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

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.

2015 ◽  
Vol 737 ◽  
pp. 762-765 ◽  
Author(s):  
Yuan Yuan Han ◽  
Tao Cai

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.


2018 ◽  
Vol 10 (3) ◽  
pp. 851 ◽  
Author(s):  
Katherine Merriman ◽  
Amy Russell ◽  
Cynthia Rachol ◽  
Prasad Daggupati ◽  
Raghavan Srinivasan ◽  
...  

Subwatersheds within the Great Lakes “Priority Watersheds” were targeted by the Great Lakes Restoration Initiative (GLRI) to determine the effectiveness of the various best management practices (BMPs) from the U.S. Department of Agriculture-Natural Resources Conservation Service National Conservation Planning (NCP) Database. A Soil and Water Assessment Tool (SWAT) model is created for Alger Creek, a 50 km2 tributary watershed to the Saginaw River in Michigan. Monthly calibration yielded very good Nash–Sutcliffe efficiency (NSE) ratings for flow, sediment, total phosphorus (TP), dissolved reactive phosphorus (DRP), and total nitrogen (TN) (0.90, 0.79, 0.87, 0.88, and 0.77, respectively), and satisfactory NSE rating for nitrate (0.51). Two-year validation results in at least satisfactory NSE ratings for flow, sediment, TP, DRP, and TN (0.83, 0.54, 0.73, 0.53, and 0.60, respectively), and unsatisfactory NSE rating for nitrate (0.28). The model estimates the effect of BMPs at the field and watershed scales. At the field-scale, the most effective single practice at reducing sediment, TP, and DRP is no-tillage followed by cover crops (CC); CC are the most effective single practice at reducing nitrate. The most effective BMP combinations include filter strips, which can have a sizable effect on reducing sediment and phosphorus loads. At the watershed scale, model results indicate current NCP BMPs result in minimal sediment and nutrient reductions (<10%).


Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 963-978 ◽  
Author(s):  
L. Palazón ◽  
L. Gaspar ◽  
B. Latorre ◽  
W. H. Blake ◽  
A. Navas

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.


2020 ◽  
Vol 1 (2) ◽  
pp. 36-42
Author(s):  
Kamel Khanchoul ◽  
Amina Amamra ◽  
Bachir Saaidia

Erosion is identified as one of the most significant threats to land in increasing rates of soil loss and reservoir sedimentation. An integrated approach therefore requires sediment assessment for identification of its sources for efficient watershed management. The present study is aimed to examine the spatial and temporal sediment yield distribution potential and to identify the critical erosion prone zones within Kebir watershed, Algeria using Soil and Water Assessment Tool interfaced in GIS for the period from 1982 to 2014. The model is calibrated by adjusting sensitive parameters and validation is done using observed data from 1982 to 1998. The model performance checked by the coefficient of determination (0.76), Nash–Sutcliffe coefficient (0.75) and relative error (+8.19%) suggests that the model has performed satisfactorily for sediment yield prediction. The simulated outputs of the model show that the 33-year period of sediment load production is estimated to be 19.24×106 tons and a mean annual sediment yield of 856.14 T/km²/yr. Temporally, sixty-four percent (50%) of sediment yield generated in the watershed occurs in five months of the winter and fall seasons. The most erosion vulnerable sub-basins that could have a significant impact on the sediment yield of the reservoirs are identified. Based on this, sub-basin 16, 14, 13, 11 and 8 are found to be the most erosion sensitive areas that could have a significant contribution, of 50%, to the increment of sediment yield. Best management practices are highly recommended for the land sustainability because of the high sediment supply to the dams.


2011 ◽  
Vol 2 (2) ◽  
pp. 23-34
Author(s):  
Oon Y.W. ◽  
Chin N.J. ◽  
Law P.L.

 This research presents the results of a study on soil erosion rates and sediment yields of a proposed Level 4 Sanitary Landfill construction site located in Sibu, Sarawak. Assessments on potential soil erosion rates and sediment yields during pre-construction, construction and operation stages were carried out using the Revised Universal Soil Loss Equation (RUSLE) and Modified Universal Soil Loss Equation (MUSLE), respectively. It was found that soil erosion rates during construction and operation stages fell under "Moderately High" category, whereby highest sediment yield occurred during construction and operation stages. Comparative analysis on with and without Best Management Practices (BMPs) during construction stage demonstrated that BMPs could significantly reduce the rate of soil erosion, and thus sediment yields.


2020 ◽  
Vol 63 (2) ◽  
pp. 513-522 ◽  
Author(s):  
Ritesh Karki ◽  
Puneet Srivastava ◽  
Tamie L. Veith

HighlightsThis review study identified five different ways of setting up a SWAT model for field-scale analysis.Model setup for each field-scale modeling method and examples of application are discussed.Benefits and limitations of each method are discussed.Abstract. Although the Soil and Water Assessment Tool (SWAT) has been widely used as a watershed/basin scale model, recently there has been considerable interest in applying it at the field scale, especially for evaluation of best management practices and for building stakeholder confidence. In this study, a thorough review of the literature on field-scale application of SWAT was conducted. It was determined that there is more than one way of setting up a field-scale SWAT model depending on the spatial scale of the research as well as the research question to be answered. This article provides a detailed review of the methods used for field-scale SWAT modeling along with a summary of applications. This article also discusses the limitations and advantages of each method along with future research needs. The overarching goal of this article is to provide a valuable and time-conserving resource for future researchers interested in field-scale SWAT modeling. Keywords: Arc-SWAT, Field level, Field-scale resolution, Field-scale SWAT, SWAT.


2021 ◽  
Author(s):  
Hamza Briak ◽  
Rachid Moussadek ◽  
Khadija Aboumaria ◽  
Fassil Kebede ◽  
Rachid Mrabet

&lt;p&gt;Recent studies on vulnerability to climate and land use change show a trend towards increased aridity accelerating soil erosion which is the primary factor to be considered by decision makers in the environmental field. Furthermore, to reduce the soil erosion intensity, it is required to clarify the sources zones of sediment yield where soil conservation works have to focus on. The model selected for this work is the Soil and Water Assessment Tool (SWAT) which is one of many models widely used to assess soil erosion risk and simulate conservation measures efficiency. In fact, the objective of this work is to evaluate the effects of different agricultural Best Management Practices (BMPs) on sediments using SWAT model in the Kalaya river basin located in the North of Morocco in order to recommend the most appropriate one. The model was calibrated and validated using observed data of flow and sediment concentration; the performance of the model was evaluated using statistical methods and the total soil erosion rate was estimated by this model in the study area. However, we concentrated on the representation of three interesting and most usable practices by the SWAT model: contouring, strip-cropping and terracing. The general parameters of the model have been modified to reflect the implementation of four different BMPs. The modification of these parameters was based on previous research and modeling efforts conducted in watersheds. Resulting sediment yield were compared with the result of simulation of the baseline scenario (existing conditions). In fact, effective measures to reduce sediment losses at the watershed level are organized according to their effectiveness, and these are terracing (28% reduction and the value is 15t/ha/y) followed by strip-cropping (9% reduction and the value is 5t/ha/y). On the other hand, measurements performed by the contouring are inappropriate for the study area because they have contributed to increasing the soil erosion (more than 31% of losses and the value is 17t/ha/y more than existing conditions). The mean annual values of sediment yields obtained for scenarios with and without BMPs were compared to assess the effectiveness of BMPs. Among all other practices, terracing was the most effective BMPs for reducing sediments which is perfectly recommended in the Mediterranean regions in general to avoid the risk of damage during intense rainfall. These results indicates that the use of terracing on agricultural land can potentially make improvements marked the control and limitation of soil erosion, and it also affords useful information for involved stakeholders in water and soil conservation activities for targeted management.&lt;/p&gt;


SIMULATION ◽  
2011 ◽  
Vol 88 (3) ◽  
pp. 365-380 ◽  
Author(s):  
Margaret W Gitau ◽  
Li-Chi Chiang ◽  
Mohamed Sayeed ◽  
Indrajeet Chaubey

Models are increasingly being used to quantify the effects of best management practices (BMPs) on water quality. While these models offer the ability to study multiple BMP scenarios, and to analyze impacts of various management decisions on watershed response, associated analyses can be very computationally intensive due to a large number of runs needed to fully capture the various uncertainties in the model outputs. There is, thus, the need to develop suitable and efficient techniques to handle such comprehensive model evaluations. We demonstrate a novel approach to accomplish a large number of model runs with Condor, a distributed high-throughput computing framework for model runs with the Soil and Water Assessment Tool (SWAT) model. This application required more than 43,000 runs of the SWAT model to evaluate the impacts of 172 different watershed management decisions combined with weather uncertainty on water quality. The SWAT model was run in the Condor environment implemented on the TeraGrid. This framework significantly reduced the model run time from 2.5 years to 18 days and enabled us to perform comprehensive BMP analyses that may not have been possible with traditional model runs on a few desktop computers. The Condor system can be used effectively to make Monte Carlo analyses of complex watershed models requiring a large number of computational cycles.


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