scholarly journals Optimizing micro watershed management for soil erosion control under various slope gradient and vegetation cover conditions using SWAT modeling

2017 ◽  
Author(s):  
Ghulam Nabi ◽  
Fiaz Hussain ◽  
Ray-Shyan Wu ◽  
Vinay Nangia ◽  
Riffat Bibi ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Watershed Management ◽  
Sediment Yield ◽  
Vegetation Cover ◽  
Soil Conservation ◽  
Swat Model ◽  
Yield Reduction ◽  
Slope Gradient ◽  
Soil And Water ◽  
Stone Structures

Abstract. This study evaluated parameters of soil erosion and optimization of micro watersheds by applying a semidistributed basin-scale Soil and Water Assessment Tool (SWAT) model in various small watersheds of the Chakwal and Attock districts of Pothwar, Pakistan. The model was calibrated and validated on a daily basis for a small catchment (Catchment-25) of the Dhrabi watershed without any soil conservation structures. Statistical measures (R2 and EN-S) were used to evaluate model performance; the model performed satisfactorily well for both surface runoff and sediment yield estimations, with the R2 and EN-S values both being greater than 0.75, during calibration (2009–2010) and validation (2011). The model was applied to various small watershed sites in the Chakwal and Attock districts after successful calibration and validation. Soil erosion estimation was performed at these sites having loose stone soil and water conservation structures and being under various slope gradient and vegetation cover conditions. The structures had significant effects, and the average sediment yield reduction engendered by the loose stone structures at the various sites varied from 54 to 98 %. The sediment yield and erosion reductions were also compared under conditions involving vegetation cover change. Agricultural land with winter wheat crops had a higher sediment yield level than did fallow land with crop residue, which facilitated sediment yield reduction along with the soil conservation structures. Analyzing various slope gradients revealed that all selected sites had a maximum slope area of less than 5 %; stone structures were installed at these sites to reduce sediment yield. Based on slope classification analysis, the model was upscaled for the whole districts of Chakwal and Attock. The results indicated that 60 % of Chakwal (4095 km2) and Attock (3918 km2) by area lies in a slope range of 0–4 %; this thus implies that considerable potential exists for implementing soil conservation measures by installing stone structures. Estimates revealed that minimum sediment yield reductions of 122,850 t year−1 in Chakwal District and 117,540 t year−1 in Attock District could be achieved by installing loose stone structures in 60 % of the agricultural areas of both districts having a slope of 0–4 %; these findings can serve as a reference for policymakers and planners. The overarching findings of this study show that the SWAT model provides reliable results for sediment yield and soil erosion estimation, which can be used in rocky mountainous watersheds for erosion control and watershed management.

scholarly journals Micro-Watershed Management for Erosion Control Using Soil and Water Conservation Structures and SWAT Modeling

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1439 ◽  
Author(s):  
Ghulam Nabi ◽  
Fiaz Hussain ◽  
Ray-Shyan Wu ◽  
Vinay Nangia ◽  
Riffat Bibi
Keyword(s):  
Watershed Management ◽  
Sediment Yield ◽  
Water Conservation ◽  
Soil Conservation ◽  
Swat Model ◽  
Erosion Control ◽  
Yield Reduction ◽  
Fallow Land ◽  
Soil And Water ◽  
Stone Structures

This study evaluated the effectiveness of soil and water conservation structures for soil erosion control by applying a semi-distributed Soil and Water Assessment Tool (SWAT) model in various small watersheds of the Chakwal and Attock districts of Pothwar, Pakistan. The validated model without soil conservation structures was applied to various ungauged small watershed sites with soil conservation stone structures. The stone bund-type structure intervention was used in the model through the modification of the Universal Soil Loss Equation (USLE) to support the practice factor (P-factor), the curve number, and the average slope length for the sub-basin (SLSUBBSN). The structures had significant effects, and the average sediment yield reduction caused by the soil conservation stone structures at these sites varied from 40% to 90%. The sediment yield and erosion reductions were also compared under conditions involving vegetation cover change. Agricultural land with winter wheat crops had a higher sediment yield than fallow land with crop residue. The fallow land facilitated sediment yield reduction, along with soil conservation structures. The slope classification analysis indicated that 60% of the agricultural area of the Chakwal and Attock districts lie in a slope range of 0–4%, where considerable potential exists for implementing soil conservation measures by installing soil conservation stone structures. The slope analysis measured the suitability of conservation structures in the semi-mountainous Pothwar area in accordance with agriculture practice on land having a slope of less than 5%. The SWAT model provides reliable performance for erosion control and watershed management in soil erosion-prone areas with steep slopes and heavy rainfall. These findings can serve as references for policymakers and planners.

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 Watershed Drought and Ecosystem Services: Spatiotemporal Characteristics and Gray Relational Analysis

2021 ◽  
Vol 10 (2) ◽  
pp. 43
Author(s):  
Jizhou Bai ◽  
Zixiang Zhou ◽  
Yufeng Zou ◽  
Bakhtiyor Pulatov ◽  
Kadambot H. M. Siddique
Keyword(s):  
Ecosystem Services ◽  
Soil Erosion ◽  
Vegetation Cover ◽  
Soil Conservation ◽  
Swat Model ◽  
Vegetation Restoration ◽  
Gray Relational Analysis ◽  
Relational Analysis ◽  
Spatiotemporal Characteristics ◽  
The Impact

This study explored the spatiotemporal characteristics of drought and ecosystem services (using soil conservation services as an example) in the YanHe Watershed, which is a typical water basin in the Loess Plateau of China, experiencing soil erosion. Herein, soil conservation was simulated using the Soil and Water Assessment Tool (SWAT), and the relationship between drought, soil conservation services, and meteorological, vegetation, and other factors since the implementation of the ‘Grain for Green’ Project (GFGP) in 1999, were analyzed using the gray relational analysis (GRA) method. The results showed that: (1) The vegetation cover of the Watershed has increased significantly, and evapotranspiration (ET) increased by 14.35 mm·a−1, thereby increasing water consumption by 8.997 × 108 m3·a−1 (compared to 2000). (2) Drought affected 63.86% of the watershed area, gradually worsening from south to north; it decreased in certain middle areas but increased in the humid areas on the southern edge. (3) The watershed soil conservation services, measured by the soil conservation modulus (SCM), increased steadily from 116.87 t·ha−1·a−1 in 2000 to 412.58 t·ha−1·a−1 in 2015, at a multi-year average of 235.69 t·ha−1·a−1, and indicated great spatial variations, with a large variation in the downstream and small variations in the upstream and midstream areas. (4) Integrating normalized difference vegetation index (NDVI) data into SWAT model improved the model simulation accuracy; during the calibration period, the coefficient of determination (R2) increased from 0.63 to 0.76 and Nash–Sutcliffe efficiency (NSE) from 0.46 to 0.51; and during the validation period, the R2 increased from 0.82 to 0.93 and the NSE from 0.57 to 0.61. (5) The GRA can be applied to gray control systems, such as the ecosystem; herein, vegetation cover and drought primarily affected ET and soil conservation services. The analysis results showed that vegetation restoration enhanced the soil conservation services, but increased ET and aggravated drought to a certain extent. This study analyzed the spatiotemporal variations in vegetation coverage and the response of ET to vegetation restoration in the YanHe Watershed, to verify the significant role of vegetation restoration in restraining soil erosion and evaluate the extent of water resource consumption due to ET in the semi-arid and semi-humid Loess-area basin during the GFGP period. Thus, this approach may effectively provide a scientific basis for evaluating the ecological effects of the GFGP and formulating policies to identify the impact of human ecological restoration on ecosystem services.

Impacts of climate and land use changes on the erosion processes in a Mediterranean agricultural catchment (Northern Morocco)

2021 ◽  
Author(s):  
Hamza Briak ◽  
Rachid Moussadek ◽  
Khadija Aboumaria ◽  
Fassil Kebede ◽  
Rachid Mrabet
Keyword(s):  
Land Use ◽  
Soil Erosion ◽  
Best Management Practices ◽  
Sediment Yield ◽  
Soil Conservation ◽  
Management Practices ◽  
Agricultural Land ◽  
Swat Model ◽  
Baseline Scenario ◽  
Erosion Processes

<p>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.</p>

scholarly journals The relative contributions of slope gradient and vegetation cover on erosion characteristics of riparian slopes along the lower Yellow River, China

2021 ◽  
Author(s):  
Zihao Cao ◽  
Qinghe Zhao ◽  
Shengyan Ding ◽  
Yifan Zhang
Keyword(s):  
Particle Size ◽  
Soil Erosion ◽  
Sediment Yield ◽  
Vegetation Cover ◽  
Yellow River ◽  
Size Composition ◽  
Steep Slope ◽  
Slope Gradient ◽  
Lower Yellow River ◽  
The Lower Yellow River

Slope gradient and vegetation cover play key roles in soil erosion process. Exploring the effects of slope gradient and vegetation cover on runoff and sediment yielding characteristics is therefore of great importance for minimizing soil erosion. In this work, based on field scouring experiments on the riparian slopes of the lower Yellow River, China, variation in total runoff, accumulative runoff sediment concentration, erosion sediment yield, and sediment particle size composition under four slope gradients (5°, 10°, 15°, 20°) and three vegetation cover levels (0%, 15%, 30%) were analyzed. Runoff and sediment yield were greatly influenced by slope gradient at steep slope gradients (15° and 20°), while they were mainly affected by vegetation cover at medium slope gradients (5° and 10°). The main enriched particle size of the eroded sediment showed a trend of first increasing and then decreasing with the increasing slope gradient. There was an interaction between slope gradient and vegetation cover, the effect of vegetation cover on erosion sediment yield weakened gradually with increasing slope gradient (at medium slope gradients of 5° and 10°), while the effect of slope gradient increased at steep slope gradients (15° and 20°).

scholarly journals Effects of water and soil conservation works on runoff and sediment variation in the areas with high and coarse sediment yield of the middle Yellow River

2018 ◽  
Vol 38 ◽  
pp. 01033
Author(s):  
Wei Ying Sun ◽  
Pan Zhang ◽  
Li Li ◽  
Jiang Nan Chen
Keyword(s):  
Sediment Yield ◽  
Water Conservation ◽  
Human Activities ◽  
Soil Conservation ◽  
Yellow River ◽  
Soil And Water Conservation ◽  
Contribution Rate ◽  
Rainfall Variation ◽  
Runoff Reduction ◽  
Soil And Water

The areas with high and coarse sediment yield of the middle Yellow River is well known for its severe erosion, high sediment yields. Since 1982 when the 8 key soil and water conservation harnessing regions has been built, the ecological environment has been gradually improved and the amount of sediment and runoff entering the Yellow River has been reduced continuously. Some researchers considered that it was owing to the water and soil conservation works (WSCW), while others believed that it was caused by the rainfall variation, but this has not been quantified for the effect respectively. This paper deals with the effects of WSCW on runoff and sediment variation. The study has been carried out in the Sanchuanhe River watershed, where was listed as one of the 8 key soil and water conservation harnessing regions. The results show that the contribution rate of human activities was 80.2% after 1st harnessing stage (1970-1979), 43.0% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 98.4%, and was 44.8% after 4th harnessing stage (1997-2006). With regard to the influence on runoff reduction in the watershed, the contribution rate of human activities was 62.5% compared with the natural factors after 1st harnessing stage (1970-1979), 28.4% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 69.6%, and was 37.0% after 4th harnessing stage (1997-2006). The results revealed that human activities exerted the largest effects on the sediment reduction and explained 66.6% of the variation in the specific sediment yield. This study suggests that a combination of human activities and rainfall variation effectively reduces runoff and sediment delivery of the Loess Plateau. Generally The runoff reduction and contribution of rainfall variation to runoff reduction in this area were as large as human activities. After many years' harnessing the great benefit have been obtained in water and soil loss control in this watershed.

The effects of multiple factors on spring meltwater erosion on an alpine meadow slope

2021 ◽  
Author(s):  
Xiaonan Shi ◽  
Fan Zhang ◽  
Li Wang
Keyword(s):  
Soil Erosion ◽  
Sediment Yield ◽  
Alpine Meadow ◽  
Alluvial Soil ◽  
Strong Impact ◽  
The Tibetan Plateau ◽  
Slope Gradient ◽  
Multiple Factors ◽  
Total Runoff ◽  
The Impact

<p>Serious soil erosion is observed during the spring because soil thawing coincides with the period of snowmelt and low meadow coverage at this time. Studies relating to soil erosion caused by spring meltwater are limited and controversial. In this study, a field experimental study was conducted in an alpine meadow slope in the Binggou watershed on the northern edge of the Tibetan Plateau to assess the impact of multiple factors on spring meltwater erosion. The multiple factors included three flow rates, four slope gradients, and three underlying surface conditions (meadow, disturbed meadow, and alluvial soil). An equal volume of concentrated meltwater flow was used in all experiments. The results showed that rapid melting at a high flow rate could accelerate soil erosion. The influence of the slope gradient on the amount of runoff was positively linear and the influence was relatively low. However, the slope gradient had a strong impact on soil erosion. The meadow could effectively reduce soil erosion, although when the meadow was disturbed, the total runoff increased by 60% and the sediment yield by a factor of 1.5. The total runoff from the alluvial soil doubled in comparison to the meadow, while the sediment yield increased nearly 7-fold. The findings of this study could be helpful to understand the characteristics and impact of multiple controlling factors of spring meltwater erosion. It also aims to provide a scientific basis for an improved management of alpine meadows as well as water and soil conservation activities in high-altitude cold regions.</p><p> </p>

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

scholarly journals Model of Soil and Water Conservation Measures Application based on District Spatial Planning in Mamasa Watershed, South Sulawesi

2017 ◽  
Vol 4 (2) ◽  
pp. 263
Author(s):  
Sri Malahayati Yusuf
Keyword(s):  
Watershed Management ◽  
Sediment Yield ◽  
Water Conservation ◽  
Surface Runoff ◽  
Alley Cropping ◽  
Swat Model ◽  
Remote Sensing Data ◽  
Runoff Coefficient ◽  
Climate Data ◽  
Scenarios Simulation

Depletion of watershed carrying capacity cannot be omitted from mismanagement of the watershed. The integration between SWAT model and remote sensing data are able to identify, assess, and evaluate watershed problem as well as a tool to apply the mitigation of the problem. The aim of this study was to arrange the scenario of watershed management, and decide the best recommendation of sustainable watershed management of Mamasa Sub Watershed. The best recommendation was decided by hydrology parameters, e.i. surface runoff, sediment, and runoff coefficient. Hydrology characteristics of Mamasa Sub Watershed was analyzed based on land use data of year 2012 and climate data for period of 2010-2012. The scenarios were  application of bunch and mulch in slope 1-15%; bunch terrace (scenario 1), mulch and strip grass in slope 15-25% (scenario 2), alley cropping in slope 25-40% (scenario 3), and combination scenario 1, 2, 3 with agroforestry in slope > 40% (scenario4). Surface runoff value of Mamasa Sub Watershed is 581.35 mm, while lateral flow, groundwater flow, runoff coefficient, and sediment yield of 640.72 mm, 228.17 mm, 0.29, and 187.213 ton/ha respectively. Based on the scenarios simulation, the fourth scenario was able to reduce surface runoff and sediment yield of 33.441% and of 51.213%, while the runoff coefficient declined to 0.194. Thereby, the fourth scenario is recommended to be applied in Mamasa Sub Watershed so that the sustainability in the watershed can be achieved.

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