s construction activities is needed. Various best management practices have been developed and implemented to prevent negative environmental impacts in the transport sector and roadway construction activities. Results of the water quality help strengthen the theory that roadway construction projects in the transport sector, using appropriate best management practices, could yield minimal impact on the overall water quality of surrounding water bodies.
42
Pandey, Gaurav. "Wetlands and their Role in Water Conservation: A Review." International Journal of Advance Research and Innovation 4, no. 1 (2016): 84–88. http://dx.doi.org/10.51976/ijari.411612.
Full textAbstract:
A wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water. Wetlands include swamps, marshes, and bogs. The water found in wetlands can be saltwater, freshwater, or brackish. The world's largest wetland is the Pantanal which straddles Brazil, Bolivia and Paraguayan South America. Wetlands are considered the most biologically diverse of all ecosystems. Plant life found in wetlands includes mangrove, water lilies, cattails, sedges, tamarack, black etc. A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. Saltwater is water from a sea or ocean. Fresh water is naturally occurring water on the Earth's surface in bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Brackish water is water that has more salinity than fresh water, but not as much as seawater spruce, cypress, gum tree, and many others. Animal life includes many different amphibians, reptiles, birds, insects, and mammals. In many locations, such as the United Kingdom, Iraq, South Africa and the United States, wetlands are the subject of conservation efforts and biodiversity Action Plans.
43
Forester, Richard M. "OSTRACODE ASSEMBLAGES FROM SPRINGS IN THE WESTERN UNITED STATES: IMPLICATIONS FOR PALEOHYDROLOGY." Memoirs of the Entomological Society of Canada 123, S155 (1991): 181–201. http://dx.doi.org/10.4039/entm123155181-1.
Full textAbstract:
AbstractOstracodes are a diverse group of marine and continental crustaceans that have radiated into virtually all oxygenated aquatic environments that persist for more than about a month. Continental ostracodes live in both surface water and groundwater.Ostracodes living in springs and seeps have typically been the subject of systematic rather than ecologic studies. These taxa may or may not occur in other surface-water bodies. Similarly, lacustrine taxa may or may not be found in springs. Spring taxa occurring in other surface waters are often found in ponds, marshes, streams, or on the edges of lakes where groundwater discharge is important. Groundwater discharge, unlike lake water, shows limited and predictable variability in chemistry and temperature during the year. That level of variability relative to lake water may define particular ostracode environmental gradients. The gradients would range from stable, high-volume discharge springs occupied principally by spring species to high variability lakes occupied largely by lacustrine species.Ostracode occurrences may also be described by parameters such as temperature, solute (dissolved ion) composition, solute concentration (salinity, conductivity, ionic strength), and calcite saturation indices. A plot of these parameters associated with the presence of a taxon illustrates its physiologic response to the environment, a field. Three general fields bounded by chemical parameters are delineated by existing data. Those fields are as follows: (1) a restricted range and (2) a full range of fresh water, and (3) both fresh and saline water. Fields bounded by temperature and chemistry are also recognized. The fields also offer a way of describing ostracode occurrences in terms of hydrogeology and climate.If ostracode occurrences are limited by major chemical and physical properties of the aquatic environment, then their habitat may be defined by certain physical–chemical principles. The same physical–chemical principles must apply to the past. The ecology of extinct taxa may, therefore, be defined in the same environmental terms as those for extant taxa.
44
S. A., Ngah, and Ekpebegh U.N. "Status of Water Supply in Parts of Umuahia South Local Government Area, Abia State, Nigeria: A Look at Alternatives." Journal of Advance Research in Applied Science (ISSN: 2208-2352) 3, no. 4 (April 30, 2016): 40–56. http://dx.doi.org/10.53555/nnas.v3i4.650.
Full textAbstract:
The study investigated the water supply sources in Old Umuahia semi-urban district in Abia State, Nigeria. Emphasis was on the quality and quantity of available water sources. Some socio-economic considerations such as family sizes, proximity of source, quality and quantity of water actually used per day as compared with quantity required per day were all evaluated. Water supply shortfall was hence evaluated and quantified. Different sources of water in use were evaluated. They include motorized boreholes, Springs, Streams, commercial water vendors and harvested rainwater. The study showed that the majority of residents had bread winners who were civil servants (48%) with an average family size of 5-8 people. Most people practice conjunctive water use of water combining more than one source with comparative advantages. 89% of the people depend on water boreholes for their drinking water supplies. Available hydrogeological data from the area were reviewed. The area was found to be underlain by a prolific aquifer capable of sustainably supplying the area. Water samples were collected from the different water sources and analysed for concentration of key physico-chemical parameters such as pH, Dissolve d Oxygen, conductivity, turbidity, totaldissolved solids, total hardness, chloride, salinity, total alkalinity, copper, iron, manganese, sulphate, chromium, colour and zinc. The results were compared with World Health Organisation (WHO) standards for domestic water supply. From the results, water in the area was found to be acidic with pH values ranging from 4.9 to 5.15 (mean value, 5.02). All the other physico-chemical parameters showed values that plot within the limit of acceptability of WHO standards except for two boreholes sources, two streams sources and samples from the commercial water vendors whose water samples indicated serious bacteriological contamination. Supplies from groundwater sources is of highest quality. Since the area is underlain by aquifers with excellent water yielding properties, the studyrecommended the development of water supply in the area mainly from groundwater sources. This will require additional hydrogeological studies to determine the number, location and depths of new boreholes to serve the domestic water demands of the inhabitants of the area. Existing four boreholes are grossly inadequate to meet and sustain the domestic water needs of about 8000 people who presently inhabit the area. Similarly, people should be discouraged from using the water from commercial water vendors for domestic purposes. This will drastically reducethe incidence of water-borne diseases in the area
45
Finsterle, Stefan, Richard A. Muller, John Grimsich, Ethan A. Bates, and John Midgley. "Post-Closure Safety Analysis of Nuclear Waste Disposal in Deep Vertical Boreholes." Energies 14, no. 19 (October 5, 2021): 6356. http://dx.doi.org/10.3390/en14196356.
Full textAbstract:
Isolation of spent nuclear fuel assemblies in deep vertical boreholes is analyzed. The main safety features of the borehole concept are related to the repository’s great depth, implying (a) long migration distances and correspondingly long travel times, allowing radionuclides to decay, (b) separation of the repository from the dynamic hydrological cycle near the land surface, (c) stable geological and hydrogeological conditions, and (d) a geochemically reducing environment. An integrated simulation model of the engineered and natural barrier systems has been developed to examine multiple scenarios of the release of radionuclides from the waste canisters, the transport through a fractured porous host rock, and the extraction of potentially contaminated drinking water from an aquifer. These generic simulations include thermal effects from both the natural geothermal gradient and the heat-generating waste, the influence of topography on regional groundwater flow, moderated by salinity stratification at depth, and the role of borehole sealing. The impact of these processes on the transport of select radionuclides is studied, which include long-lived, soluble, sorbing or highly mobile isotopes along with a decay chain of safety-relevant actinide metals. The generic analyses suggest that a deep vertical borehole repository has the potential to be a safe option for the disposal of certain waste streams, with the depth itself and the stable hydrogeological environment encountered in the emplacement zone providing inherent long-term isolation, which allows for reduced reliance on a complex engineered barrier system.
46
Krishan, Gopal. "Groundwater Salinity." Current World Environment 14, no. 2 (June 8, 2019): 186–88. http://dx.doi.org/10.12944/cwe.14.2.02.
Full text
47
Lovatt, Carol J. "Properly Timing Foliar-applied Fertilizers Increases Efficacy: A Review and Update on Timing Foliar Nutrient Applications to Citrus and Avocado." HortTechnology 23, no. 5 (October 2013): 536–41. http://dx.doi.org/10.21273/horttech.23.5.536.
Full textAbstract:
Foliar fertilization efficiently meets the nutrient demand of tree fruit crops during periods when soil conditions (low or high temperatures, low or excess soil moisture, pH, salinity) render soil-applied fertilizers ineffective, when nutrients (e.g., phosphate, potassium, and trace elements) become fixed in the soil, and when tree nutrient demand is high. Applying nutrients directly to leaves ensures that the metabolic machinery of the tree is not compromised by low availability of an essential nutrient. It should be noted that phloem mobile nutrients applied to the foliage are translocated to all tree parts, even feeder roots. Because foliar application of fertilizers can reduce nutrient accumulation in soil, runoff water, surface water (streams, lakes, ocean), and groundwater (drinking water supply), where they contribute to salinity, eutrophication, or nitrate contamination, with negative consequences to the environment and humans, it is highly desirable to replace soil-applied fertilizers at least in part with foliar-applied fertilizers. However, not all nutrients are taken up through leaves and, even if taken up, some nutrients are not phloem mobile. In addition, although foliar fertilizer rates are typically lower than soil fertilizer rates, application can be more costly. The goal has been to time the application of foliar fertilizers to key stages of citrus (Citrus sp.) and avocado (Persea americana) tree phenology when demand for the nutrient is likely to be high and especially when soil conditions are likely to compromise nutrient uptake by roots. This approach has proven successful for increasing yield, fruit size, and grower income even when the tree is not nutrient deficient by standard leaf analysis. Winter prebloom foliar-applied low-biuret urea was previously documented to increase total yield of both navel and ‘Valencia’ oranges (Citrus sinensis). Adaptation of this treatment to ‘Nules’ Clementine mandarin (Citrus reticulata) increased the yield of commercially valuable size fruit in two experiments. Foliar application of boron or low-biuret urea to ‘Hass’ avocado trees at the “cauliflower” stage of inflorescence development increased total yield; potassium phosphite applied at this stage of tree phenology increased the yield of commercially valuable size fruit.
48
Nour, Mohamed H., Ashraf Ghanem, Martin Buchholz, and Ahmed Nassar. "Greenhouse based desalination for brackish water management using bittern evaporative cooling technique." Water Supply 15, no. 4 (February 25, 2015): 709–17. http://dx.doi.org/10.2166/ws.2015.025.
Full textAbstract:
The Arab region is characterized by arid and semi-arid conditions with very limited renewable water resources. Most of the surface water comes from transboundary streams and most of the groundwater resources are fossil in nature. Water quality degradation and excessive use of pesticides and herbicides in agriculture pose severe environmental and health risks. The underlying research is a joint effort between Cairo University and the Technical University of Berlin to develop technologies and strategies for sustainable pesticide-free agriculture using saline or brackish water. This project builds on a previously implemented project in Spain by the German research partner that introduced the concept of Watergy, which presents an integrated desalination horticulture solar greenhouse. In this current research, the Watergy greenhouse is further developed to meet more arid climate requirements, reduce construction costs, and increase resource utilization efficiency. Several lab-scale experiments and a 100 m2 prototype were built in Egypt to optimize the process and answer research questions. Lessons learned from this project provided guidelines on the development of the most efficient approach of desalination and water management in the system, devised a cost-effective and efficient heat exchanger using low-cost local material, and established the feasibility of the system in the arid climate together with prospects for wider applications. The proposed greenhouse was estimated to be able to save in irrigation water 40% for cherry tomatoes and cucumbers, and 50% for bell peppers. Maximum crop yield can be achieved at extended upper salinity levels using the proposed greenhouse as follows: from 1,000 to 1,700 mg/L for cherry tomatoes; from 960 to 2,000 mg/L for bell peppers; and from 1,600 to 2,700 mg/L for cucumbers.
49
Soni, Prahlad, Yogita Dashora, Basant Maheshwari, Peter Dillon, Pradeep Singh, and Anupama Kumar. "Managed Aquifer Recharge at a Farm Level: Evaluating the Performance of Direct Well Recharge Structures." Water 12, no. 4 (April 9, 2020): 1069. http://dx.doi.org/10.3390/w12041069.
Full textAbstract:
A field study evaluated the performance of direct well recharge structures (DWRS) in order to harvest and filter farm runoff and its discharge into open dug wells to augment groundwater recharge. This was undertaken between 2016 and 2018 using a total of 11 wells in the Dharta watershed, situated in a semi-arid hardrock region of Udaipur district, Rajasthan, India. The depth to water level in each DWRS well was monitored weekly for 1 to 3 years before and after the DWRS was established, and water samples were taken for water quality analysis (pH, electrical conductivity (EC), total dissolved solids (TDS), turbidity, fluoride, and Escherichia coli) before and during the monsoon period. For each DWRS well, two control wells in close proximity were also monitored and sampled. Five of the DWRS established in 2018 also had flow meters installed in order to measure discharge from the filter to the well. The volume of water recharged through DWRS into individual wells during the 2018 monsoon ranged from 2 to 176 m3 per well. Although the mean rise in water levels over the monsoon was higher in DWRS wells than in nearby control wells, the difference was not significant. Values of pH, EC, TDS, and F decreased in DWRS and control wells as each monsoon progressed, whereas the turbidity of wells with DWRS increased slightly. There was no significant difference between DWRS and control wells for pH, EC/TDS, turbidity, or fluoride. The presence of E. coli in DWRS wells was higher than in control wells, however, E. coli exceeded drinking water guidelines in all sampled wells. On the basis of this study, it is recommended that rural runoff should not be admitted to wells that are used for, or close to, wells used for drinking water supplies, even though salinity and fluoride concentrations may be reduced. For this study, none of the 11 DWRS wells produced sufficient additional recharge to potentially increase dry season irrigation supplies to justify expenditure on DWRS. This even applies to the DWRS well adjacent to a small ephemeral stream that had a significantly larger catchment area than those drawing on farmers’ fields alone. An important and unexpected finding of this study was that no sampled open dug well met drinking water standards. This has led to a shift in local priorities to implement well-head water quality protection measures for wells used for drinking water supplies. It is recommended that parapet walls be built around the perimeter of such dug wells, as well as having covers be installed.
50
Yan, Shao-feng, Shuang-en Yu, Yu-bai Wu, De-feng Pan, Dong-li She, and Jianzhong Ji. "Seasonal Variations in Groundwater Level and Salinity in Coastal Plain of Eastern China Influenced by Climate." Journal of Chemistry 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/905190.
Full textAbstract:
The coastline of China is approximately 18,000 km long. In most coastal cities, seawater intrusion is a serious threat to groundwater resources. Nine shallow monitoring wells were constructed to study the dynamics of shallow groundwater level and salinity in the coastal plain region of Jiangsu province, China. Results showed that precipitation, evaporation, and river stage affected the groundwater level in our study area. Positive correlations were observed among the groundwater level, precipitation, and river stage; then negative correlation existed between the groundwater level and evaporation. The influencing factors on the groundwater level were in the order precipitation > river stage > evaporation. Sufficient precipitation during the wet season diluted the groundwater salinity. After the dilution, between two continuous precipitation events, the groundwater salinity increased as the groundwater level decreased. During the dry season, the groundwater salinity rapidly increased and reached its peak in December. The groundwater salinity in December was 23 times higher than that in July. The groundwater level and salinity in this study were generally associated with the season. Climate factors led to fluctuation of groundwater levels and salinity during the wet season, and seawater intrusion increased the groundwater salinity during the dry season.