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Nada, I. Made, I. Wayan Redana, I. G. B. Sila Dharma und A. A. Gde Agung Yana. „Model Penataan Lahan Penanggulangan Erosi Berbasis Masyarakat Di Kawasan Danau Batur“. Bumi Lestari Journal of Environment 18, Nr. 1 (01.02.2018): 1. http://dx.doi.org/10.24843/blje.2018.v18.i01.p01.
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Erosion control in the community-based Lake Batur area is directed to maintain the balance of Lake Batur. Erosion triggered by the pattern of management of agricultural lands less attention to aspects of soil and water conservation. The purpose of this research is; (1) to obtain a community-based erosion control model, (2) Land management Mapping on the edge of the lake, (3) erosion control strategy at the edge of the lake. This research field experiment and surpei, sampling is done by purposive sampling with amount of 64 sample. The socio-economic support data of the community was determined by 180 respondents in cluster sampling. Interviews and questionnaires are closed questions on a conventional scale. The characteristics of the lake were analyzed descriptive statistics using the SPSS tool. Land mapping is done by GPS method with GIS device. Predict erosion using the Universal Soil Loss Equation (USLE) Model, for sedimentation using the Stanford Sediment model. The analysis of the rate due to erosion, done by non linear regression analysis. The analysis shows that the settlement has an average of 115,85%, plantation 245,50% and sedimentation level 1,017,93 m3 / year. Sedimentation was tested on both sides with a 95% confidence level on the modeled sediment data. Conclusions to tackle erosion using a community-based Terracing Mekar land arrangement model that collaborates with elephant grass and vetiveria.
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Nada, I. Made, I. Wayan Redana, I. G. B. Sila Dharma und A. A. Gde Agung Yana. „Terasering Mekar Erosion Control Model in Batur Lake Zone“. International Journal of Contemporary Research and Review 10, Nr. 01 (16.01.2019): 20254–59. http://dx.doi.org/10.15520/ijcrr.v10i01.642.
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Erosion control in Lake Batur area is community-based directed to maintain lake balance. The aims of this research is; (1) to obtain a community-based erosion control model, (2) to analyze the role of communities in the application of land management models. (3) Analyzing other plant species in collaboration with the arrangement model . (4) Analyzing the impact of terraces blooming against sedimentation. This research is field experiments and surveys, and the sampling was conducted by purposive sampling with 64 samples. The socio-economic support data of the community was determined by 180 respondents by cluster sampling. Interviews and questionnaires were conducted through closed questions on a conventional scale. The characteristics of the lake were analyzed statistically and descriptively by using the SPSS tool. Land mapping was conducted by GPS method with GIS device. Prediction of erosion was by using USLE Model, while sedimentation was measured by the Stanford Sediment model. The analysis shows that the increase of settlement is averagely of 115,85%, plantation is 245,50% and the sedimentation level is 1,017,93 m3 / year. Conclusions and outcomes were in the form of community-based terracing model that collaborate with elephant grass and vetiveria plants.
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Nada, I. Made, I. Wayan Redana, IG B. Sila Dharma und A. A. Gde Agung Yana. „Community-based erosion control model in Batur Lake zone“. MATEC Web of Conferences 276 (2019): 04008. http://dx.doi.org/10.1051/matecconf/201927604008.
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Erosion control in Lake Batur area is community-based directed to maintain lake balance. The aims of this research is: 1) to obtain a community-based erosion control model, 2) to analyze the role of communities in the application of land management models, 3) to analyze other plant species in collaboration with the arrangement model, and 4) to analyze the impact of terraces blooming against sedimentation. This research is field experiments and surveys, and the sampling was conducted by purposive sampling with 64 samples. The socio-economic support data of the community was determined by 180 respondents by cluster sampling. Interviews and questionnaires were conducted through closed questions on a conventional scale. The characteristics of the lake were analyzed statistically and descriptively by using the SPSS tool. Land mapping was conducted by GPS method with GIS device. Prediction of erosion was by using USLE Model, while sedimentation was measured by the Stanford Sediment model. The analysis shows that the increase of settlement is averagely of 115.85%, plantation is 245.50% and the sedimentation level is 1,017,93 m3/year. Conclusions and outcomes were in the form of community-based terracing model that collaborate with elephant grass and vetiveria plants.
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Nada, I. Made, Ida Bagus Suryatmaja und I. Gusti Ngurah Alit Wiswasta. „MODEL PENANGGULANGAN SEDIMENTASI DANAU BERBASIS MASYARAKAT DI PULAU BALI“. Bumi Lestari Journal of Environment 17, Nr. 2 (01.08.2017): 100. http://dx.doi.org/10.24843/blje.2017.v17.i02.p02.
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Countermeasures of community-based lake sediments are directed at maintaining the dynamic balance of Lake Batur, Beratan Lake, Lake Buyan and Lake Tamblingan. Sedimentation process of this lake is triggered by the pattern of management of agricultural land on the edge of the lake is less attention to aspects of soil and water conservation. The purpose of this research is; (1) to obtain a community-based sedimentation prevention model, (2) Mapping Land management on the edge of the lake, (3) erosion control strategy at the edge of the lake. This research is field experiment and surpei research, sampling is done by purposive sampling at Batur Lake 20 samples, Beratan Lake 16 samples, Lake Buyan 16 samples and Danau Tamblingan 12 Sampel. The socio-economic support data of the community was determined by 180 respondents in cluster sampling. Interviews and questionnaires are closed questions on a conventional scale. Characteristics of the lake were analyzed descriptive statistics using SPSS analysis tool. Land mapping is done by GPS method with GIS device. Predict erosion using the Universal Soil Loss Equation (USLE) Model while for sedimentation using the Stanford Sediment model. Data analysis to find out the model of development of sedimentation rate in lake due to erosion that happened, done by non linear regreresi analysis. The results of the analysis are tested on both sides with 95% confidence level on sediment data that is modeled whether or not significant effect
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Torrecillas, Cristina, Carmen Zarzuelo, Jorge de la Fuente, Bismarck Jigena-Antelo und Gonçalo Prates. „Evaluation and Modelling of the Coastal Geomorphological Changes of Deception Island since the 1970 Eruption and Its Involvement in Research Activity“. Remote Sensing 16, Nr. 3 (29.01.2024): 512. http://dx.doi.org/10.3390/rs16030512.
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Deception Island is an active volcano with a submerged caldera open to the sea called Port Foster. Several post-caldera-collapsed volcanic events, as well as hydrodynamics, have changed its inner coastline, shaping new volcanic deposits. A hydrodynamic model is presented to predict accretion and erosion trends in this bay, which could have an impact on the mobility of researchers and tourists. New historical orthophotos and spatio-temporal differences between digital elevation and bathymetric models were used for validation purposes. The model reveals that the south-facing coast is more susceptible to erosion, while the east- or west-facing coast experiences sedimentation. A visual study for the periods 1970–2003 and 2003–2020 in Port Foster obtained similar annual erosion/accretion lineal rates (0.3–2 m/year) in the areas not affected by the last eruptive period, as well as increases of 0.023 km2/year and 0.028 km2/year of the inner bay and coastal sedimentation rates of 0.007 km2/year and 0.002 km2/year, respectively. Only part of the significant total volume loss is received within the bay, including its own erosion, and accumulates on the bay bottom. This is largely because the volume input is composed of snow, and it is also due to the transfer of material outside to balance the figures.
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Foerst, M., und N. Rüther. „Measuring bank retreat in fluvial environments with Terrestrial Laser Scanning (TLS)“. Earth Surface Dynamics Discussions 1, Nr. 1 (19.11.2013): 951–72. http://dx.doi.org/10.5194/esurfd-1-951-2013.
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Abstract. In the last years methods for measuring bank erosion and sedimentation have been used to understand the process of river migration to get a better understanding of river migration. For this purpose a river bank in a medium low land river has been chosen. The river bank has been measured with a terrestrial laser scanner with a high resolution over the last three years. The yielded point clouds have been filtered and digital elevation models (DEM) have been created. These DEMs have been used to compare the mass balance and slope gradient changes between the scans. To achieve this goal, the slope gradient has been averaged horizontally and vertically. In addition, statistical analyses have been used to verify the significance of changes between the scans. The results show that erosion and sedimentation processes occur simultaneous. Further is the slope gradient a valuable tool to investigate different sections within a point cloud from terrestrial laser scanner.
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Li, Yongshan, Xiaopeng Jia, Haibing Wang, Jian Wang und Qimin Ma. „Shrinking Desert Channel Response to Increasing Human Interferences and Changing Natural Factors in the Upper Yellow River“. Water 15, Nr. 24 (08.12.2023): 4226. http://dx.doi.org/10.3390/w15244226.
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Many rivers are tightly coupled and intersected with aeolian sand dunes, whose geomorphological evolution involves not only fluvial processes but also aeolian processes that pose a new challenge to fluvial geomorphological studies. However, due to few field studies, our overall understanding of the desert channel geomorphic process is limited. In this paper, we present an outstanding example of desert river channel evolution regulated by aeolian–fluvial interactions in the Ulan Buh Desert of the Yellow River, based on a long time series data set (1966–2019) of channel cross-sections. The results indicate that the lateral addition of aeolian sand, the water–sediment relationship and human interference have a significant role at different periods of channel evolution. Before 1986, higher discharge, lower sediment content and greater intensity of aeolian activity caused aeolian–fluvial interactions and a relative scouring and silting balance in the channel, with little human activity. From 1986 to 2000, an increase in large reservoir operation, vegetation coverage and floodplain farming, coupled with water–sediment relationship variation, caused rapid deposition and shrinkage of the river channel. From 2000 to 2014, the channel kept a slight scouring state. With Haibowan reservoir operation beginning in 2014, the talweg experienced rapid scouring and undercut rebound. However, an expanding and stable floodplain accelerated sedimentation on the floodplain and weakened river lateral erosion, indicating that the channel has shown a shrinkage trend. Meanwhile, wavelet analysis results indicate that human interferences and aeolian activities have no significant role in the periodical characteristics of the channel’s longitudinal erosion and deposition. Therefore, on the whole, increasing human interferences and decreasing wind dynamics have driven this desert wandering channel to be stable, and to gradually form a new balance between erosion and sedimentation.
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Outridge, P. M., R. W. Macdonald, F. Wang, G. A. Stern und A. P. Dastoor. „A mass balance inventory of mercury in the Arctic Ocean“. Environmental Chemistry 5, Nr. 2 (2008): 89. http://dx.doi.org/10.1071/en08002.
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Environmental context. Mercury (Hg) occurs at high concentrations in Arctic marine wildlife, posing a possible health risk to northern peoples who use these animals for food. We find that although the dramatic Hg increases in Arctic Ocean animals since pre-industrial times can be explained by sustained small annual inputs, recent rapid increases probably cannot, because of the existing large oceanic Hg reservoir (the ‘flywheel’ effect). Climate change is a possible alternative force underpinning recent trends. Abstract. The present mercury (Hg) mass balance was developed to gain insights into the sources, sinks and processes regulating biological Hg trends in the Arctic Ocean. Annual total Hg inputs (mainly wet deposition, coastal erosion, seawater import, and ‘excess’ deposition due to atmospheric Hg depletion events) are nearly in balance with outputs (mainly shelf sedimentation and seawater export), with a net 0.3% year–1 increase in total mass. Marine biota represent a small fraction of the ocean’s existing total Hg and methyl-Hg (MeHg) inventories. The inertia associated with these large non-biological reservoirs means that ‘bottom-up’ processes (control of bioavailable Hg concentrations by mass inputs or Hg speciation) are probably incapable of explaining recent biotic Hg trends, contrary to prevailing opinion. Instead, varying rates of bioaccumulation and trophic transfer from the abiotic MeHg reservoir may be key, and are susceptible to ecological, climatic and biogeochemical influences. Deep and sustained cuts to global anthropogenic Hg emissions are required to return biotic Hg levels to their natural state. However, because of mass inertia and the less dominant role of atmospheric inputs, the decline of seawater and biotic Hg concentrations in the Arctic Ocean will be more gradual than the rate of emission reduction and slower than in other oceans and freshwaters. Climate warming has likely already influenced Arctic Hg dynamics, with shrinking sea-ice cover one of the defining variables. Future warming will probably force more Hg out of the ocean’s euphotic zone through greater evasion to air and faster Hg sedimentation driven by higher primary productivity; these losses will be countered by enhanced inputs from coastal erosion and rivers.
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Eric, DIANGONE, AKOBE Apie Colette, Amani Etché Mireille, MONDE Sylvain und COULIBALY Aoua. „MORPHOLOGICAL EVOLUTION OF THE BOTTOM OF THE POTOU LAGOON OVER THE LAST TEN YEARS (COASTAL ZONE OF COTE D'IVOIRE)“. International Journal of Research -GRANTHAALAYAH 8, Nr. 10 (23.10.2020): 37–46. http://dx.doi.org/10.29121/granthaalayah.v8.i10.2020.1588.
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This study with a morphology and hydrosedimentology character was done to carry out a with an understanding the evolution of the channels and sedimentation in Potou lagoon in Ivory Coast starting from the realization of the bathymetric map. The bathymetry of this lagoon avered that the depths are lower than 2.11 m out of 22 km2, and presente three types of channels. In fact the channels in "U" represent a balance between the agents of accumulation and erosion. Channels resulting from processes of erosion which are in "V" and channels intermediate indicating an evolution of the type "V" in "U". In particular during these fourteen last years the Potou lagoon has sudden great phenomenon of deposit is a volume of +66791000.18 m³of sediments deposed on a surface which is thus estimated at 65.2 % of chenal surface. These deposits are certainly causes of full high funds in this lagoon. The mean velocity of sedimentation on Potou lagoon is thus estimated at 26.5 cm/year. As for the erosion, it could be estimated at-8487601 m³ a volume of on a surface wich is thus estimated at 34 % of chenal surface. The sedimentary budget would be thus estimated at+58303398.68449 m³ on a surface of 12.45 m2. A surface which is thus estimated at 0.8 %hasn’t sudden phenomenon of deposit or erosion. The bathymetric chart and the sedimentary budget of Potou lagoon are tools necessary for use of the stretch of water by the users. Thus, the zones at the risks determined on the bathymetric chart, such as the high bottom and the points of swirl generated by the depressions, will be easily avoided.
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Pandey, Alok Kumar, Sharad Kumar Tripathi und Avijit Mahala. „An Appraisal of Soil Erosion in Dehradun Valley“. Journal of Scientific Research 66, Nr. 05 (2022): 09–11. http://dx.doi.org/10.37398/jsr.2022.660502.
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In the recent past, there has been a very rapid increase in the developmental activities in the Himalayas in general and Dehradun Valley in particular. These comprise large-scale construction, roads, mining activity, overgrazing, and deforestation etc. leading to the land degradation. A near exponential population growth has placed a further heavy demand on already limited natural resources. High rainfall coupled with fragile rocks and good relief provides a dense network of stream system. The debris from landslides and mine waste cause inequilibrium in flow regime causing meandering in both mountain and valley streams. These problems pose serious threat to environmental and ecological balance in an already fragile eco-system. Landslide, river sedimentation, disruption to communication lines and depletion of water sources are some of the direct consequences of mass erosion problem. The effect of majority of casualties and other natural hazards due to mass erosion often disrupts economic and social fabric over a much wider area than the hazard site and prompt action is required in order to minimize these losses. There are several mass erosion problems but landslides, mine spoil stabilization and stream bank erosion problems are dominant and therefore selected for the present study.
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Easton, Z. M., D. R. Fuka, E. D. White, A. S. Collick, B. Biruk Asharge, M. McCartney, S. B. Awulachew, A. A. Ahmed und T. S. Steenhuis. „A multi basin SWAT model analysis of runoff and sedimentation in the Blue Nile, Ethiopia“. Hydrology and Earth System Sciences Discussions 7, Nr. 3 (25.06.2010): 3837–78. http://dx.doi.org/10.5194/hessd-7-3837-2010.
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Abstract. A multi basin analysis of runoff and erosion in the Blue Nile Basin, Ethiopia was conducted to elucidate sources of runoff and sediment. Erosion is arguably the most critical problem in the Blue Nile Basin, as it limits agricultural productivity in Ethiopia, degrades benthos in the Nile, and results in sedimentation of dams in downstream countries. A modified version of the Soil and Water Assessment Tool (SWAT) model was developed to predict runoff and sediment losses from the Ethiopian Blue Nile Basin. The model simulates saturation excess runoff from the landscape using a simple daily water balance coupled to a wetness index in ways that are consistent with observed runoff processes in the basin. The spatial distribution of landscape erosion is thus simulated more correctly. The model was parameterized in a nested design for flow at eight and sediment at two subbasin locations in the basin. Subbasins ranged in size from 4.8 to 174 000 km2, and interestingly, the partitioning of runoff and infiltrating flow could be predicted by topographic information. Model predictions showed reasonable accuracy (Nash Sutcliffe Efficiencies ranged from 0.53–0.92) with measured data across all sites except Kessie, where the water budget could not be closed; however, the timing of flow was well captured. Runoff losses increased with rainfall during the monsoonal season and were greatest from shallow soils. Analysis of model results indicate that upland landscape erosion dominated sediment delivery to the main stem of the Blue Nile in the early part of the growing season before the soil was wetted up and plant cover was established. Once plant cover was established in mid August landscape erosion was negligible and sediment export was dominated by channel processes and re-suspension of landscape sediment deposited early in the growing season. These results imply that targeting small areas of the landscape where runoff is produced can be the most effective at controlling erosion and protecting water resources. However, it is not clear what can be done to manage channel erosion, particularly in first order streams in the basin.
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Utomo, Puji. „Mrica Reservoir Sedimentation: Current Situation and Future Necessary Management“. Journal of the Civil Engineering Forum 3, Nr. 2 (12.09.2017): 365. http://dx.doi.org/10.22146/jcef.26640.
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Mrica Reservoir is one of many reservoirs located in Central Java that experienced a considerably high sedimentation during the last ten years. This condition has caused a rapid decrease in reservoir capacity. Various countermeasures have been introduced to reduce the rate of the reservoir sedimentation through catchment management and reservoir operation by means of flushing and/or dredging. However, the sedimentation remains intensive so that the fulfillment of water demand for electrical power generation was seriously affected. This paper presents the results of evaluation on the dynamics of the purpose of this research is to evaluate the sediment balance of the Mrica Reservoir based on two different scenarios, i.e. the existing condition and another certain type of reservoir management. The study on sediment balance was carried out by estimating the sediment inflow applying sheet erosion method in combination with the analysis of sediment rating curve. The measurement of the deposited sediment rate in the reservoir was conducted through the periodic echo sounding, whereas identification of the number of sediment that has been released from the reservoir was carried out through the observation on both flushing and dredging activities. The results show that during the last decade, the rate of the sediment inflow was approximately 5.869 MCM/year, whereas the released sediment from the reservoir was 4.097 MCM/year. In order to maintain the reservoir capacity, therefore, at least 1.772 MCM/year should be released from the reservoir by means of either flushing or dredging. Sedimentation management may prolong the reservoir’s service life to exceed the design life. Without sediment management, the lifetime of the reservoir would have finished by 2016, whereas with the proper management the lifetime may be extended to 2025.
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Saikia, Lalit, und Chandan Mahanta. „A Mass Balance Approach in Sediment Budgeting of Large Alluvial Rivers with special emphasis on the Brahmaputra in Assam“. Journal of The Indian Association of Sedimentologists 38, Nr. 2 (31.12.2021): 15–24. http://dx.doi.org/10.51710/jias.v38i2.115.
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Morphology of an alluvial river channel is the consequence of erosion, sediment transport and sedimentation in a river. Sediment budget accounts for the sources, sinks and redistribution pathways of sediments, solutes and nutrients in a unit region over unit time. Human activities are the most important factors that affect the variation in the pattern of river sediment load. This paper discusses sediment budget of a few large rivers by review of literature and estimation of sediment budget of Brahmaputra River in Assam using mass balance approach. An attempt has also been made to discuss human and climatic impact on sediment load of major rivers of the world. Total sediment load in the Brahmaputra River at downstream location (India-Bangladesh border) was estimated to be 814×106 t/year. Considering 10% of sediment load of the Brahmaputra as bed load, suspended sediment load at downstream was estimated to be 733×106 t/year. Tributaries, bank erosion and scouring of river bed were found to contribute 52%, 27% and 21% respectively to sediment load of Brahmaputra at downstream locations. In spite of limitations of the dependable data, future complexity due to climate change impact and hydropower dam initiative in upstream of the River, the study is a simplified approach in sediment budgeting of the Brahmaputra.
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Easton, Z. M., D. R. Fuka, E. D. White, A. S. Collick, B. Biruk Ashagre, M. McCartney, S. B. Awulachew, A. A. Ahmed und T. S. Steenhuis. „A multi basin SWAT model analysis of runoff and sedimentation in the Blue Nile, Ethiopia“. Hydrology and Earth System Sciences 14, Nr. 10 (11.10.2010): 1827–41. http://dx.doi.org/10.5194/hess-14-1827-2010.
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Abstract. A multi basin analysis of runoff and erosion in the Blue Nile Basin, Ethiopia was conducted to elucidate sources of runoff and sediment. Erosion is arguably the most critical problem in the Blue Nile Basin, as it limits agricultural productivity in Ethiopia, degrades benthos in the Nile, and results in sedimentation of dams in downstream countries. A modified version of the Soil and Water Assessment Tool (SWAT) model was developed to predict runoff and sediment losses from the Ethiopian Blue Nile Basin. The model simulates saturation excess runoff from the landscape using a simple daily water balance coupled to a topographic wetness index in ways that are consistent with observed runoff processes in the basin. The spatial distribution of landscape erosion is thus simulated more correctly. The model was parameterized in a nested design for flow at eight and sediment at three locations in the basin. Subbasins ranged in size from 1.3 to 174 000 km2, and interestingly, the partitioning of runoff and infiltrating flow could be predicted by topographic information. Model predictions showed reasonable accuracy (Nash Sutcliffe Efficiencies ranged from 0.53–0.92) with measured data across all sites except Kessie, where the water budget could not be closed; however, the timing of flow was well captured. Runoff losses increased with rainfall during the monsoonal season and were greatest from areas with shallow soils and large contributing areas. Analysis of model results indicate that upland landscape erosion dominated sediment delivery to the main stem of the Blue Nile in the early part of the growing season when tillage occurs and before the soil was wetted up and plant cover was established. Once plant cover was established in mid August landscape erosion was negligible and sediment export was dominated by channel processes and re-suspension of landscape sediment deposited early in the growing season. These results imply that targeting small areas of the landscape where runoff is produced can be the most effective at controlling erosion and protecting water resources. However, it is not clear what can be done to manage channel erosion, particularly in first order streams in the basin.
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Azmeri, Azmeri, Alfiansyah Yulianur, Uli Zahrati und Imam Faudli. „Effects of irrigation performance on water balance: Krueng Baro Irrigation Scheme (Aceh-Indonesia) as a case study“. Journal of Water and Land Development 42, Nr. 1 (01.09.2019): 12–20. http://dx.doi.org/10.2478/jwld-2019-0040.
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Abstract Krueng Baro Irrigation is focused on increasing the productivity of food crops in Pidie District, Aceh Province, Indonesia. However, due to the age of the irrigation infrastructure (more than 30 years) and its large networks, it is necessary to investigate the actual water conveyance efficiency. This study aimed to evaluate the conveyance efficiency of primary and secondary channels of the irrigation system, as well as to create a water balance model based on the actual water conveyance efficiency. The model by using Excel Solver with its objective function is to maximize the area of the irrigated land. Based on the optimization model of the water balance, the design condition can irrigate an area of 9,496 ha (paddy-I), 4,818 ha (paddy-II), and 11,950 ha (onion). The measurement results reported that the actual efficiency of Baro Kanan and Baro Kiri was 56% and 48% smaller compared to the efficiency of the designs (65%). The water loss was due to the damage to the channel lining and channel erosion resulting in the high sedimentation, leakage, and illegal water tapping. These lead to a decrease in the area of the irrigated land. Based on the optimization model of the actual water balance, the irrigated land was reduced to 7,876 ha (paddy I) and 3,997 ha (paddy-II) while it remained the same for onion. Therefore, to increase the efficiency, the regular maintenance and operations are required by fixing the damaged irrigation structure and channels, the maintenance of sedimentation, and the strict regulation of illegal water tapping.
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Maisch, Max, Wilfried Haeberli, Martin Hoelzle und Jörg Wenzel. „Occurrence of rocky and sedimentary glacier beds in the Swiss Alps as estimated from glacier-inventory data“. Annals of Glaciology 28 (1999): 231–35. http://dx.doi.org/10.3189/172756499781821779.
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AbstractThe occurrence of rocky and sedimentary glacier beds in the Swiss Alps was investigated using two approaches: (1) a detailed and systematic classification of glacier forefields in the completely revised Swiss glacier inventory; and (2) the application of an algorithm for estimating bed characteristics from glacier-inventory data. The algorithm is based on the assumption that the sediment balance of a glacierized catchment, i.e. the ratio between debris input from the surrounding rock walls and debris evacuation by the meltwater stream, determines the occurrence of rocky, sedimentary or mixed beds. The processes which govern the sediment balance within a glacierized catchment cannot be easily observed or measured in the field. However, the main factors reflecting them can be organized in the form of an erosion—sedimentation index. This index discriminates between glaciers eroding into bedrock and those building up thick sediment beds and, thus, allows for rough assessments concerning bed characteristics. Sedimentary and mixed sedimentary—rocky glacier beds clearly predominate in the Swiss Alps, but more detailed spatial analysis is required for better predictions.
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Pirsouw, Martha Natalia, Joko Nugroho, Faizal Immaddudin Wira Rohmat, Nabila Siti Burnama, Arno Adi Kuntoro, Mohammad Farid und Hadi Kardhana. „Study of sediment transport distribution pattern after normalization in the Majalaya Area, Citarum River“. E3S Web of Conferences 467 (2023): 01028. http://dx.doi.org/10.1051/e3sconf/202346701028.
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Majalaya area in West Java, Indonesia, is prone to extreme rainfall events that cause flooding of the Citarum River. The river flows through the area, naturally containing sediments from erosion upstream that disturb the river balance. Some flat areas of the river retain sediments and cause excessive accumulation, resulting in changing the storage capacity of the river. The accumulation disrupts the flow of water and causes flooding in the area. To mitigate this problem, the River Basin Authority has implemented sediment dredging and river normalization with a total length of 5.4 km in 2020, successfully preventing flooding in the first year. However, subsequent floods that affected more than 7,000 people return to occur due to changes in land use, human activities, and unmanaged erosion upstream. This study examines the sediment accumulation pre-2020, immediately after the normalization efforts 2020, and the current sediment profile 2022. The result provides an overview of the river's morphology, sediment distribution patterns, and potential future profiles. The research results can be used to evaluate flood management risk in the area, including the compound flood risk caused by continuous sedimentation and climate change, e.g., heavier and longer rainfall.
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Svetlitchnyi, А. A., und A. V. Piatkova. „Spatially distributed GIS-realized mathematical model of rainstorm erosion losses of soil“. Journal of Geology, Geography and Geoecology 28, Nr. 3 (10.10.2019): 562–71. http://dx.doi.org/10.15421/111953.
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In connection with the wide and ever increasing spread of erosion degradation of agricultural lands in Ukraine, the task of developing mathematical models and methods for calculating water erosion of soils corresponding to the current level of erosion study and the demands of soil protection practices is becoming increasingly important. The article is devoted to the development of a spatially distributed GIS-implemented mathematical model of rainstorm soil erosion, which accounts for most of the annual soil losses (in the Steppe zone, for example, about 90 %). The development of the model is based on the most theoretically and informationally grounded model for the Steppe and Forest-Steppe of Ukraine , “the logical-mathematical model of rainstorm soil outwash” developed by H. I. Shvebs (1974, 1981), as well as the results of theoretical and field studies and mathematical modeling of the slope runoff and water erosion of soil, carried out at the Department of Physical Geography and Environmental Management of Odessa I. I. Mechnikov National University in the 1990s - 2010s, and also the possibilities of modern geoinformation technologies. For the spatial implementation of the model, a raster model of spatial data and operators of the PCRaster GIS-package (University of Utrecht, the Netherlands) were used, integrated with the Basic programming language into a single system that provides an implementation of the computational algorithm. The developed physical-statistical model of soil erosion-sedimentation takes into account the peculiarities of the formation of slope runoff and soil outwash in conditions of excessive nonstationarity of heavy rainfall, as well as spatial heterogeneity of all major natural and economic factors of water erosion on a slope, including slope steepness, exposure, longitudinal and transverse forms of slopes, soil erodibility, structure of sown areas and anti-erosion measures. Checking the adequacy of the mathematical model was performed using observational data of four experimental catchments ; two runoff plots of the Moldavan water-balance station with total area of 0.08 ha, the Ploska catchment with area of 8.5 ha (Boguslav field experimental base of Ukrainian Hydrometeorological Institute) and the Sukha catchment with area of 63 ha (Veliko-Anadol water-balance station) with observation periods of 17-31 years. Comparison of the calculated average over the catchment area of mean annual values of rainstorm soil losses, with the corresponding values obtained from measurements on these catchments, made on the basis of Nash-Sutcliff efficiency criterion (NS), allowed us to evaluate the quality of the model as good (NS = 0.72).
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Tarigan, Trika Agnestasia, Nirmawana Simarmata, Nanda Nurisman und Yudha Rahman. „Analisis sedimen dan pengaruhnya terhadap kondisi garis pantai di kawasan pantai timur Kabupaten Lampung Selatan“. Journal of Science and Applicative Technology 4, Nr. 1 (15.06.2020): 26. http://dx.doi.org/10.35472/jsat.v4i1.249.
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The erosion and sedimentation process that occurred in the east coast of South Lampung is a natural process affecting the balance of coastal sediment transport and resulting in the instability of coastal lines to the loss of the coastal communities along the coast, such as silting the river and can disturb the traffic of fishing boats. This is seen as a natural process influenced by the magnitude of wave energy coming, the type and size of sediment deposited, and coastal morphology. This research aims to analyze sediment and its effect on the changing coastline. The calculation approach with the empirical formula against coastal sediment data and wave data is used to predict the natural processes occurring along the coast. Analysis of SPOT 6/7 satellite imagery years 2008, 2013, 2016, and 2018 is the next step to estimate the similarity with empirical calculation results. The results showed that the East Coast had a characteristic mud sediment size ranging from 0.0258 – 0033 mm with the highest wave from the east with a wave height above 2.57 m and a period above 8,015 S. Research locations tend to undergo sedimentation processes that are influenced by waves, grain size, and there are rivers carrying sediments and deposits in the river estuary.
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Heritage, George, und Neil Entwistle. „Impacts of River Engineering on River Channel Behaviour: Implications for Managing Downstream Flood Risk“. Water 12, Nr. 5 (11.05.2020): 1355. http://dx.doi.org/10.3390/w12051355.
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Although knowledge of sediment transport has improved over the last 25 years, our understanding of bedload transfer and sediment delivery is still based on a limited set of observations or on models that make assumptions on hydraulic and sediment transport processes. This study utilises repeat lidar survey data of the River Caldew above the City of Carlisle in the UK to investigate the balance of erosion and deposition associated with channel switching from an engineered and managed single thread channel to a naturalising incipient wandering system. Over the 11-year survey period (four bankfull flood events) around 271,000 m3 of sediment were delivered to the river and floodplain and 197,000 m3 eroded suggesting that storage rates of around 7000 m3/annum occurred. The balance of erosion and deposition is influenced by channelisation with very restricted overbank sedimentation and only limited local and transient in-channel bar deposition along the engineered reach (8000 m3 eroded). This contrasts with the activity of the naturalising reach downstream where a developing wandering channel system is acting to store coarse sediment in-stream as large bar complexes and the associated upstream aggrading plane bed reaches and overbank as splay deposits (87,000 m3 stored). Such behavior suggests that naturalisation of channelised systems upstream of flood vulnerable urban areas can have a significant impact on sediment induced flooding downstream. This conclusion must, however, be moderated in the light of the relatively small volumes of material needed to instigate local aggradation in over-capacity urban channels.
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Pereira, F. F., C. R. Fragoso Jr., C. B. Uvo, W. Collischonn und D. M. L. Motta Marques. „Assessment of numerical schemes for solving the advection–diffusion equation on unstructured grids: case study of the Guaíba River, Brazil“. Nonlinear Processes in Geophysics 20, Nr. 6 (17.12.2013): 1113–25. http://dx.doi.org/10.5194/npg-20-1113-2013.
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Abstract. In this work, a first-order upwind and a high-order flux-limiter schemes for solving the advection–diffusion equation on unstructured grids were evaluated. The numerical schemes were implemented as a module of an unstructured two-dimensional depth-averaged circulation model for shallow lakes (IPH-UnTRIM2D), and they were applied to the Guaíba River in Brazil. Their performances were evaluated by comparing mass conservation balance errors for two scenarios of a passive tracer released into the Guaíba River. The circulation model showed good agreement with observed data collected at four water level stations along the Guaíba River, where correlation coefficients achieved values up to 0.93. In addition, volume conservation errors were lower than 1% of the total volume of the Guaíba River. For all scenarios, the higher order flux-limiter scheme has been shown to be less diffusive than a first-order upwind scheme. Accumulated conservation mass balance errors calculated for the flux limiter reached 8%, whereas for a first-order upwind scheme, they were close to 18% over a 15-day period. Although both schemes have presented mass conservation errors, these errors are assumed negligible compared with kinetic processes such as erosion, sedimentation or decay rates.
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Amos, Deborah, und Shatirah Akib. „A Review of Coastal Protection Using Artificial and Natural Countermeasures—Mangrove Vegetation and Polymers“. Eng 4, Nr. 1 (08.03.2023): 941–53. http://dx.doi.org/10.3390/eng4010055.
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Any stretch of coastline requires protection when the rate of erosion exceeds a certain threshold and seasonal coastal drift fluctuations fail to restore balance. Coast erosion can be caused by natural, synthetic, or a combination of the two. Severe storm occurrences, onshore interventions liable for sedimentation, wave action on the coastlines, and rising sea levels caused by climate change are instances of natural factors. The protective methods used to counteract or prevent coastal flooding are categorized as hard and soft engineering techniques. This review paper is based on extensive reviews and analyses of scientific publications. In order to establish a foundation for the selection of appropriate adaptation measures for coastal protection, this research compiles literature on a combination of both natural and artificial models using mangrove trees and polymer-based models’ configurations and their efficiency in coastal flooding. Mangrove roots occur naturally and cannot be manipulated unlike artificial model configuration which can be structurally configured with different hydrodynamic properties. Artificial models may lack the real structural features and hydrodynamic resistance of the mangrove root it depicts, and this can reduce its real-life application and accuracy. Further research is required on the integration of hybrid configuration to fully optimize the functionality of mangrove trees for coastal protection.
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Deroin, Jean-Paul. „Evaluating the Impact of Engineering Works in Megatidal Areas Using Satellite Images—Case of the Mont-Saint-Michel Bay, France“. GeoHazards 4, Nr. 4 (10.11.2023): 453–74. http://dx.doi.org/10.3390/geohazards4040026.
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The Mont-Saint-Michel is known worldwide for its unique combination of the natural site and the Medieval abbey at the top of the rocky islet. But the Mont is also located within an estuarine complex, which is considerably silting up. For two decades, large-scale works were planned to prevent the Mont from being surrounded by the expanding salt meadows. The construction of a new dam over the Couesnon River, the digging of two new channels, and the destruction of the causeway were the main operations carried out between 2007 and 2015. The remote sensing approach is fully suitable for evaluating the real impact of the engineering project, particularly the expected large-scale hydrosedimentary effects of reestablishing the maritime landscape around the Mont. The migration of the different channels and the erosion-progradation balance of the vegetation through space and time are the main features to study. Between 2007 and 2023, the erosion of the salt meadows was significant to the south-west of the Mont but more limited to the south-east. During the same period, the sedimentation considerably increased to the north-east of the Bay, which seems to be facing the same silting-up problem. At this stage, the remote-sensing survey indicates mixed results for the engineering project.
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Azmeri, Azmeri, Devi Sundary, Cut Mutiawati und Hafnidar A. Rani. „An update on reservoir operating rules following changes on the effective capacity due to land erosion“. E3S Web of Conferences 340 (2022): 01008. http://dx.doi.org/10.1051/e3sconf/202234001008.
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Reservoirs play a role in decreasing the temporal variability of river flow by regulating the reservoir water release for several downstream water needs. The Keuliling Reservoir was built to meet the needs of irrigation water. However, the dry season in Aceh Besar Regency significantly impacts irrigation areas because water from the Keuliling Reservoir cannot meet the demands. During the dry season, which is also the beginning of the second rice planting season (for gadu rice variety), the water source of the Keuliling Reservoir significantly decreases. The rate of land erosion leads to sedimentation, which may cause a reduction in the effective reservoir capacity. A decline in reservoir function due to sedimentation can affect the reservoir’s performance. The reservoir operating rules need to be adjusted due to a decline in capacity caused by sedimentation. This study aims to develop updated reservoir operating rules that can be used as an operational guideline for the Keuliling Reservoir. The study used a non-linear program to optimize the reservoir operation, which required objective functions and constraints. Optimization will result in reservoir operations that can supply water according to the target rice field area in normal and wet years. The irrigation area is 578 hectares for Group I (Keuliling Upstream Irrigation Area) and 1053 ha for Group I (Keuliling Downstream Irrigation Area). However, in the dry year of Group I (DI Keuliling Hulu), with an irrigation area of 578 hectares, the rice planting pattern (one rice planting season) begins with the planting season in October I. In addition, in Group II (DI Keuliling Hilir), with an irrigation area of 781 ha, the rice planting pattern (one rice planting season) starts the planting season in October II. The reduced inflows during dry years have decreased the target irrigation area by 113 ha. This Keuliling Reservoir operating manual can determine the reservoir water release to balance it with needs and storage targets.
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Aryani, Intan, Ichwana Ichwana und Devianti Devianti. „Perkiraan Erosi dan Sedimen Menggunakan Erosion Potential Method (EPM) Pada Sub DAS Krueng Jreu“. Jurnal Ilmiah Mahasiswa Pertanian 7, Nr. 4 (13.11.2022): 905–11. http://dx.doi.org/10.17969/jimfp.v7i4.21822.
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Abstrak. Daerah Aliran Sungai (DAS) merupakan kesatuan ekosistem yang saling berinteraksi antara makhluk hidup dan lingkungannya. Hal tersebut tidak terlepas dari keseragaman biofisik yang dimiliki. Karakteristik biofisik akan memberikan pengaruh terhadap respon curah hujan yang jatuh pada DAS, hal tersebut menjadi pertimbangan dalam melakukan perkiraan limpasan permukaan, erosi, dan laju sedimentasi, sehingga mampu memberikan keseimbangan pada sistem DAS. Penelitian ini bertujuan untuk memperkirakan erosi dan sedimen yang terjadi pada Sub DAS Krueng Jreu menggunakan metode perkiraan Erosion Potential Method (EPM). Dengan menganalisis data sekunder, seperti data iklim selama 10 tahun (2012-2021), dan data spasial terdiri dari peta administrasi Sub DAS Krueng Jreu, peta geologi, peta kemiringan lereng, peta penggunaan lahan, peta jaringan sungai, peta DEM SRTM wilayah Aceh. Data tersebut digunakan untuk menganalisis Koefisien Intensitas Erosi (Z), Koefisien Suhu (T), dan Koefisien Sedimentasi (RU). Selanjutnya dilakukan perhitungan Volume Erosi tahunan (WSP), Laju Sedimen Spasial (GSP), dan Laju Sedimen Total (GS) pada wilayah Sub DAS Krueng Jreu. Hasil perhitungan menunjukkan bahwa geologi dan penggunaan lahan memberikan tingkat sensitivitas yang tinggi terhadap hasil koefisien intensitas erosi (Z), tetapi kemiringan lereng yang berbeda tidak mempengaruhi. Besar atau kecilnya suhu dan curah hujan berbanding lurus terhadap volume erosi tahunan (WSP) dan laju sedimen spasial (GSP), namun tingkat sensitivitas yang dimiliki curah hujan lebih besar daripada suhu. Volume erosi tahunan dan laju sedimen spasial terendah pada tahun 2019 sebesar 64.965,41 m3/km2/tahun dan 58.206,18 m3/km2/tahun. Sedangkan tertinggi terjadi pada tahun 2021 sebesar 101.500,71 m3/km2/tahun dan 90.940,21 m3/km2/tahun. Sehingga volume erosi dan laju sedimen pada Sub DAS Krueng Jreu memiliki hubungan yang sangat erat dengan curah hujan. Hal tersebut ditunjukkan dari hasil nilai koefisien determinasinya (R2) yaitu sebesar 0,9996 atau 99,96 %. Estimation of Erosion and Sediment Using the Erosion Potential Method (EPM) in Krueng Jreu WatershedAbstract. Watershed is an ecosystem unit that interacts with living things and their environment. This is inseparable from the biophysical uniformity it has. Biophysical characteristics will have an influence on the response of rainfall that falls on the watershed, this is a consideration in making estimates of surface runoff, erosion, and sedimentation rates, so as to provide a balance to the watershed system. This study aims to estimate the erosion and sediment that occurred in the Krueng Jreu sub-watershed using the Erosion Potential Method (EPM) estimation method. By analyzing secondary data, such as climate data for 10 years (2012-2021), and spatial data consisting of administrative maps of the Krueng Jreu watershed, geological maps, slope maps, land use maps, river network maps, DEM SRTM maps for the Aceh region. The data is used to analyze the Erosion Intensity Coefficient (Z), Temperature Coefficient (T), and Sedimentation Coefficient (RU). Subsequently, the annual Erosion Volume (WSP), Spatial Sediment Rate (GSP) and Total Sediment Rate (GS) were calculated in the Krueng Jreu sub-watershed area. The calculation results show that geology and land use provide a high level of sensitivity to the results of the coefficient of erosion intensity (Z), but different slopes do not affect. The size of the temperature and rainfall is directly proportional to the annual erosion volume (WSP) and the spatial sediment rate (GSP), but the sensitivity level of rainfall is greater than temperature. The lowest annual erosion volume and spatial sediment rate in 2019 were 64,965.41 m3/km2/year and 58,206.18 m3/km2/year. While the highest will occur in 2021 at 101,500.71 m3/km2/year and 90,940,21 m3/km2/year. So, the erosion volume and sediment rate in the Krueng Jreu sub-watershed have a very close relationship with rainfall. This is shown from the results of the coefficient of determination (R2) which is equal to 0.9996 or 99.96%.
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Abdullah, Najihah Hakimah, Saerahany Legori Ibrahim, Nur Aqilah Mohd Rosli, Rabitah Handan und Zamri Mohd. „Estimating Sediment Yield at Sungai Pusu Watershed using Soil and Water Assessment Tool (SWAT) Model“. CONSTRUCTION 3, Nr. 2 (22.12.2023): 215–22. http://dx.doi.org/10.15282/construction.v3i2.9741.
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Sediment yield is the net result of soil erosion and sediment deposition processes. In the watershed, sediment yields are dominantly determined by stream flow, drainage area, and channel size. Land-use activity conducted by human is one of the major contributions to the sediment yield in the watershed. The study area covered in this study is the Sungai Pusu which flows through International Islamic University Malaysia (IIUM). Significant amount of sediments is deposited in Sungai Pusu due to the improper land clearing activities that are taking place along the river’s main tributaries. As a result, the water quality of Sungai Pusu is rapidly deteriorating. Sediment yield estimation is crucial in order to design suitable measure to rehabilitate the river. The aim of this study is to estimate sediment yield at Sungai Pusu watershed using SWAT model. Remote sensing and Geographic Information System (GIS) were used to evaluate sedimentation over time in the Sungai Pusu watershed. The SWAT model was performed to simulate water balance, stream flow, and sediment yield. The annual sediment yield obtained by the model is 427-ton ha-1 year-1.
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Marcus Ata, Frankie, Mohd Khairul Amri Kamarudin, Nadzifah Yaakub, Noorjima Abd. Wahab, Mohd Ekhwan Toriman, Hafizan Juahir, Muhammad Barzani Gasim et al. „Impact of Hydrological Study to Water Quality Status in Kuantan River, Pahang, Malaysia“. International Journal of Engineering & Technology 7, Nr. 3.14 (25.07.2018): 35. http://dx.doi.org/10.14419/ijet.v7i3.14.16859.
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Water is a vital for all aspects of human and ecosystem survival. The evaluations of water quality parameters and hydrological status are necessary to enhance the performance of an assessment operation and develop better water resources management and plan. There are three sampling stations were selected along the Kuantan River. Seven water quality parameters were measured and Malaysian Department of Environment Water Quality Index (DOE-WQI) was calculated and classified based on the National Water Quality Standard, Malaysia (INWQS). The water balance status applied to determine the stability of inflows and outflows into and from the basin. As a result, all water quality parameters (DO, COD, BOD, TSS, NH3-N and pH) which categorized under the ranged of class II until class IV respectively. Kuantan River located in Pahang state, Malaysia which is significantly degrading due to human activities as well as urbanization in and within the area. Overall, the result showed that the estimated average sediment that flows out of Kuantan Rivers is 108.88tonnes/day (24 February 2017) and 44.917 tonnes/day (30 April 2017). The contributors of sedimentation problems in Kuantan River are from unsustainable land use such as urbanization and industrialization which trapping the bed sediments and river band erosion.
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Zhang, Zhimin, Yuanyi Qiu, Hao Xiong und Rui Tang. „Resolved CFD-DEM Simulation of Free Settling of Polyhedral Particles with Various Orientations: Insights Provided by Oscillation Behavior in Quiescent Liquid“. Journal of Marine Science and Engineering 11, Nr. 9 (26.08.2023): 1685. http://dx.doi.org/10.3390/jmse11091685.
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Particle settling is the process by which particulates move toward the bottom of a liquid, which can affect the sediment transport and energy balance of marine systems. However, the deficiency in understanding the resolved fluid–particle interactions with complex boundaries in the settling process awaits resolution. This study employs a hybrid approach that combines computational fluid dynamics (CFD) with the discrete element method (DEM) to fully simulate the free-settling behavior of polyhedral particles in water. The accuracy of the method is verified by comparing numerical results with experimental data of ellipsoidal particle settling. Two series of tests with horizontal and vertical particle release directions are established to investigate the effects of particle shape features, such as the aspect ratio (AR) and corner (C), on the particles’ mechanical behavior and hydrodynamic characteristics. The results demonstrate that particle shape exerts a substantial influence on fluid resistance, rotational motion, and fluid disturbance throughout the settling process. The maximum velocities in vertically released cases are roughly 1.2–1.3 times greater than those in horizontally released cases. The study highlights the potency of the resolved CFD-DEM method as a robust technique for comprehending fluid–particle phenomena within the marine geotechnical engineering, including sedimentation and erosion of seabed sediments.
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Grauso, S., G. Fattoruso, C. Crocetti und A. Montanari. „A spatially distributed analysis of erosion susceptibility and sediment yield in a river basin by means of geomorphic parameters and regression relationships“. Hydrology and Earth System Sciences Discussions 4, Nr. 2 (23.03.2007): 627–54. http://dx.doi.org/10.5194/hessd-4-627-2007.
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Abstract. In the present work, an application of statistical regression relationships utilising geomorphic parameters is attempted in a spatially distributed mode, in order to predict the amount of river sediment supply at varying sections of the drainage network. Simple and multiple regression relationships utilising drainage density Dd and hierarchical anomaly index Δa as independent variables were applied to the Calvano watershed (Central Italy) at different degree of subdivision in tributary drainage basins, so as to assess their contribution to the whole watershed sediment yield balance. In the same way, the role of small hill-reservoirs as sediment-trap and that of areas affected by badlands and of tributary basins exposure were also investigated. Results were tested on the basis of sedimentation estimates from selected reservoirs. The relationships provided a yearly specific sediment yield (SSY) value for the Calvano stream which is according to the average observed SSY in river basins of central Italy flowing to the Adriatic Sea. The use of simple statistical relationships, such as those here adopted, can allow to recognise the sections along the main stream which are more critical in terms of sediment accumulation, which, on turn, can cause sudden water discharge increments and dangerous floods. This approach can provide a tool enabling to locate the hydraulic risk and to point out the areas where soil conservation practices or hydraulic works, such as periodic maintenance of riverbeds, are needed in order to reduce soil erosion and sediment accumulation.
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Malawani, Mukhamad Ngainul, Djati Mardiatno, Bachtiar Wahyu Mutaqin, Indranova Suhendro, Nicky Setiawan, Fajrun Wahidil Muharram und Iwan Rhosadi. „Dynamics of the aeolian landform at the coastal geosite of Parangtritis sand dune area, Yogyakarta“. Journal of Degraded and Mining Lands Management 11, Nr. 3 (01.04.2024): 5839–47. http://dx.doi.org/10.15243/jdmlm.2024.113.5839.
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In 2014, Kelud, an active volcano in East Java, ejected ashes (hereafter termed KA; Kelud ash) that reportedly reached as far as Central Java and the Special Region of Yogyakarta (DIY). The KA deposits are observable in, among others, the coastal sand dune area in Parangtritis. Due to the active aeolian process, the KA layers can be found at different depths five years after the eruption. Thus, the KA can be used as a marker of the post-2014 aeolian activities at the Parangtritis dune, which was once classified as a degraded land and later recognized as a coastal geosite, ultimately allowing us to calculate the volume and sand transport rate. The research surveys performed at 25 points discovered volcanic ash layers at 1 cm to 26 cm below the surface. At some observed points, the ash deposits were found on the surface and continuously transported. This research observed an area of 60,000 m2 with an average of 8.5 cm thick sand layers lying above the KA layer. Based on the calculation, the total volume of the transported sand at the Parangtritis sand dune from 2014 to 2019 was approximately 5,100 m3. This volume is considerably small owing to various obstacles in the transport zones. Based on the five-year dynamic of the sand dune, this study suggested that restoration needs to be conducted immediately particularly in eliminating vegetation barriers to maintain the sediment balance (erosion-transport-sedimentation) of the coastal sand dune area.
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McGill, Paula, Uisdean Nicholson, Dirk Frei und David Macdonald. „Defining Regional and Local Sediment Sources in the Ancestral Colorado River System: A Heavy Mineral Study of a Mixed Provenance Unit in the Fish Creek-Vallecito Basin, Southern California“. Geosciences 13, Nr. 2 (31.01.2023): 45. http://dx.doi.org/10.3390/geosciences13020045.
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The Colorado River has flowed across the dextral strike-slip plate boundary between the North American and Pacific plates since the latest Miocene or earliest Pliocene. The Fish Creek-Vallecito Basin (FCVB) lies on the Pacific Plate in southern California, dextrally offset from the point where the modern Colorado river enters the Salton Trough; it contains a record of ancestral Colorado River sedimentation from 5.3–2.5 Ma. The basin stratigraphy exhibits a changing balance between locally derived (L-Suite) and Colorado River (C-Suite) sediments. This paper focuses on the Palm Springs Group (PSG), a thick fluvial and alluvial sequence deposited on the upper delta plain (between 4.2–2.5 Ma) when the Colorado was active in the area, allowing the detailed examination of the processes of sediment mixing from two distinct provenance areas. The PSG consists of three coeval formations: 1) Canebrake Conglomerate, a basin margin that has coarse alluvial fan deposits derived from surrounding igneous basement; 2) Olla Formation, fan-fringe sandstones containing L-Suite, C-Suite, and mixed units; and 3) Arroyo Diablo Formation, mineralogically mature C-Suite sandstones. Stratigraphic analysis demonstrates that the river flowed through a landscape with relief up to 2000 m. Satellite mapping and detailed logging reveal a variable balance between the two suites in the Olla Formation with an apparent upward increase in L-Suite units before abrupt cessation of Colorado sedimentation in the basin. Stable heavy mineral indices differentiate L-Suite (high rutile:zircon index: RZi 40–95) from C-Suite (RZi: 0–20). Both suites have garnet:zircon index (GZi) and apatite:tourmaline index (ATi) mostly above 50, although many L-suite and mixed Olla samples have much lower ATi (20–50), suggesting that the distal floodplain was wet and the local sediment had a longer residence time there, or went through several cycles of erosion and redeposition. Heavy mineral analysis, garnet geochemical analysis, and detrital zircon U-Pb age spectra allow us to quantify the amount of mixing from different sediment sources. These data show that about 30% of the mixed units are derived from the Colorado River and that up to 20% of the L-Suite is also derived from the Colorado River, suggesting that there was mutual cannibalisation of older deposits by fluvial channels in a transitional area at the basin margin. Although this study is local in scope, it provides an insight into the extent and nature of sediment mixing in a two-source system. We conclude that most ‘mixing’ is actually interbedding from separate sources; true mixing is facilitated by low subsidence rates and the rapid migration of fluvial channels.
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Gómez-Delgado, F., O. Roupsard, R. Moussa, G. le Maire, S. Taugourdeau, J. M. Bonnefond, A. Pérez et al. „Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica“. Hydrology and Earth System Sciences Discussions 7, Nr. 3 (17.05.2010): 3015–71. http://dx.doi.org/10.5194/hessd-7-3015-2010.
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Abstract. The profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment of Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry micro-basin (1 km2, steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a NS coefficient equal to 0.80, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R2=0.79, energy balance closed independently), soil water content (R2=0.49) and water table level (R2=0.90). An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow, 25% as evapotranspiration and the remaining 11% was attributed to deep percolation. The model indicated an interception loss equal to 4% of R, a surface runoff of 5% and an infiltration component of 91%. The modelled streamflow was constituted by 63% of baseflow originating from the aquifer, 29% of subsurface non-saturated runoff and 8% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement-capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives.
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Semiletov, I. P., N. E. Shakhova, I. I. Pipko, S. P. Pugach, A. N. Charkin, O. V. Dudarev, D. A. Kosmach und S. Nishino. „Space–time dynamics of carbon and environmental parameters related to carbon dioxide emissions in the Buor-Khaya Bay and adjacent part of the Laptev Sea“. Biogeosciences 10, Nr. 9 (11.09.2013): 5977–96. http://dx.doi.org/10.5194/bg-10-5977-2013.
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Abstract. This study aims to improve understanding of carbon cycling in the Buor-Khaya Bay (BKB) and adjacent part of the Laptev Sea by studying the inter-annual, seasonal, and meso-scale variability of carbon and related hydrological and biogeochemical parameters in the water, as well as factors controlling carbon dioxide (CO2) emission. Here we present data sets obtained on summer cruises and winter expeditions during 12 yr of investigation. Based on data analysis, we suggest that in the heterotrophic BKB area, input of terrestrially borne organic carbon (OC) varies seasonally and inter-annually and is largely determined by rates of coastal erosion and river discharge. Two different BKB sedimentation regimes were revealed: Type 1 (erosion accumulation) and Type 2 (accumulation). A Type 1 sedimentation regime occurs more often and is believed to be the quantitatively most important mechanism for suspended particular matter (SPM) and particulate organic carbon (POC) delivery to the BKB. The mean SPM concentration observed in the BKB under a Type 1 regime was one order of magnitude greater than the mean concentration of SPM (~ 20 mg L−1) observed along the Lena River stream in summer 2003. Loadings of the BKB water column with particulate material vary by more than a factor of two between the two regimes. Higher partial pressure of CO2 (pCO2), higher concentrations of nutrients, and lower levels of oxygen saturation were observed in the bottom water near the eroded coasts, implying that coastal erosion and subsequent oxidation of eroded organic matter (OM) rather than the Lena River serves as the predominant source of nutrients to the BKB. Atmospheric CO2 fluxes from the sea surface in the BKB vary from 1 to 95 mmol m−2 day−1 and are determined by specific features of hydrology and wind conditions, which change spatially, seasonally, and inter-annually. Mean values of CO2 emission from the shallow Laptev Sea were similar in September 1999 and 2005 (7.2 and 7.8 mmol m−2 day−1, respectively), while the CO2 efflux can be one order lower after a strong storm such as in September 2011. Atmospheric CO2 emissions from a thawed coastal ice complex in the BKB area varied from 9 to 439 mmol m−2 day−1, with the mean value ranged from 75.7 to 101 mmol m−2 day−1 in two years (September 2006 and 2009), suggesting that at the time of observations the eroded coastal area served as a more significant source of CO2 to the atmosphere than the tundra (mean value: 22.7 mmol m−2 day−1) on the neighboring Primorsky coastal plain (September 2006). The observed increase in the Lena River discharge since the 1990s suggests that increased levels of "satellite-derived" annual primary production could be explained by an increasing load of humic acids delivered to shelf water; in this water the color resulting from the presence of CDOM (colored dissolved organic matter) mimics the color resulting from the presence of Chl a when seen from space. Because the BKB area can be employed as an integrator of ongoing changes in the surrounding environment, we suggest that under ongoing changes, more nutrients, products of eroded OC transformation and river transport, will be delivered to the Arctic Ocean with its shrinking ice cover, potentially increasing primary production outside of the shallow East Siberian Arctic Shelf (ESAS). At the same time, because the ESAS is characterized by very low transparency which limits euphotic layer thickness, excessive pCO2 will not be utilized by photosynthesis but will rather be emitted to the atmosphere at increasing rates, affecting regional CO2 balance.
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Gómez-Delgado, F., O. Roupsard, G. le Maire, S. Taugourdeau, A. Pérez, M. van Oijen, P. Vaast et al. „Modelling the hydrological behaviour of a coffee agroforestry basin in Costa Rica“. Hydrology and Earth System Sciences 15, Nr. 1 (28.01.2011): 369–92. http://dx.doi.org/10.5194/hess-15-369-2011.
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Abstract. The profitability of hydropower in Costa Rica is affected by soil erosion and sedimentation in dam reservoirs, which are in turn influenced by land use, infiltration and aquifer interactions with surface water. In order to foster the provision and payment for Hydrological Environmental Services (HES), a quantitative assessment of the impact of specific land uses on the functioning of drainage-basins is required. The present paper aims to study the water balance partitioning in a volcanic coffee agroforestry micro-basin (1 km2, steep slopes) in Costa Rica, as a first step towards evaluating sediment or contaminant loads. The main hydrological processes were monitored during one year, using flume, eddy-covariance flux tower, soil water profiles and piezometers. A new Hydro-SVAT lumped model is proposed, that balances SVAT (Soil Vegetation Atmosphere Transfer) and basin-reservoir routines. The purpose of such a coupling was to achieve a trade-off between the expected performance of ecophysiological and hydrological models, which are often employed separately and at different spatial scales, either the plot or the basin. The calibration of the model to perform streamflow yielded a Nash-Sutcliffe (NS) coefficient equal to 0.89 for the year 2009, while the validation of the water balance partitioning was consistent with the independent measurements of actual evapotranspiration (R2 = 0.79, energy balance closed independently), soil water content (R2 = 0.35) and water table level (R2 = 0.84). Eight months of data from 2010 were used to validate modelled streamflow, resulting in a NS = 0.75. An uncertainty analysis showed that the streamflow modelling was precise for nearly every time step, while a sensitivity analysis revealed which parameters mostly affected model precision, depending on the season. It was observed that 64% of the incident rainfall R flowed out of the basin as streamflow and 25% as evapotranspiration, while the remaining 11% is probably explained by deep percolation, measurement errors and/or inter-annual changes in soil and aquifer water stocks. The model indicated an interception loss equal to 4% of R, a surface runoff of 4% and an infiltration component of 92%. The modelled streamflow was constituted by 87% of baseflow originating from the aquifer, 7% of subsurface non-saturated runoff and 6% of surface runoff. Given the low surface runoff observed under the current physical conditions (andisol) and management practices (no tillage, planted trees, bare soil kept by weeding), this agroforestry system on a volcanic soil demonstrated potential to provide valuable HES, such as a reduced superficial displacement-capacity for fertilizers, pesticides and sediments, as well as a streamflow regulation function provided by the highly efficient mechanisms of aquifer recharge and discharge. The proposed combination of experimentation and modelling across ecophysiological and hydrological approaches proved to be useful to account for the behaviour of a given basin, so that it can be applied to compare HES provision for different regions or management alternatives.
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Sugandi, Dede. „Model of Conservation on Sagara Anakan Environment“. Forum Geografi 27, Nr. 2 (10.12.2013): 131. http://dx.doi.org/10.23917/forgeo.v27i2.2372.
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Widespread decline in agricultural land and the impact on production decline caused extensive forest activities to meet the needs of the population. Activities that cause less environmental quality offset environmental balance changes. These changes due to deforestation, erosion, degraded land and natural resource degradation are exploited so that the function of ecological, economic and social life. Damaged ecosystems resulting in erosion, landslides in the watershed affect the sedimentation in Sagara Anakan sea. Silting, resulting in narrowing of fishing activities, tourism, sports, and services decreased crossings. Because of the problem and the purpose of this study proposed and analyzed a few questions: 1) How does the socio-economic impact of farmers in conserving the environment of Sagara Anakan ?, 2) How do people form of conservation and coastal of Sagara Anakan ?, 3) How model of integrated conservation in the watershed and coastal of Sagara Anakan ? and 4) What role do the people in the watershed and coastal on Sagara Anakan conservation ?. Study site covers an area of flow and Ci Ci Tanduy Beureum and Sagara Tillers waters. Activities of the population in the process of land affected when in Sagara tillers. The method used was a survey with a sample divided by the watershed upstream, downstream and coastal tengahm. Using statistical analysis techniques and geography, so that part of the watershed characteristics can be imaged. Shallowing Sagara Anakan, physically was affected by the physical condition of the easily eroded and accelerated by human activities. The activities of farmer on the watershed have done conservation unless doing reforestation, whereas the farmer on the swamp and coastal areas are not doing conservation. Different physical circumstances, the conservation of watersheds and coastal forms differ. Socio-economic condition of farmer affect the conservation. The farmer could not reforestation conservation form, as the socio-economic needs. While in the farmer swamp and coastal conservation is not done, because the physical state was not possible. To conserve of Sagara Anakan, then the shape of coastal conservation by planting trees, not catch fish, marine dredging, not taking out the trash, do not use drugs to win the fish and catch a certain size. While in conservation should be done with different shape and performed in an integrated manner that requires the participation of the population.
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Van Bergen, Janneke, Jan Mulder, Steffen Nijhuis, Daan Poppema, Kathelijne Wijnberg und Mieke Kuschnerus. „Urban dunes“. Research in Urbanism Series 7 (18.02.2021): 101–28. http://dx.doi.org/10.47982/rius.7.130.
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Sandy shores worldwide suffer from coastal erosion due to a lack of sediment input and sea-level rise. In response, coastal sand nourishments are executed using ‘Building with Nature’ techniques (BwN), in which the sand balance is amplified and natural dynamics are instrumental in the redistribution of sand, cross- and alongshore. These nourishments contribute to the growth of beaches and dunes, serving various design objectives (such as flood safety, nature, and recreation). Nevertheless, human interference (such as buildings and traffic) along urbanized sandy shores may have significant, yet poorly understood, effects on beach and dune development. Better insight is required into the interplay of morphological, ecological and urban processes to support Aeolian BwN processes for dune formation and contribute to the sustainable design of urbanized coastal zones. This paper aims to bridge the gap between coastal engineering and urban design by formulating design principles for BwN along urbanized sandy shores, combining nourishments, natural dune formation and urban development on a local scale to strengthen the coastal buffer. The first part of the paper analyses sedimentation processes in the (built) sea-land interface and identifies spatial mechanisms that relate coastal occupation to dune formation. Hence a preliminary set of design principles is derived by manipulating wind-driven sediment transport for BwN dune formation after nourishment. In the second part of the paper, these principles are applied and contextualized in two case-studies to compare their capability for BwN in different coastal profiles: the vast, rural, geomorphologically high dynamic profile of a mega-nourishment (Sand Motor); versus the compact, highly urbanized, profile(s) of a coastal resort (Noordwijk). Conclusions reflect on the applicability of BwN design principles within different coastal settings (dynamics, urbanity) and spatial arrangements facilitating BwN dune formation.
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Naciri, Walid, Arnoud Boom, Matthew Payne, Nicola Browne, Noreen J. Evans, Philip Holdship, Kai Rankenburg et al. „Massive corals record deforestation in Malaysian Borneo through sediments in river discharge“. Biogeosciences 20, Nr. 8 (21.04.2023): 1587–604. http://dx.doi.org/10.5194/bg-20-1587-2023.
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Abstract. Logging of tropical primary forests is a widely acknowledged global issue threatening biodiversity hotspots and indigenous communities leading to significant land erosion and decreased soil stability. The downstream effects of logging on human coastal communities include poor water quality and increased sedimentation. Quantifying the impacts of historical deforestation within a watershed requires accurate data from river discharge or satellite images, which are rarely available prior to the 1980s. In the absence of these in situ measurements, proxies have successfully produced accurate, long-range, historical records of temperature, hydrological balance, and sediment discharge in coastal and oceanic environments. We present a 30-year, monthly resolved Ba/Ca proxy record of sediment in river discharge as measured from the skeletal remains of massive corals Porites sp. from northern Malaysian Borneo. We make the comparison with local instrumental hydrology data, river discharge and rainfall, to test the reliability of the Ba/Cacoral proxy. Our results show that averaging five records into two composites results in significant positive annual correlations with river discharge (r = 0.5 and r = 0.59) as well as a difference in correlation strength coherent with distance from the river mouth, with the composite closer to the river mouth displaying a higher correlation. More importantly, Ba/Cacoral records from this region showed a very similar upward trend to that of river discharge on multi-decennial timescales. The lack of similar increase and overall stability in the precipitation record suggests that the river discharge's trend recorded by corals is linked to the increasing land use associated with ever-growing deforestation. We argue that massive corals in this region are therefore valuable archives of past hydrological conditions and accurately reflect changes in land use patterns.
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ZABOKRYTSKA, M. R. „FIRST IN UKRAINE “HYDROLOGICAL DICTIONARY” WAS PUBLISHED (2022)“. Hydrology, hydrochemistry and hydroecology, Nr. 3(65) (2022): 128–32. http://dx.doi.org/10.17721/2306-5680.2022.3.10.
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The article presents and analyzes the explanatory “Hydrological Dictionary” published in 2022. Authors of the Dictionary: V.K. Khilchevskyi, V.V. Grebin (Taras Shevchenko National University of Kyiv), V.O. Manukalo (Ukrainian Hydrometeorological Institute of the State Emergency Service of Ukraine and the National Academy of Sciences of Ukraine). Hydrology is the science of the hydrosphere, which studies its properties, dynamics and interaction with other elements of the geographic envelope of the Earth. According to the objects under study, it is divided into hydrology. surface waters (or land hydrology), hydrology of oceans and seas (oceanology). In turn, the hydrology of surface waters is the hydrology of rivers (the study of rivers) and the hydrology of lakes (lake science or limnology). In water bodies, the following is studied: the dynamics of water masses (currents, waves, infiltration and other processes); dynamics of their bed (formation of banks and bottom of water bodies, channel processes, erosion, transport and sedimentation); thermal processes (heat exchange, heat balance, evaporation, water balance) and aggregate states of water (ice phenomena, snow cover), chemical and biological processes. The hydrology of groundwater (hydrogeology), the hydrology of soils, the hydrology of glaciers (glaciology) and the hydrology of swamps are also distinguished. Due to the commonality of the processes occurring in water bodies, along with the object-wise division of hydrology, it is often divided according to the processes studied into water dynamics, hydrophysics, hydrochemistry, and hydrobiology. Since these processes in each of the water bodies have their own characteristics, object disciplines have been developed in hydrology, including the study of a complex of issues in water dynamics, hydrophysics, hydrochemistry and hydrobiology. Since an ever wider range of specialists are involved in this area, including those who deal with the topical problem of the use, protection and reproduction of water resources, the issues of unification of hydrological terminology are becoming important. This goal is dedicated to the “Hydrological Dictionary”, which is the first in Ukraine scientific reference publication of this direction. The Dictionary includes more than 1600 terms and concepts that are widely used in the scientific literature on hydrology, as well as a number of terms in related scientific disciplines related to hydrology (hydrochemistry, geography, meteorology, geology, hydrogeology, hydrobiology, etc.). When working on the Dictionary, significant scientific and methodological experience of the scientific school of the Department of Hydrology and Hydroecology of the Faculty of Geography of Taras Shevchenko National University of Kyiv was used. The dictionary is designed for students of universities specializing in “Earth Sciences” of educational programs in the hydrological profile. The dictionary will be useful to specialists in the field of hydrology, hydroecology, hydrochemistry, hydrogeology, geography.
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Bogucka, Małgorzata, und Artur Magnuszewski. „The Sedimentation Processes in Włocławek Reservoir“. Miscellanea Geographica 12, Nr. 1 (01.12.2006): 95–101. http://dx.doi.org/10.2478/mgrsd-2006-0011.
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Abstract The study discusses accumulation and erosion processes which occurred in the bowl of Włocławek Reservoir in the period 1971-1992, and were analysed using digital batimetric maps. It also provides the results of the work of other authors concerning the assessment of the river sediments accumulated in the reservoir. Analysis of digital batimetric maps has shown that the material deposited in Włocławek Reservoir in the years 1971-1992 totalled about 18.3 million m3, which corresponds to approximately 0.87 million m3 of sediments per annum, and means a 4.5% loss of the reservoir’s storage capacity. The volume of accumulation and erosion, assessed in this manner, approximates the earlier calculations performed using different research methods; it corroborates the fact that accumulation prevails in the balance of the sediments.
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Peterson, Curt D., und Sandy Vanderburgh. „Interconnected Accommodation Space Controls Between Sand-Charged Shallow Tidal Channels and Wind-Wave Truncated Tidal Flats During Latest-Holocene Sea Level Rise (~3.0 m) in a Large Mesotidal Wave-Dominated Estuary, Grays Harbor, Washington, USA“. Journal of Geography and Geology 10, Nr. 3 (12.08.2018): 26. http://dx.doi.org/10.5539/jgg.v10n3p26.
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The late-Holocene (5–0 ka) record of accommodation space controls of tidal channel and tidal flat deposition in the shallow mesotidal wave-dominated Grays Harbor estuary (236 km2 surface area) was investigated in previously reported drill cores (n=15) and new vibracores (n=20), reaching 3–10 m depth subsurface. Continuous vibracore facies sequences (3–4 m depth subsurface) discriminate between tidal channel and tidal flat deposition and demonstrate responses of both depositional settings to interseismic uplift and coseismic subsidence (1±0.5 m vertical) from cyclic neotectonic forcing (200–800 yr recurrence intervals) in the Cascadia subduction zone. Vibracore channel samples, at 0.5 m or 1.0 m depth intervals, were analyzed for sediment grain size (sample n=124) and sand source mineralogy (sample n=67). The mean and standard deviation of sand size in the sand fraction is 175±x34 1σ µm. Sediment 14C dates (n=29) range from 376 to 6,579 median calyrBP and establish long-term sedimentation rates in subtidal channel accretionary banks (average 4.2 m ka-1), intertidal channel accretionary banks (average 3.7 m ka-1), and tidal flats (average 1.1 m ka-1). Tidal channel accretionary bank deposition largely reflects reworking of pre-existing estuary deposits. Long-term total basin sediment accumulation rates (232x106 m3 ka-1) are tied to rates of net sea level rise (1.0 m ka-1) or increasing basin accommodation space. In latest Holocene time (3–0 ka) littoral sand import (117x106 m3 ka-1) was about twice as large as the retention of river sand and mud in the estuary. The selective export of winnowed mud from the estuary provided the necessary accommodation space for the import of littoral sand in latest-Holocene time. Shallow intertidal settings in Grays Harbor (60% by surface area) are maintained by self-regulating conditions of channelized sediment import, wind-wave erosion of tidal flats, and tidal prism forcing of tidal channel discharge. Hind-casted wind-wave bottom orbital velocities (>20 cm sec-1) are sufficient to truncate tidal flat elevations to lower-intertidal levels, which maintain substantial tidal prism volumes (modern MLLW-MHHW ~6.1 x 108 m3) and associated tidal channel discharge in the shallow estuary. Net sediment deposition in the estuary is controlled by the interaction of limiting accommodation space controls in the tidal flats and tidal channels. The balance between sediment supply, energy of sediment transport/resuspension, and sediment export has survived small changes in relative sea level (1±0.5 m) from cyclic neotectonic forcing. However, the prehistoric (natural) balance could be altered by future anthropogenic impacts from sustained global sea level rise (> 1.5 m during the next century) or diminished wind-wave fetch distances, which could result from tidal flat diking/filling or uncontrolled spread of non-native invasive stabilizing sea grass (Spartina). In this regard, the susceptibilities of prehistorically-balanced sediment dynamics in Grays Harbor serve as warning for other similar mesotidal wave-dominated estuaries that could be impacted by future global sea level rise, changing sediment inputs, and/or tidal flat diking/filling, which could reduce intertidal habitat and associated ecosystem functions.
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Yang, Yan Hua, Xiao Qiang Liu und Hong Qian Zhang. „Research on Characteristics of New Water and Sediment of Yichang Station after Impoundment of the Three Gorges“. Advanced Materials Research 779-780 (September 2013): 1613–18. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.1613.
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Reservoir regulation and reservoir sedimentation make conditions of flow and sediment under the dam change greatly after impoundment of the Three Gorges Project. This paper analyzes change trend and abrupt change situation of incoming water and sediment and studies characteristics of new flow and sediment of Yichang Station after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method. The result indicates that operation of the Three Gorges Reservoir has leveled runoff process and shortened dry season and extended median water period. After operation of the Three Gorges Reservoir, annual sediment runoff and monthly sediment runoff of some months changed suddenly and sediment runoff reduced sharply in Yichang Station. Sediment entering the middle and the lower reaches of the Yangtze River decreases substantially and it almost can be regarded as clean water discharge. Intorduction After operation of 175m normal water level of the Three Gorges Reservoir, total storage capacity of the reservoir is about 43 billion m3. Most of incoming sediment in the upstream is intercepted and deposited inside the reservoir and clean water and muddy water containing non-bed sand discharges. Change of water and sediment conditions destroys balance of downstream river and causes bed-rebuilding of downstream channels. And this results in a serious of long-term and long distance changes, such as on-way recovery of sand content, undercutting of bed scour, expansion of bank erosion and decline of water table, etc.[1-. Yichang Station controls a drainage area of 1005501km2 in upstream of the Yangtze River and is a major flood source for the middle and the lower reach of the Yangtze River. Thus, water regime information of Yichang Station is significant to flood control of the middle and the lower reach of the Yangtze River, regulation of the Three Gorges Reservoir, construction of water conservancy project all across the Yangtze River, industrial and agricultural production and shipping, etc. On account of this, this article analyzes data about coming water and sediment of Yichang Station to support characteristics of new flow and sediment of Yichang Station after impoundment of the Three Gorges with Mann-Kendall nonparametric rank test method.
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Brocard, Gilles Y., Maud J. M. Meijers, Michael A. Cosca, Tristan Salles, Jane Willenbring, Christian Teyssier und Donna L. Whitney. „Fast Pliocene integration of the Central Anatolian Plateau drainage: Evidence, processes, and driving forces“. Geosphere 17, Nr. 3 (02.04.2021): 739–65. http://dx.doi.org/10.1130/ges02247.1.
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Abstract Continental sedimentation was widespread across the Central Anatolian Plateau in Miocene–Pliocene time, during the early stages of plateau uplift. Today, however, most sediment produced on the plateau is dispersed by a well-integrated drainage and released into surrounding marine depocenters. Residual long-term (106–107 yr) sediment storage on the plateau is now restricted to a few closed catchments. Lacustrine sedimentation was widespread in the Miocene–Pliocene depocenters. Today, it is also restricted to the residual closed catchments. The present-day association of closed catchments, long-term sediment storage, and lacustrine sedimentation suggests that the Miocene–Pliocene sedimentation also occurred in closed catchments. The termination of sedimentation across the plateau would therefore mark the opening of these closed catchments, their integration, and the formation of the present-day drainage. By combining newly dated volcanic markers with previously dated sedimentary sequences, we show that this drainage integration occurred remarkably rapidly, within 1.5 m.y., at the turn of the Pliocene. The evolution of stream incision documented by these markers and newly obtained 10Be erosion rates allow us to discriminate the respective contributions of three potential processes to drainage integration, namely, the capture of closed catchments by rivers draining the outer slopes of the plateau, the overflow of closed lakes, and the avulsion of closed catchments. Along the southern plateau margin, rivers draining the southern slope of the Central Anatolian Plateau expanded into the plateau interior; however, only a small amount of drainage integration was achieved by this process. Instead, avulsion and/or overflow between closed catchments achieved most of the integration, and these top-down processes left a distinctive sedimentary signal in the form of terminal lacustrine limestone sequences. In the absence of substantial regional climate wetting during the early Pliocene, we propose that two major tectonic events triggered drainage integration, separately or in tandem: the uplift of the Central Anatolian Plateau and the tectonic completion of the Anatolian microplate. Higher surface uplift of the eastern Central Anatolian Plateau relative to the western Central Anatolian Plateau promoted more positive water balances in the eastern catchments, higher water discharge, and larger sediment fluxes. Overflow/avulsion in some of the eastern catchments triggered a chain of avulsions and/or overflows, sparking sweeping integration across the plateau. Around 5 Ma, the inception of the full escape of the Anatolian microplate led to the disruption of the plateau surface by normal and strike-slip faults. Fault scarps partitioned large catchments fed by widely averaged sediment and water influxes into smaller catchments with more contrasted water balances and sediment fluxes. The evolution of the Central Anatolian Plateau shows that top-down processes of integration can outcompete erosion of outer plateau slopes to reintegrate plateau interior drainages, and this is overlooked in current models, in which drainage evolution is dominated by bottom-up integration. Top-down integration has the advantage that it can be driven by more subtle changes in climatic and tectonic boundary conditions than bottom-up integration.
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Kiesel, Jens, Britta Schmalz, Gary L. Brown und Nicola Fohrer. „Application of a hydrological-hydraulic modelling cascade in lowlands for investigating water and sediment fluxes in catchment, channel and reach“. Journal of Hydrology and Hydromechanics 61, Nr. 4 (01.12.2013): 334–46. http://dx.doi.org/10.2478/johh-2013-0042.
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Abstract This study shows a comprehensive simulation of water and sediment fluxes from the catchment to the reach scale. We describe the application of a modelling cascade in a well researched study catchment through connecting stateof- the-art public domain models in ArcGIS. Three models are used consecutively: (1) the hydrological model SWAT to evaluate water balances, sediment input from fields and tile drains as a function of catchment characteristics; (2) the onedimensional hydraulic model HEC-RAS to depict channel erosion and sedimentation along a 9 km channel onedimensionally; and (3) the two-dimensional hydraulic model AdH for simulating detailed substrate changes in a 230 m long reach section over the course of one year. Model performance for the water fluxes is very good, sediment fluxes and substrate changes are simulated with good agreement to observed data. Improvement of tile drain sediment load, simulation of different substrate deposition events and carrying out data sensitivity tests are suggested as future work. Main advantages that can be deduced from this study are separate representation of field, drain and bank erosion processes; shown adaptability to lowland catchments and transferability to other catchments; usability of the model’s output for habitat assessments.
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Carrillo, Emilio, Andrés Mora, Richard A. Ketcham, Ricardo Amorocho, Mauricio Parra, Diego Costantino, Wilmer Robles et al. „Movement vectors and deformation mechanisms in kinematic restorations: A case study from the Colombian Eastern Cordillera“. Interpretation 4, Nr. 1 (01.02.2016): T31—T48. http://dx.doi.org/10.1190/int-2015-0049.1.
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We have developed a new method to assess the movement of particles in different steps of a well-calibrated sequential kinematic restoration. Calibration included correct assessment of amounts of overburden, sedimentation, erosion, and thermal behavior through time. Our method allowed a better understanding of the mechanisms of deformation and uplift in different geologic provinces. In our pilot case study in the Colombian Eastern Cordillera, we have used movement vectors in balanced cross sections to document an initial phase of dominant vertical uplift and a final phase of dominant tangential horizontal shortening. Our findings challenged the common assumptions related to folding and deformation mechanisms in fold-and-thrust belts used for cross-section balancing and palinspastic reconstructions. Thus, we found that the movement vectors in cross sections can be used to test and validate a complete procedure to obtain calibrated sequential kinematic restorations and represent a powerful tool to better understand deformation mechanisms in different settings.
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Finzel, Stephanie, Sebastian Kraus, Camille Pinto Figueiredo, Adrian Regensburger, Roland Kocijan, Juergen Rech und Georg Schett. „Comparison of the effects of tocilizumab monotherapy and adalimumab in combination with methotrexate on bone erosion repair in rheumatoid arthritis“. Annals of the Rheumatic Diseases 78, Nr. 9 (29.05.2019): 1186–91. http://dx.doi.org/10.1136/annrheumdis-2018-214894.
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ObjectiveTo compare the effects of interleukin-6 (IL-6) receptor and tumour necrosis factor inhibition on inducing repair of existing bone erosions in patients with very early rheumatoid arthritis (RA).MethodsProspective non-randomised observational study in patients with active erosive RA with inadequate response to methotrexate (MTX) receiving either tocilizumab (TOC) monotherapy or adalimumab (ADA) with MTX for 52 weeks. Erosion volumes were assessed in metacarpal heads (MCH) and the radius by high-resolution peripheral quantitative CT at baseline and after 52 weeks. Clinical response was monitored using Clinical Disease Activity Index, Simple Disease Activity Index and Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR) scores every 12 weeks.ResultsTOC (N=33) and ADA/MTX (N=33) treatment groups were balanced for age, sex, body mass index, comorbidities, disease and activity, functional state, autoantibody status, baseline bone damage and baseline bone biomarkers. Both TOC (DAS28-ESR: baseline: 6.2±0.5; 52 weeks: 2.3±1.0) and ADA/MTX (6.3±0.6; 2.8±1.2) significantly reduced disease activity. Erosion volumes significantly decreased in the MCH and radius of patients with RA treated with TOC (p<0.001) but not in patients treated with ADA/MTX (p=0.77), where they remained stable in size. Mean decrease in erosion volume in TOC-treated patients was −1.0±1.1 mm3 and −3.3±5.9 mm3 in the MCH and radius of TOC-treated patients, respectively, and −0.05±0.9 mm3 and −0.08±4.1 mm3 in patients treated with ADA/MTX.ConclusionsThe REBONE study shows that TOC monotherapy achieves more pronounced repair of existing bone erosions than ADA/MTX. Hence, IL-6 is a central factor for the disturbed bone homeostasis in the joints of patients with RA.
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Valent, Peter, Roman Výleta und Michaela Danáčová. „A Joint Sedimentation-Flood Retention Assessment of a Small Water Reservoir in Slovakia: A New Hope for Old Reservoirs?“ Geosciences 9, Nr. 4 (03.04.2019): 158. http://dx.doi.org/10.3390/geosciences9040158.
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The intensification of agricultural production brings problems related to water erosion, even to the upper parts of river basins. Soil particles that have eroded from unprotected agricultural land are often deposited in small water reservoirs, the efficiency or function of which might be compromised. This study presents an analysis of changes in the retention capacity of a small water reservoir over a period of 8 years. Within the study, a detailed bathymetry of the reservoir was conducted using an acoustic Doppler current profiler. The results, when compared to a 2008 geodetic survey, showed that the retention volume of the reservoir was reduced by only 2%, which was also confirmed by mathematical modeling. The possibility of strengthening the reservoir’s role in flood protection was also investigated. A flood wave with a return period of 100 years was estimated using a design storm approach. A simple numerical model was proposed to transform the flood wave through the reservoir by considering four different scenarios of the elevation of the initial water level. The model, which is based on a water balance equation, uses simple hydraulic relationships to control the discharge through the reservoir’s outflow objects. The results demonstrate that by reducing the initial water level, significant improvements in terms of the flood peak’s attenuation and a longer time to peak values could be achieved.
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Sallata, M. Kudeng, und Hunggul Nugroho. „Browse By Issue By Author By Title By Sections By Identify Types Other Journals KEYWORDS DAS Mikro DAS mikro USLE drought erosi erosion flood fuzzy-AHP jasa lingkungan land use landform landslide metode sidik cepat mitigation partisipasi pengelolaan DAS perencanaan prioritas sedimentation vulnerability watershed LANGUAGE Select Language English Journal Help NOTIFICATIONS View (340 new) Manage FONT SIZE INDEXED BY : MORE.... USER You are logged in as... jdassolo My Journals My Profile Log Out JOURNAL ACCREDITATION : SINTA 2 M E N U : EDITORIAL BOARD : JOURNAL TEMPLATE : VISITOR : StatCounter - Free Web Tracker and Counter View My Stats CITATION Citation = 173 H-index = 6 STATISTICS REFERENCE TOOL : ABOUT THE AUTHORS Markus Kudeng Sallata Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan Makassar Hunggul Yudono Setio Hadi Nugroho orcid https://www.scopus.com/authid/detail.uri?authorId=57194607752 Scopus ID: 57194607752, Hydrology and Soil Conservation, Watershed Management Technology Center (WMTC) Solo Indonesia ARTICLE TOOLS Print this article Indexing metadata How to cite item Email this article Email the author OPEN JOURNAL SYSTEMS INFORMATION For Readers For Authors For Librarians HOMEABOUTUSER HOMESEARCHCURRENTARCHIVESANNOUNCEMENTSPUBLICATION ETHICS Home > Vol 6, No 1 (2022) > Sallata PENGELOLAAN SUMBER DAYA AIR PARTISIPATIF DI WILAYAH HULU DAERAH ALIRAN SUNGAI BIALO, SULAWESI SELATAN (Participatory Water Resources Management in the Bialo Upstream Watershed, South Sulawesi)“. Jurnal Penelitian Pengelolaan Daerah Aliran Sungai 6, Nr. 1 (01.04.2022): 57–76. http://dx.doi.org/10.20886/jppdas.2026.6.1.57-76.
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Poor watershed management has resulted in environmental degradation and has resulted in increasingly competitive use of water resources. The balance between demand and supply of water in the upstream watershed area as a water recharge area becomes difficult to obtain. The main parties most affected are the poor in the upstream watershed. This research was carried out in two villages in Bulukumba Regency and Bantaeng Regency, South Sulawesi with the aim of producing an effective and efficient residential-based independent water resource management model in the upstream watershed that ensures a balance between demand and sustainable supply. The participatory action research (PAR) method is used as an approach in conducting research. PAR prioritizes participatory action, assessment, and learning through regular mentoring to encourage interactive community participation. In describing the general condition of the research location, qualitative descriptive analysis was used. Domestic water supply and demand are calculated based on the number and rate of population growth. The results showed that the settlement-based water management model in the two villages was able to produce water that exceeds the need and in sufficient quantity and quality in a sustainable manner. From the process of implementing the activities for 3 years, it can be seen that the PAR approach with mentoring has an impact on increasing the community's ability, self-confidence, and increasing their motivation to manage their natural resources better together. The PAR process also triggers an increase in public perception and trust in assistance from outside parties so that subsequent programs are more easily accepted by the community.
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Azizah, D., F. Lestari, Susiana, D. Kurniawan, W. R. Melany, T. Apriadi und S. Murtini. „Index of environmental pollution and adaptation of Avicennia marina around the ex-bauxite mining area in Bintan Island“. IOP Conference Series: Earth and Environmental Science 967, Nr. 1 (01.01.2022): 012016. http://dx.doi.org/10.1088/1755-1315/967/1/012016.
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Abstract Bintan Island has high bauxite resource potential. However, its utilization is not balanced with efforts to restore ex-mining land. Physical damage includes erosion and sedimentation of red mud along the coast and the surrounding mangrove forest. This study aims to determine environmental pollution based on the accumulation of lead (Pb) and chromium (Cr) in redmud found in mangrove forests around the bauxite ex-mining area and the adaptation of Avicennia marina to heavy metals. This research was conducted from April to December 2020. Research survey and laboratory analysis using Atomic Absorban Spectrophotometry. The results showed that Pb in the sediments and organs of A. marina was higher than Cr. The results showed that the mangrove forest around the bauxite ex-mining area of Bintan Island was contaminated with low levels of Pb and Cr metals (CF<1, PLI<1) and the environment is lightly polluted (0<Igeo<1). Adaptation of A. marina showed that the metal uptake mechanism was rhizofiltration (BCF<1, TF<1, BCF<TF) and the physical condition was slightly damaged. There was no significant effect between Pb and Cr metals in the sediments and organs of A. marina on the stem diameter and tree height (Sig.> 0.05).
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Owens, Philip N. „Soil erosion and sediment dynamics in the Anthropocene: a review of human impacts during a period of rapid global environmental change“. Journal of Soils and Sediments 20, Nr. 12 (04.11.2020): 4115–43. http://dx.doi.org/10.1007/s11368-020-02815-9.
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Abstract Purpose Humanity has been modifying the planet in a measurable way for thousands of years. Recently, this influence has been such that some feel we are in a new geological epoch, the Anthropocene. This review will describe how soil erosion and sediment dynamics have (i) been used to assess the impact of humans on the planet and (ii) affected the global climate and influenced water security. Emphasis is placed on changes since the middle of the twentieth century, as this coincides with what many suggest is the start of the Anthropocene Epoch. Results and discussion The use of sediment archives has been instrumental in our understanding of how environmental systems have developed over time, both naturally and in response to anthropogenic activities. Additional information has come from measurement and monitoring programs, and tracing and fingerprinting studies. In turn, models have been developed that enable forecasting. Some of the main global impacts of enhanced soil erosion and changes in sediment dynamics and sediment composition include: changes in radiative energy balances and impacts on the cryosphere; the global carbon cycle; and greenhouse gas emissions. Impacts on water security include: effects on freshwater biota, including wild salmon populations; fluxes of contaminants, including microplastics; and reservoir and river channel sedimentation, including flooding. Sediment archives and monitoring programs have also been used to document the effect of mitigation measures and environmental policies. Conclusion Sediment archives enable us to assemble information over a variety of timescales (i.e., 100 to 105 years and longer) and a range of spatial scales (from sub-watershed to continental), in addition to environments ranging from arid to tropical to polar. Often the temporal resolution is better than other paleoenvironmental reconstruction approaches. As such, sedimentary records, when combined with measurement and monitoring approaches and other sources of information, have enabled us to determine changes in atmospheric, terrestrial, and aquatic systems, especially over the last 100 years. While soil erosion and sediment dynamics have provided a wealth of information and greatly enhanced our understanding of the role of humanity in modifying the planet, suggestions are given for further research.
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Hermansyah, Hermansyah, Yuningsih Lulu, Ibrahim Eddy und Marsi Marsi. „ANALYSIS ON THE CHARACTERISTICS OF EX-MINING SOIL AFTER 5 YEARS AND 10 YEARS OF REVEGETATION“. Media Konservasi 26, Nr. 3 (17.01.2022): 239–47. http://dx.doi.org/10.29244/medkon.26.3.239-247.
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Open-pit mining has affected landscapes and ecosystem balances immensely. The effects are including altered soil surface, decreased soil productivity, soil compaction, erosion and sedimentation, declined biodiversity, as well as deteriorated hydrological, hydrogeological, and atmospheric function of the surrounding area. Reclamation is one of the environmental restoration efforts that could be taken to improve these conditions. Physical and chemical properties of soil are the indicators of soil damage level as well as the success indicator of the reclamation program. This study aims to analyze the changes in post-mining soil characteristics after 5 years and 10 years of revegetation. The sample was selected by the purposive sampling method based on the age of plants and the vegetation density. The physical properties of post-coal soil after 5 years of revegetation are characterized by high soil acidity, low in organic matter (OM)/soil organic carbon (SOC), very low total N (nitrogen), moderate P availability, extremely high K2O, and moderate CEC. Whilst, the post-coal mining soil after 10 years of revegetation is found to be acidic (low pH), with moderate SOC, low total N, low P, very high K2O, and moderate CEC. Heavy metal (Fe, Mn, Al) contents in ex-coal mining reclamation area after 5 years and 10 years revegetation found to be in the high category.
Key words: post-mining land, revegetation, soil characteristics