scholarly journals HYDROLOGIC RESPONSE MODELLING IN LUTANANDWA RIVER CATCHMENT, LIMPOPO, SOUTH AFRICA, USING SOIL WATER ASSESSMENT TOOL (SWAT) MODEL

Author(s):  
J.P.O Obiero ◽  
M.O Marenya ◽  
T.R Nkuna ◽  
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2021 ◽  
Vol 5 (2) ◽  
pp. 173-182
Author(s):  
Shehu Usman Haruna ◽  
Aliyu Kasim Abba ◽  
Rabi'u Aminu

The present study compared the performance of two different models for streamflow simulation namely: Soil Water Assessment Tool (SWAT) and the Artificial Neural Network (ANN). During the calibration periods, the Nash-Sutcliff (NS) and Coefficient of Determination (R2) for SWAT was 0.74 and 0.81 respectively, whereas for ANN, it was 0.99 and 0.85 respectively. The ANN performs better during the validation period as the result revealed with NS and R2 having 0.98 and 0.89 respectively, while for the SWAT model it was 0.71 and 0.74 respectively. Based on the recommended comparison of graphical and statistical evaluation performances of both models, the ANN model performed better in estimating peak flow events than the SWAT model in the Upper Betwa Basin. Furthermore, the rigorous time required and expertise for calibration of the SWAT is much less as compared with the ANN. Moreover, the results obtained from both models demonstrate the performances of the


Author(s):  
Yongchao Duan ◽  
Fanhao Meng ◽  
Tie Liu ◽  
Yue Huang ◽  
Min Luo ◽  
...  

Floods not only provide a large amount of water resources, but they also cause serious disasters. Although there have been numerous hydrological studies on flood processes, most of these investigations were based on rainfall-type floods in plain areas. Few studies have examined high temporal resolution snowmelt floods in high-altitude mountainous areas. The Soil Water Assessment Tool (SWAT) model is a typical semi-distributed, hydrological model widely used in runoff and water quality simulations. The degree-day factor method used in SWAT utilizes only the average daily temperature as the criterion of snow melting and ignores the influence of accumulated temperature. Therefore, the influence of accumulated temperature on snowmelt was added by increasing the discriminating conditions of rain and snow, making that more suitable for the simulation of snowmelt processes in high-altitude mountainous areas. On the basis of the daily scale, the simulation of the flood process was modeled on an hourly scale. This research compared the results before and after the modification and revealed that the peak error decreased by 77% and the time error was reduced from ±11 h to ±1 h. This study provides an important reference for flood simulation and forecasting in mountainous areas.


2019 ◽  
Vol 11 (1) ◽  
pp. 49
Author(s):  
Samsul Labaco ◽  
Usman Arsyad ◽  
Anwar Umar

The disruption of hydrological cycle will reduce watershed's ability to store water, so that discharge in dry season decreases and discharge in rainy season increases. These problems are caused by changes in land cover from forested land to non-forested. This study aims to develop a scenario for land cover planning that should be applied in the Lisu Watershed, Barru Regency. This study is mapping based on non-experimental research. The data obtained were analyzed spatially by overlay method. The Soil Water Assessment Tool (SWAT) model is used in preparation of land cover planning scenarios to predict hydrological conditions. The results showed that scenario 2, namely land cover planning based on the district space map pattern is the best scenario. Addition of forest area to 61.60% resulting in the lowest yield of 3461.54 mm/year and 1519.53 mm/year. While the infiltration value produced is the highest infiltration value, which is 2299.20 mm/year.


2021 ◽  
Vol 3 ◽  
Author(s):  
Prakrut Kansara ◽  
Venkataraman Lakshmi

The Narmada River is one of the largest rivers in Western India encompassing a watershed area of 92,672 km2. It is one of the most important rivers for water needs of the state of Gujarat, Maharashtra, and Madhya Pradesh. The climate of the basin is humid and tropical but region surrounding this river watershed is predominantly dry and resembles semi-arid conditions. The population inside the states covering this watershed increased by an average of 23% from 1991 to 2011 causing multitude of water scarcity and water quality deterioration issues. These problems were caused by increase in sewage waste and untreated industrial discharge dumped into the river stream along with chemical fertilizers washing off from the farmlands flowing into the river. While there are several studies that model the watershed hydrology and water balance components, there has been no study that analyses the transport of nutrients inside the watershed. This study aims at using a semi-distributed hydrological model—Soil Water Assessment Tool (SWAT) to model the nitrogen (NO2 + NO3) transport and distribution inside the basin for 2001–2019. Nutrients and discharge data from Central Water Commission (CWC) of India were used to build this model along with other required input forcing obtained through remotely sensed datasets. We found that the subbasins near boundary of the Narmada watershed are experiencing significant increase in nitrogen concentrations at an estimated rate of 0.0001–0.002 mg/L/yr. The potential reason for such increase is high rate of conversion of forested land to agricultural land causing usage of fertilizers that are rich in nitrogen.


2014 ◽  
Vol 49 (4) ◽  
pp. 372-385
Author(s):  
Shawn Burdett ◽  
Michael Hulley ◽  
Andy Smith

A hydrologic and water quality model is sought to establish an approach to land management decisions for a Canadian Army training base. Training areas are subjected to high levels of persistent activity creating unique land cover and land-use disturbances. Deforestation, complex road networks, off-road manoeuvres, and vehicle stream crossings are among major anthropogenic activities observed to affect these landscapes. Expanding, preserving and improving the quality of these areas to host training activities for future generations is critical to maintain operational effectiveness. Inclusive to this objective is minimizing resultant environmental degradation, principally in the form of hydrologic fluctuations, excess erosion, and sedimentation of aquatic environments. Application of the Soil Water Assessment Tool (SWAT) was assessed for its ability to simulate hydrologic and water quality conditions observed in military landscapes at 5th Canadian Division Support Base (5 CDSB) Gagetown, New Brunswick. Despite some limitations, this model adequately simulated three partial years of daily watershed outflow (NSE = 0.47–0.79, R2 = 0.50–0.88) and adequately predicted suspended sediment yields during the observation periods (%d = 6–47%) for one highly disturbed sub-watershed in Gagetown. Further development of this model may help guide decisions to develop or decommission training areas, guide land management practices and prioritize select landscape mitigation efforts.


2008 ◽  
Vol 7 (5) ◽  
pp. 453-466 ◽  
Author(s):  
Étienne Lévesque ◽  
Luc Lamontagne ◽  
Ann Van Griensven ◽  
Peter A. Vanrolleghem ◽  
François Anctil

2020 ◽  
Author(s):  
Francis Kilundu Musyoka ◽  
Andreas Klik ◽  
Peter Strauss

<p>Hydrological models enable comprehensive examination, understanding and quantification of hydrological processes in catchments under the influence of different characteristics. The Soil and Water Assessment Tool (SWAT) has the ability to predict the impact of land management practices on water, sediment and agricultural chemical yield in such catchments.</p><p>The objective of this study is to apply the SWAT model on a small agricultural watershed, calibrate and validate it with measured flow, sediment and crop yield data. The model is set up for the HOAL catchment in Petzenkirchen, Lower Austria. The catchment has an area of 66 hectares. The climate is humid with mean annual temperatures of around 10°C, and annual precipitation of around 800 mm. Soils include Cambisols and Planosols with medium to poor infiltration capacities. Gleysols occur close to the stream. At present, 87% of the catchment area is arable land, 5% is used as pasture, 6% is forested and 2% is paved. The agricultural activities mainly involve wheat based crop rotation including winter wheat, winter barley, sweet and silage corn and canola. The catchment is divided into 37 fields and for each field exact information about tillage date and type of implement used, date of planting and harvest, date and amount of fertilization and plant protection are available. This information is incorporated in the model during set up. The procedures of model set up, sensitivity analysis, calibration and validation are outlined. A Sequential Uncertainty Fitting (SUFI-2) procedure within SWAT-CUP is used to auto-calibrate and validate the model. The model calibration (2012-2014) and validation (2015-2017) is based on the observed daily discharge and daily sediment concentration at the watershed outlet. Event based observations of runoff and sediment yield from two sub-watersheds are available as well as measured soil water contents at 30 points and crop yield data from different fields. Stream flow and sediment calibration are performed at the watershed outlet as well as at sub watershed level. Results of the SWAT model capability to predict flow, sediment and crop yield as well as soil water contents in the small watersheds will be presented.</p>


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