scholarly journals A review of radiometric analysis on soil erosion and deposition studies in Africa

2018 ◽  
Vol 45 (1) ◽  
pp. 10-19 ◽  
Author(s):  
Caroline W. Maina ◽  
Joseph K. Sang ◽  
Benedict M. Mutua ◽  
James M. Raude
Keyword(s):  
Soil Erosion ◽  
Storage Capacity ◽  
Sediment Cores ◽  
Sustainable Use ◽  
Soil Productivity ◽  
Reservoir Sedimentation ◽  
Erosion And Deposition ◽  
Reservoir Storage ◽  
Fallout Radionuclides ◽  
Capacity Loss

Abstract Soil erosion is one of the main soil degradation phenomena that threaten sustainable use of soil productivity thus affecting food security. In addition, it leads to reservoir storage capacity loss because of sedimentation. This not only affects water quantity but also water quality. Worldwide, annual loss in reservoir storage capacity due to sedimentation is 0.5 to 1%. Similarly, about 27% of land in Africa is largely degraded by erosion. As a result, there is need to minimize soil erosion and deposition through site specific estimation of soil erosion and deposition rates in the reservoirs. To achieve this, Fallout RadioNuclides (FRNs) are some of the methods in use. The most common radionuclides include; 137Cs, 210Pb and 7Be. Only few countries in Africa have exploited these FRNs. In these countries, 137Cs has been largely exploited but in some regions, it has been reported to be below minimum detection limit. Using 137Cs and 210Pb, maximum reference inventory in Africa is found to be 1450 and 2602 Bq/m2, respectively. However, there is minimal application of 7Be within the continent. Also, very little has been done in Africa to assess chronology and sedimentation rates of reservoirs using FRNs measured from sediment cores. In conclusion, a gap still exists on FRNs application in Africa in assessing soil erosion, deposition and reservoir sedimentation.

Assessment of Reservoir Storage Capacity Loss and Investigating the Effects of Climate Variability on Reservoir Sedimentation in Italy

2021 ◽  
Author(s):  
Epari Ritesh Patro ◽  
Carlo De Michele
Keyword(s):  
Soil Erosion ◽  
Hydrological Modeling ◽  
Sediment Load ◽  
Storage Capacity ◽  
Assessment Tool ◽  
Hydropower Plant ◽  
Reservoir Sedimentation ◽  
Capacity Loss ◽  
Starting Point ◽  
The Future

<p>Reservoir sedimentation has a prominent impact on the hydropower performance in the future and is a growing concern for hydropower stakeholders. Sedimentation caused by soil erosion is influenced by various parameters. Reservoir sedimentation is one of the most challenging problems that affect hydroelectric production since it overall causes a reduction of the reservoir capacity that overcomes the annual increase in storage volume and implies a dangerous net loss of energy. The first part of this study examined various Italian reservoirs (50 dams) to determine sedimentation rates and storage capacity loss based on available bathymetric surveys. All the reservoirs studied here have reached an average age of 74 years as of 2019, with the highest loss of capacity observed at 90% and the highest annual sediment yield of 2471 m<sup>3</sup>/km<sup>2</sup>/year. Out of all the reservoirs studied, 25% of them already have reached their half-life as of 2019. The second part of this study extended the work to the specific case study of the Ceppo Morelli hydropower plant. The study was carried out to analyse the water-sediment interaction, future sediment load and prioritizing of critical soil erosion areas using the Soil and Water Assessment Tool (SWAT). The distinguishing feature of this work lies in the possibility to exploit remote sensing data (i.e. actual/potential evapotranspiration) to successfully calibrate hydrological models in scarce data regions. Simulation results indicated that the discharge and sediment load entering Ceppo Morelli reservoir will decline and the rate of reduction of latter is higher than that of former for all the future climate scenarios implemented. This analysis will provide a starting point for management and prioritization of adaptation and remediation policies for addressing the issue of reservoir sedimentation. These results are part of the RELAID project funded through PRIN-Italy. The aim of this project is to integrate updated knowledge on hydrologic, hydraulics, and sedimentation processes to address the water and flood risk management of impounded Italian rivers through a holistic paradigm.</p><p>Keywords: reservoir sedimentation; hydropower; hydrological modeling; RELAID; Italy</p>

scholarly journals Estimating Reservoir Sedimentation at Large Dams in India

2018 ◽  
Vol 40 ◽  
pp. 03042
Author(s):  
David C. Froehlich
Keyword(s):  
Surface Runoff ◽  
Land Surface ◽  
Catchment Area ◽  
Storage Capacity ◽  
Reservoir Sedimentation ◽  
Capacity Loss ◽  
Large Dams ◽  
Mathematical Expressions ◽  
Storage Volume ◽  
Runoff And Sediment Yield

Mathematical expressions are developed that relate the storage capacity loss of reservoirs in India to the catchment area, the reservoir surface area, the original storage volume, and the time since the first filling of the impoundment. The relations for sedimentation of reservoirs found on eastward and westward flowing rivers differ significantly, because of meteorological and geological influences on land surface runoff and sediment yield within reservoir catchments. The formulations give good fits to the assembled data and allow an uncomplicated calculation of the half-life of reservoirs (that is, the time needed for the storage capacity to be reduced by 50%), which offers a measure of when sedimentation will have a significant adverse impact on the functioning of dams.

scholarly journals Effects of Sedimentation on Small Reservoirs in the Mushibemba Catchment, Mkushi Farm Block, Central Zambia

2019 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
Goodfellow Mphande ◽  
Henry M. Sichingabula
Keyword(s):  
Agricultural Land ◽  
Storage Capacity ◽  
Differential Gps ◽  
Reservoir Water ◽  
Reservoir Storage ◽  
Resources Management ◽  
Small Reservoirs ◽  
Capacity Loss ◽  
High Turbidity ◽  
Initial Storage

Sedimentation is one of the problems that affects the storage capacity of most small reservoirs, and if not addressed on time it may lead to the dams being filled up with sediment. The aim of this study was to assess the effects of sedimentation on the storage capacity losses of Moffat dam and GRZ Weir located in the Mushibemba Catchment of Mkushi Farm Block, Central Zambia. The method used to understand reservoir storage capacity loss was bathymetry survey using the hydrographic survey boat (RC-S2) which consists of an echo sounder and a Differential GPS. Information on the initial storage capacity of the two reservoirs was obtained from the Water Resources Management Authority (WARMA). The analysis of the data revealed that the measured volumes of Moffat dam and GRZ Weir were 1,180,462 m3 and 197,218 m3, respectively. The estimated storage capacity losses for Moffat reservoir was found to be 223,789 m³ and 53,312 m3 for the GRZ Weir.  The estimated rates of sedimentation loss were found to be 13,986.81 m3 yr-1 (Moffat reservoir), with a lifespan of 84 years, and 1,480.89 m3 yr-1 (GRZ Weir) with a lifespan of 133 years. The source of the accumulated sediment was mainly attributed to originate from the cleared commercial agricultural land which predominantly consists of clayey to loamy soils. This also accounted for the high turbidity of the reservoir water. This situation therefore calls for periodic dredging of the deposited sediment to increase reservoir storage capacity.

scholarly journals Simulating the Impact of Future Land Use and Climate Change on Soil Erosion and Deposition in the Mae Nam Nan Sub-Catchment, Thailand

2013 ◽  
Vol 5 (8) ◽  
pp. 3244-3274 ◽  
Author(s):  
Pheerawat Plangoen ◽  
Mukand Babel ◽  
Roberto Clemente ◽  
Sangam Shrestha ◽  
Nitin Tripathi
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Soil Erosion ◽  
Erosion And Deposition ◽  
The Impact

scholarly journals Sediment Yield and Soil Loss Estimation Using GIS Based Soil Erosion Model: A Case Study in the MAN Catchment, Madhya Pradesh, India

2021 ◽  
Vol 8 (1) ◽  
pp. 26
Author(s):  
Manti Patil ◽  
Radheshyam Patel ◽  
Arnab Saha
Keyword(s):  
Spatial Distribution ◽  
Soil Erosion ◽  
Soil Loss ◽  
Crop Production ◽  
Erosion Rate ◽  
Agricultural Land ◽  
Reservoir Sedimentation ◽  
Reservoir Water ◽  
Slope Length ◽  
Soil Erosion Rate

Soil erosion is one of the most critical environmental hazards of recent times. It broadly affects to agricultural land and reservoir sedimentation and its consequences are very harmful. In agricultural land, soil erosion affects the fertility of soil and its composition, crop production, soil quality and land quality, yield and crop quality, infiltration rate and water holding capacity, organic matter and plant nutrient and groundwater regimes. In reservoir sedimentation process the consequences of soil erosion process are reduction of the reservoir capacity, life of reservoir, water supply, power generation etc. Based on these two aspects, an attempt has been made to the present study utilizing Revised Universal Soil Loss Equation (RUSLE) has been used in integration with remote sensing and GIS techniques to assess the spatial pattern of annual rate of soil erosion, average annual soil erosion rate and erosion prone areas in the MAN catchment. The RUSLE considers several factors such as rainfall, soil erodibility, slope length and steepness, land use and land cover and erosion control practice for soil erosion prediction. In the present study, it is found that average annual soil erosion rate for the MAN catchment is 13.01-tons/ha/year, which is higher than that of adopted and recommended values for the project. It has been found that 53% area of the MAN catchment has negligible soil erosion rate (less than 2-tons/ha/year). Its spatial distribution found on flat land of upper MAN catchment. It has been detected that 26% area of MAN catchment has moderate to extremely severe soil erosion rate (greater than 10-tons/ha/year). Its spatial distribution has been found on undulated topography of the middle MAN catchment. It is proposed to treat this area by catchment area treatment activity.

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