scholarly journals Soil Erosion Modelling and Risk Assessment in Data Scarce Rift Valley Lake Regions, Ethiopia

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1684 ◽  
Author(s):  
Alemu Aga ◽  
Bayou Chane ◽  
Assefa Melesse
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Slope Length ◽  
Erosion Risk ◽  
Management Plans ◽  
Erosion Modelling ◽  
Lakes And Reservoirs ◽  
Bathymetric Changes

To prolong the useful life of lakes and reservoirs, prioritizing watersheds by severity and risk of soil erosion is an essential index to develop sound sediment management plans. This study aims to predict soil erosion risk and sediment yield using Soil and Water Assessment Tool (SWAT) model in Lake Ziway basin, Ethiopia, and the model result is validated with lake bathymetric changes. The SUFI-2 program was applied for a model calibration and the performance of the model was assessed. The catchment prioritization study indicated that some sub-basins having the same soil type and land use but a higher slope gives higher sediment yield. This confirms that, in the basin, the upland is the main source of sediment for the lake, hence the variation of sediment yield is more sensitive to terrain slope. Furthermore, the soil conservation scenarios demonstrated in SWAT that reduce the slope length of the watershed by 50% for a slope greater than 5% are decreasing the sediment yield of the basin by 55%. The bathymetric differencing of the lake indicates that the sediment was accumulating at a rate of 3.13 t/ha/year while a calibrated SWAT model resulted in 5.85 t/ha/year. The identified reasons for these variations are the existence of outlet for the lake, floodplain depositions and abstraction of sediment (sand mining) from the tributary rivers before flowing to the lake.

scholarly journals Prioritization of Sub-Watersheds to Sediment Yield and Evaluation of Best Management Practices in Highland Ethiopia, Finchaa Catchment

Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Wakjira Takala Dibaba ◽  
Tamene Adugna Demissie ◽  
Konrad Miegel
Keyword(s):  
Soil Erosion ◽  
Best Management Practices ◽  
Sediment Yield ◽  
Soil Loss ◽  
Crop Production ◽  
Management Practices ◽  
Assessment Tool ◽  
Swat Model ◽  
Sediment Yields ◽  
Soil And Water

Excessive soil loss and sediment yield in the highlands of Ethiopia are the primary factors that accelerate the decline of land productivity, water resources, operation and function of existing water infrastructure, as well as soil and water management practices. This study was conducted at Finchaa catchment in the Upper Blue Nile basin of Ethiopia to estimate the rate of soil erosion and sediment loss and prioritize the most sensitive sub-watersheds using the Soil and Water Assessment Tool (SWAT) model. The SWAT model was calibrated and validated using the observed streamflow and sediment data. The average annual sediment yield (SY) in Finchaa catchment for the period 1990–2015 was 36.47 ton ha−1 yr−1 with the annual yield varying from negligible to about 107.2 ton ha−1 yr−1. Five sub-basins which account for about 24.83% of the area were predicted to suffer severely from soil erosion risks, with SY in excess of 50 ton ha−1 yr−1. Only 15.05% of the area within the tolerable rate of loss (below 11 ton ha−1yr−1) was considered as the least prioritized areas for maintenance of crop production. Despite the reasonable reduction of sediment yields by the management scenarios, the reduction by contour farming, slope terracing, zero free grazing and reforestation were still above the tolerable soil loss. Vegetative contour strips and soil bund were significant in reducing SY below the tolerable soil loss, which is equivalent to 63.9% and 64.8% reduction, respectively. In general, effective and sustainable soil erosion management requires not only prioritizations of the erosion hotspots but also prioritizations of the most effective management practices. We believe that the results provided new and updated insights that enable a proactive approach to preserve the soil and reduce land degradation risks that could allow resource regeneration.

The Impacts of Land-Use Change Patterns on Soil Erosion in the Xixian Basin, China

2015 ◽  
Vol 737 ◽  
pp. 762-765 ◽  
Author(s):  
Yuan Yuan Han ◽  
Tao Cai
Keyword(s):  
Land Use ◽  
Time Series ◽  
Soil Erosion ◽  
Land Use Change ◽  
Sediment Yield ◽  
Water Conservation ◽  
Assessment Tool ◽  
Swat Model ◽  
Huaihe River ◽  
Soil And Water

To investigate the impacts of land-use patterns on the sediment yield characteristics in the upper Huaihe River, Xixian hydrological controlling station was selected as the case study site. Soil and Water Assessment Tool (SWAT) model was used to simulate land-use change effects on sediment yield by the use of three-phase (1980s, 1990s and 2000s) land-use maps, soil type map (1:200000) and 1987 to 2008 daily time series of rainfall from the upper Huaihe River basin. On the basis of the simulated time series of daily sediment concentration, land-use change effects on spatio-temporal change patterns of soil erosion modulus. The results revealed that under the same condition of soil texture and terrain slope the advantage for sediment yield was descended by woodland, paddy field and farmland. The outputs of the paper could provide references for soil and water conservation and river health protection in the upper stream of Huaihe River.

scholarly journals Evaluating the importance of surface soil contributions to reservoir sediment in alpine environments: a combined modelling and fingerprinting approach in the Posets-Maladeta Natural Park

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 963-978 ◽  
Author(s):  
L. Palazón ◽  
L. Gaspar ◽  
B. Latorre ◽  
W. H. Blake ◽  
A. Navas
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Sediment Fingerprinting ◽  
Sediment Yields ◽  
Resource Information ◽  
Erosion Processes ◽  
Natural Park ◽  
Alpine Environments

Abstract. Soil in alpine environments plays a key role in the development of ecosystem services and in order to maintain and preserve this important resource, information is required on processes that lead to soil erosion. Similar to other mountain alpine environments, the Benasque catchment is characterised by temperatures below freezing that can last from November to April, intense rainfall events, typically in spring and autumn, and rugged topography which makes assessment of erosion challenging. Indirect approaches to soil erosion assessment, such as combined model approaches, offer an opportunity to evaluate soil erosion in such areas. In this study (i) the SWAT (Soil and Water Assessment Tool) hydrological and erosion model and (ii) sediment fingerprinting procedures were used in parallel to assess the viability of a combined modelling and tracing approach to evaluate soil erosion processes in the area of the Posets-Maladeta Natural Park (central Spanish Pyrenees). Soil erosion rates and sediment contribution of potential sediment sources defined by soil type (Kastanozems/Phaeozems; Fluvisols and Cambisols) were assessed. The SWAT model suggested that, with the highest specific sediment yields, Cambisols are the main source of sediment in the Benasque catchment and Phaeozems and Fluvisols were identified as the lowest sediment contributors. Spring and winter model runs gave the highest and lowest specific sediment yield, respectively. In contrast, sediment fingerprinting analysis identified Fluvisols, which dominate the riparian zone, as the main sediment source at the time of sampling. This indicates the importance of connectivity as well as potential differences in the source dynamic of material in storage versus that transported efficiently from the system at times of high flow. The combined approach enabled us to better understand soil erosion processes in the Benasque alpine catchment, wherein SWAT identified areas of potential high sediment yield in large flood events but sediment fingerprinting identified areas that, due to high connectivity, contribute more to channel-stored sediment deposits.

scholarly journals Assessing the Impact of Man–Made Ponds on Soil Erosion and Sediment Transport in Limnological Basins

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2526
Author(s):  
Mario J. Al Sayah ◽  
Rachid Nedjai ◽  
Konstantinos Kaffas ◽  
Chadi Abdallah ◽  
Michel Khouri
Keyword(s):  
Sediment Transport ◽  
Soil Erosion ◽  
Assessment Tool ◽  
Swat Model ◽  
Erosion Risk ◽  
Sediment Yields ◽  
Risk Zones ◽  
Transport Patterns ◽  
Scientific Attention ◽  
The Impact

The impact of ponds on basins has recently started to receive its well-deserved scientific attention. In this study, pond-induced impacts on soil erosion and sediment transport were investigated at the scale of the French Claise basin. In order to determine erosion and sediment transport patterns of the Claise, the Coordination of Information on the Environment (CORINE) erosion and Soil and Water Assessment Tool (SWAT) models were used. The impact of ponds on the studied processes was revealed by means of land cover change scenarios, using ponded versus pondless inputs. Results show that under current conditions (pond presence), 12.48% of the basin corresponds to no-erosion risk zones (attributed to the dense pond network), while 65.66% corresponds to low-erosion risk, 21.68% to moderate-erosion risk, and only 0.18% to high-erosion risk zones. The SWAT model revealed that ponded sub-basins correspond to low sediment yields areas, in contrast to the pondless sub-basins, which yield appreciably higher erosion rates. Under the alternative pondless scenario, erosion risks shifted to 1.12%, 0.52%, 76.8%, and 21.56% for no, low, moderate, and high-erosion risks, respectively, while the sediment transport pattern completely shifted to higher sediment yield zones. This approach solidifies ponds as powerful human-induced modifications to hydro/sedimentary processes.

Sediment Yield Simulation Using SWAT Model for Water Environmental Protection in an Agricultural Watershed

2015 ◽  
Vol 713-715 ◽  
pp. 1894-1898
Author(s):  
Kai Xu ◽  
Hui Qing Peng ◽  
De Ge Ji Rifu ◽  
Rui Xin Zhang ◽  
Hao Xiao ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Environmental Protection ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Agricultural Watershed ◽  
Ecological Environment ◽  
Validation Period ◽  
Sediment Data ◽  
Water Assessment

Soil erosion in a catchment has becoming a serious environmental issue for an increasing damage to the surface ecological environment. To quantitatively simulate the sediment yield, the Soil and Water Assessment Tool (SWAT) was introduced in Tao River Basin. The investigation was conducted using a 8-year historical observed sediment data from 2001 to 2008. The performance evaluation shows that the simulated monthly sediment yield matched the observed data satisfactorily, with Re was less than 15%, R2 > 0.9 and Nash-suttclife (Ens)>0.8 for both calibration (2001-2004) and validation period (2005-2008) at two observed stations, indicating the validity of SWAT model for sediment yield simulation in the study area. The results of this study can be helpful for solving the soil erosion issue for water environmental protection.

scholarly journals Estimating sediment yield at Kaduna watershed, Nigeria using soil and water assessment tool (SWAT) model

Heliyon ◽  
2019 ◽  
Vol 5 (7) ◽  
pp. e02106 ◽  
Author(s):  
J. Daramola ◽  
T.M. Ekhwan ◽  
J. Mokhtar ◽  
K.C. Lam ◽  
G.A. Adeogun
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Water Assessment ◽  
Soil And Water

SWAT-based sediment yield simulation with mining land-use change scenario in Lanuza Bay, Philippines

2020 ◽  
Author(s):  
Peter Jeffrey Maloles ◽  
Adonis Gallentes ◽  
Cesar Villanoy
Keyword(s):  
Land Use ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Marine Protected Area ◽  
Swat Model ◽  
Time Lag ◽  
The Philippines ◽  
Marine Biodiversity ◽  
Change Scenario ◽  
Mining Operations

<p>The Philippines is known for its rich marine biodiversity and is deemed as the apex of the world’s coral triangle. However, sediment yield studies and river discharge measurements in the country are sparse if not non-existent. High sediment rates have detrimental effects on water quality and consequently to coral reef health and marine biodiversity. Thus, modeling of runoff and sediment yield at a watershed level is important in assessing coral community environments.</p><p>In this study, a Soil and Water Assessment Tool (SWAT) based sediment yield simulation was done for Lanuza Bay-- a site with high productivity but increasing mining activity. Two simulations were conducted. The first utilized a land-use map before January 2011 and was made to run from January 1998 to August 2018 in order to simulate a scenario in which mining operations did not occur in the area. The second simulation utilized an updated land-use map that incorporated mining sites from January 2011 to August 2018.</p><p>SWAT model results indicate that slope class was the primary determinant of erosion rates (slope band > 20%). The study suggests that consecutive precipitation occurrences affected soil erodability and induced a time lag between precipitation and sediment yield peaks. The highest contributors to sediment yield at a sub-basin level were identified to be areas adjacent to or coinciding in mining or excavation sites. Comparing the scenarios with and without mining, mining contributed to 4% of the increase in the watershed’s total annual sediment yield.</p><p>Qualitative and historical validation shows reasonable agreement between simulated values and satellite images. The output of this study can be used as a science-based reference in crafting laws and policies for land-use management and Marine Protected Area (MPA) planning.</p>

scholarly journals Spatio-temporal analysis of sediment yield with a physically based model for a data-scarce headwater in Konya Closed Basin, Turkey

2021 ◽  
Author(s):  
Cihangir Koycegiz ◽  
Meral Buyukyildiz ◽  
Serife Yurdagul Kumcu
Keyword(s):  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Temporal Analysis ◽  
Mathematical Methods ◽  
Closed Basin ◽  
Physically Based ◽  
Spatio Temporal ◽  
Sediment Data ◽  
Semi Empirical

Abstract There are many empirical, semi-empirical and mathematical methods that have been developed to estimate sediment yield by researchers. In the last decades, the advancement in computer technologies has increased the use of mathematical models as they can solve the system more rapidly and accurately. The Soil and Water Assessment Tool (SWAT) is one of the physically based hydrological models that is preferred to compute sediment yield. In this study, spatial and temporal analysis of sediment yield in the Çarşamba Stream located at the Konya Closed Basin has been investigated using the SWAT model. Streamflow and sediment data collected during the 2003–2015 time period have been used in the analysis. Consequently, the SWAT presented satisfactory results compared with R2 = 0.68, Nash–Sutcliffe Efficiency (NSE) = 0.68 in calibration and R2 = 0.76, NSE = 0.66 in validation. According to the model results, spatial asymmetry in terms of sediment yield was determined in the sub-basins of the study area.

Sign in / Sign up

Export Citation Format

Share Document