scholarly journals Modeling the Hydrological Characteristics of Hangar Watershed, Ethiopia

2020 ◽  
Author(s):  
Abdata Galata
Keyword(s):  
Goodness Of Fit ◽  
Assessment Tool ◽  
Swat Model ◽  
Integrated Water Resources Management ◽  
Water Balance Components ◽  
Warm Up ◽  
Hydrological Characteristics ◽  
Digital Elevation ◽  
Physically Based ◽  
Elevation Model

Modelling the hydrological characteristics of watershed is a method of understanding behavior and simulating the water balance components of watershed for planning and development of integrated water resources management. The soil and water assessment tool (SWAT) physically based hydrological modelling was used for modelling hydrologic characteristics of the Hangar watershed. The data used for this study were digital elevation model (DEM), land use land cover data, soil map, climatological and hydrological data. The model calibrated and validated using measured streamflow data of 13 years (1990-2002) and 9 years (2003-2011) respectively including warm-up period. The SWAT model performs well for both calibration (R2 = 0.87, NSE = 0.82 and PBIAS = +1.4) and validation (R2 = 0.89, NSE = 0.88 and PBIAS = +1.2). The sensitivity analysis, which was carried out using 18 SWAT parameters, identified the 13 most sensitive parameters controlling the output variable and with which goodness-of-fit was reached. The analysis results indicated that the watershed receives around, 9.6%, 59.9%, and 30.5% precipitation during dry, wet and short rainy seasons respectively. The received precipitation was lost by 9.6 %, 40.5%, and 41.3% in the form of evapotranspiration for each seasons correspondingly. The surface runoff contribution to the Watershed were 3.8%, and 79.2% during dry and wet seasons respectively, whereas, it contributes by 17.0% during short rainy seasons.

scholarly journals Sensitivity analysis of the DEM resolution and effective parameters of runoff yield in the SWAT model: a case study

2019 ◽  
Vol 69 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Mohammad Nazari-Sharabian ◽  
Masoud Taheriyoun ◽  
Moses Karakouzian
Keyword(s):  
Sensitivity Analysis ◽  
Assessment Tool ◽  
Swat Model ◽  
Computation Time ◽  
Effective Parameters ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Impact ◽  
Reduce Computation Time

Abstract This study investigates the impact of different digital elevation model (DEM) resolutions on the topological attributes and simulated runoff, as well as the sensitivity of runoff parameters in the Mahabad Dam watershed in Iran. The watershed and streamlines were delineated in ArcGIS, and the hydrologic analyses were performed using the Soil and Water Assessment Tool (SWAT). The sensitivity analysis on runoff parameters was performed, using the Sequential Uncertainties FItting Ver. 2 algorithm, in the SWAT Calibration and Uncertainty Procedures (SWAT-CUP) program. The results indicated that the sensitivity of runoff parameters, watershed surface area, and elevations changed under different DEM resolutions. As the distribution of slopes changed using different DEMs, surface parameters were most affected. Furthermore, higher amounts of runoff were generated when DEMs with finer resolutions were implemented. In comparison with the observed value of 8 m3/s at the watershed outlet, the 12.5 m DEM showed more realistic results (6.77 m3/s). Comparatively, the 12.5 m DEM generated 0.74% and 2.73% more runoff compared with the 30 and 90 m DEMs, respectively. The findings of this study indicate that in order to reduce computation time, researchers may use DEMs with coarser resolutions at the expense of minor decreases in accuracy.

scholarly journals DEM Resolution Impact on the Estimation of the Physical Characteristics of Watersheds by Using SWAT

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Waranyu Buakhao ◽  
Anongrit Kangrang
Keyword(s):  
Assessment Tool ◽  
Swat Model ◽  
Large Area ◽  
Mountain Area ◽  
Watershed Characteristics ◽  
Watershed Area ◽  
Dem Resolution ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Impact

A digital elevation model (DEM) is an important spatial input for automatic extraction of topographic parameters for the soil and water assessment tool (SWAT). The objective of this study was to investigate the impact of DEM resolution (from 5 to 90 m) on the delineation process of a SWAT model with two types of watershed characteristics (flat area and mountain area) and three sizes of watershed area (about 20,000, 200,000, and 1,500,000 hectares). The results showed that the total lengths of the streamline, main channel slope, watershed area, and area slope were significantly different when using the DEM datasets to delineate. Delineation using the SRTM DEM (90 m), ASTER DEM (30 m), and LDD DEM (5 m) for all watershed characteristics showed that the watershed sizes and shapes obtained were only slightly different, whereas the area slopes obtained were significantly different. The total lengths of the generated streams increased when the resolution of the DEM used was higher. The stream slopes obtained using the small area sizes were insignificant, whereas the slopes obtained using the large area sizes were significantly different. This suggests that water resource model users should use the ASTER DEM as opposed to a finer resolution DEM for model input to save time for the model calibration and validation.

scholarly journals Impact of Resolution and Source of Digital Elevation Model on Topological Attributes and Simulated Runoff by SWAT Model

2021 ◽  
Author(s):  
Farinaz Gholami ◽  
Alireza Nemati ◽  
Yue Li ◽  
Yang Hong ◽  
Junlong Zhang
Keyword(s):  
Digital Elevation Model ◽  
Assessment Tool ◽  
Swat Model ◽  
Computation Time ◽  
Low Resolution ◽  
Dem Resolution ◽  
Digital Elevation ◽  
Hydrologic Response Units ◽  
Elevation Model ◽  
The Impact

The Digital Elevation Model (DEM) of a watershed is one of the most important inputs in most hydrological analyses and plays a key role in the accurate prediction of various hydrological processes. Comprehensive knowledge of the impact of different DEM sources on the performance of a model is essential before utilizing the model. In this study, we evaluated the influence of TOPO1:25000, ASTER, and SRTM DEMs, as input, on the performance of the Soil and Water Assessment Tool (SWAT) model for the prediction of surface runoff. We also investigated the effect of the resolution of the studied DEM sources on the accuracy of the SWAT model in the estimation of runoff. The second objective of this study was to identify the most influential and the least impactful input parameters on the performance of the SWAT model. We studied the Zarrineh River watershed in Iran as a case study to compare the effect of the aforementioned DEM types and DEM resolution on the output of the SWAT model. The outcomes of the study demonstrated that influential parameters on predicted runoff as well as a few watershed parameters, such as reach lengths, reach slopes, number of sub-basins, and the number of hydrologic response units (HRU), differs noticeably when the DEM source and resolution changes. It was also observed that simulated results over-predict the runoff during low precipitation periods and under-predict the runoff during high precipitation months, and the accuracy of the simulated results decreases by reducing the DEM resolution. The results showed that the SWAT model had the best performance when the TOPO1:25000 DEM was used as the input source. Low-resolution DEMs are available to a wider range of researchers. The outcomes of the current study can be employed to estimate the impact of low-resolution input data on the simulated result as well as substantially reduce the computation time by decreasing the input DEMresolution with only a minor reduction of accuracy.

scholarly journals INFLUENCE OF SOIL TYPE IN STREAM FLOW AND RUNOFF MODELED FOR THE UPPER DIDESSA CATCHMENT SOUTHWEST ETHIOPIA USING SWAT MODEL

2019 ◽  
Vol 4 (4) ◽  
pp. 444-457 ◽  
Author(s):  
Adisu Befekadu Kebede
Keyword(s):  
Surface Runoff ◽  
Stream Flow ◽  
Assessment Tool ◽  
Swat Model ◽  
Model Performance ◽  
Hydrological Process ◽  
Southwest Ethiopia ◽  
Digital Elevation ◽  
Elevation Model ◽  
Water Assessment

This study aimed to model the flow of streams and identify the sub-basins responsible for the high flow in the Didessa watershed, southwest Ethiopia, considering the regional soils types. Soil and Water Assessment Tool (SWAT) model was used to simulate stream flow and quantify surface runoff. The input data used were Digital Elevation Model (DEM), land use/land cover map, soil map and metrological data. The data were obtained from Ministry of Water, Irrigation and Electricity and National Meteorology Agency of Ethiopia. Simulation of SWAT was used to identify the most vulnerable sub-basins to the hydrological process. The model was calibrated and validated using the stream flow data. The simulated stream flow was calibrated by the SWAT-CUP2012 calibration sub-model of SWAT-CUP SUFI2. Sensitivity analysis showed that curve numbers (CN2), ALPHA-BNK and CH-K2 are the most sensitive top three parameters. The R2 and Nash-Sutcliffe Efficiency (NSE) values were used to examine the model performance. The results indicate 0.84 and 0.80 for R2 and 0.65 and 0.54 for NSE during calibration and validation, respectively. The average annual surface runoff in the delineated catchment was 774.13 mm. Changes in precipitation explained 89% of the variation in surface runoff, as more than 89% of precipitation from the catchment converted to surface runoff. The most three annual surface runoffs contributing were the 11, 23 and 5 sub-basins. INFLUÊNCIA DO TIPO DE SOLO NO FLUXO DE CÓRREGOS PARA A BACIA SUPERIOR DO RIO DIDESSA, SUDOESTE DA ETIÓPIA UTILIZANDO O MODELO SWATResumoEste estudo teve como objetivo modelar o fluxo de córregos e identificar as sub-bacias responsáveis pelo alto fluxo na bacia hidrográfica do Rio Didessa, sudoeste da Etiópia, considerando os tipos de solos regionais. O modelo SWAT (Solo and Water Assessment Tool) foi utilizado para simular o fluxo da corrente e quantificar o escoamento superficial. Os dados de entrada utilizados foram o Modelo Digital de Elevação (DEM), mapa de uso / cobertura do solo, mapa do solo e dados metrológicos. Os dados foram obtidos no Ministério da Água, Irrigação e Eletricidade e Agência Nacional de Meteorologia da Etiópia. A simulação do SWAT foi utilizada para identificar as sub-bacias mais vulneráveis ao processo hidrológico. O modelo foi calibrado e validado usando os dados de fluxo dos córregos. O fluxo de corrente simulado foi calibrado pelo submodelo de calibração SWAT-CUP2012, do SWAT-CUP SUFI2. A análise de sensibilidade mostrou que os números da curva (CN2), ALPHA-BNK e CH-K2 são os três principais parâmetros mais sensíveis. Os valores de R2 e Nash-Sutcliffe Efficiency (NSE) foram usados para examinar o desempenho do modelo. Os resultados indicam 0,84 e 0,80 para R2 e 0,65 e 0,54 para NSE durante a calibração e validação, respectivamente. O escoamento superficial médio anual na bacia hidrográfica foi de 774,13 mm. Mudanças na precipitação explicaram 89% da variação no escoamento superficial, pois mais de 89% da precipitação da bacia foi convertida em escoamento superficial. As sub-bacias 11, 23 e 5 foram as que mais contribuíram para os fluxos superficiais anuais da Bacia do Rio Didessa. Palavras-chave: Tipo de solo. Análise sensitiva. Fluxo de córregos. Swat-Cup. Bacia Superior do Rio.

scholarly journals Integrated Impact of Digital Elevation Model and Land Cover Resolutions on Simulated Runoff by SWAT Model

2017 ◽  
Author(s):  
Mahmoud Saleh Al-Khafaji ◽  
Fouad Hussein Al-Sweiti
Keyword(s):  
Land Cover ◽  
Digital Elevation Model ◽  
Water Resource Management ◽  
Assessment Tool ◽  
Swat Model ◽  
Interactive Effects ◽  
Stream Network ◽  
Time Step ◽  
Digital Elevation ◽  
Elevation Model

Abstract. Complemental interactive effects of the Digital Elevation Model (DEM) and Land Cover (LC) resolutions on the estimated runoff by using Soil and Water Assessment Tool (SWAT), which is of critical importance for water resource management, was investigated in this paper. Also, to specify the optimal DEM and LC resolutions for maximizing accuracy of the estimated runoff for Dokan, Adhaim, and Duhok watersheds located in Iraq. Twenty daily time step based SWAT models of each watershed were implemented using five DEMs in conjunction with five LCs. Assessment of models results shows that the watershed delineation significantly affected by DEM resolution, especially in flat regions. However, there is no clearly discernible trend of this effect on the determination of watershed boundary, stream network, number of sub-basins and total area. Furthermore, the number of Hydrologic Response Units (HRUs) and the maximum altitudes are directly related to the DEM whereas the minimum altitudes have an inverse relationship with the DEM. Also, the number of HRUs increases with the increase in LC resolution until it reaches a maximum value and then starts to gradually decrease. While there is no significant trend between the accuracy of the estimated runoff and the increase in the DEM and LC resolutions. The most accurate estimated runoffs of Dokan, Adhaim and Duhok Watersheds were obtained by using DEM 90 m and LC 1000 m, DEM 250 m and LC 1000 m, and DEM 30 m and LC 30 m with Nash and Sutcliffe Efficiency of 0.59, 0.68 and 0.69 respectively.

scholarly journals Multi-site calibration and validation of SWAT with satellite-based evapotranspiration in a data-sparse catchment in southwestern Nigeria

2019 ◽  
Vol 23 (2) ◽  
pp. 1113-1144 ◽  
Author(s):  
Abolanle E. Odusanya ◽  
Bano Mehdi ◽  
Christoph Schürz ◽  
Adebayo O. Oke ◽  
Olufiropo S. Awokola ◽  
...  
Keyword(s):  
Soil Moisture ◽  
River Basin ◽  
Model Calibration ◽  
Hydrological Model ◽  
Assessment Tool ◽  
Potential Evapotranspiration ◽  
Swat Model ◽  
Water Balance Components ◽  
Southwestern Nigeria ◽  
Calibration And Validation

Abstract. The main objective of this study was to calibrate and validate the eco-hydrological model Soil and Water Assessment Tool (SWAT) with satellite-based actual evapotranspiration (AET) data from the Global Land Evaporation Amsterdam Model (GLEAM_v3.0a) and from the Moderate Resolution Imaging Spectroradiometer Global Evaporation (MOD16) for the Ogun River Basin (20 292 km2) located in southwestern Nigeria. Three potential evapotranspiration (PET) equations (Hargreaves, Priestley–Taylor and Penman–Monteith) were used for the SWAT simulation of AET. The reference simulations were the three AET variables simulated with SWAT before model calibration took place. The sequential uncertainty fitting technique (SUFI-2) was used for the SWAT model sensitivity analysis, calibration, validation and uncertainty analysis. The GLEAM_v3.0a and MOD16 products were subsequently used to calibrate the three SWAT-simulated AET variables, thereby obtaining six calibrations–validations at a monthly timescale. The model performance for the three SWAT model runs was evaluated for each of the 53 subbasins against the GLEAM_v3.0a and MOD16 products, which enabled the best model run with the highest-performing satellite-based AET product to be chosen. A verification of the simulated AET variable was carried out by (i) comparing the simulated AET of the calibrated model to GLEAM_v3.0b AET, which is a product that has different forcing data than the version of GLEAM used for the calibration, and (ii) assessing the long-term average annual and average monthly water balances at the outlet of the watershed. Overall, the SWAT model, composed of the Hargreaves PET equation and calibrated using the GLEAM_v3.0a data (GS1), performed well for the simulation of AET and provided a good level of confidence for using the SWAT model as a decision support tool. The 95 % uncertainty of the SWAT-simulated variable bracketed most of the satellite-based AET data in each subbasin. A validation of the simulated soil moisture dynamics for GS1 was carried out using satellite-retrieved soil moisture data, which revealed good agreement. The SWAT model (GS1) also captured the seasonal variability of the water balance components at the outlet of the watershed. This study demonstrated the potential to use remotely sensed evapotranspiration data for hydrological model calibration and validation in a sparsely gauged large river basin with reasonable accuracy. The novelty of the study is the use of these freely available satellite-derived AET datasets to effectively calibrate and validate an eco-hydrological model for a data-scarce catchment.

scholarly journals A New Physically-Based Spatially-Distributed Groundwater Flow Module for SWAT+

Hydrology ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 75
Author(s):  
Ryan T. Bailey ◽  
Katrin Bieger ◽  
Jeffrey G. Arnold ◽  
David D. Bosch
Keyword(s):  
Water Balance ◽  
Groundwater Flow ◽  
Land Surface ◽  
Assessment Tool ◽  
Swat Model ◽  
Watershed Model ◽  
Groundwater Head ◽  
Physically Based ◽  
Spatially Distributed ◽  
Modeling Code

Watershed models are used worldwide to assist with water and nutrient management under conditions of changing climate, land use, and population. Of these models, the Soil and Water Assessment Tool (SWAT) and SWAT+ are the most widely used, although their performance in groundwater-driven watersheds can sometimes be poor due to a simplistic representation of groundwater processes. The purpose of this paper is to introduce a new physically-based spatially-distributed groundwater flow module called gwflow for the SWAT+ watershed model. The module is embedded in the SWAT+ modeling code and is intended to replace the current SWAT+ aquifer module. The model accounts for recharge from SWAT+ Hydrologic Response Units (HRUs), lateral flow within the aquifer, Evapotranspiration (ET) from shallow groundwater, groundwater pumping, groundwater–surface water interactions through the streambed, and saturation excess flow. Groundwater head and groundwater storage are solved throughout the watershed domain using a water balance equation for each grid cell. The modified SWAT+ modeling code is applied to the Little River Experimental Watershed (LREW) (327 km2) in southern Georgia, USA for demonstration purposes. Using the gwflow module for the LREW increased run-time by 20% compared to the original SWAT+ modeling code. Results from an uncalibrated model are compared against streamflow discharge and groundwater head time series. Although further calibration is required if the LREW model is to be used for scenario analysis, results highlight the capabilities of the new SWAT+ code to simulate both land surface and subsurface hydrological processes and represent the watershed-wide water balance. Using the modified SWAT+ model can provide physically realistic groundwater flow gradients, fluxes, and interactions with streams for modeling studies that assess water supply and conservation practices. This paper also serves as a tutorial on modeling groundwater flow for general watershed modelers.

scholarly journals The Shuttle Radar Topography Mission Digital Elevation Model as an alternative data source for deriving hydrological characteristics in lowland catchment — Rogożynek catchment case study

2009 ◽  
Vol 41 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Michał Wasilewski ◽  
Jarosław Chormański
Keyword(s):  
Digital Elevation Model ◽  
Shuttle Radar Topography Mission ◽  
Srtm Dem ◽  
Hydrological Characteristics ◽  
Wetspa Model ◽  
Digital Elevation ◽  
Data Source ◽  
Elevation Model ◽  
Topography Data

The Shuttle Radar Topography Mission Digital Elevation Model as an alternative data source for deriving hydrological characteristics in lowland catchment — Rogożynek catchment case study This paper describes possibility of supplementing digital topography data needed for hydrologic modeling (WetSpa model) of lowland catchment with existing, freely available DEM data obtained from Shuttle Radar Topography Mission launched on February 11th, 2000. Rogożynek basin (Upper Biebrza) as case study is given. Authors compared three DEMs: topographic — TOPO DEM 20 (20 m resolution), radar — SRTM DEM 90 (90 m res.) and resampled radar — SRTM DEM 20 (20 m res.). There were several characteristics compared and analyzed like: relative height differences, slopes, generated river network and generated subwatersheds (subbasins).

scholarly journals Performance of HEC-HMS and SWAT to simulate streamflow in the sub-humid tropical Hemavathi catchment

2021 ◽  
Author(s):  
N. C. Sanjay Shekar ◽  
D. C. Vinay
Keyword(s):  
Model Calibration ◽  
Assessment Tool ◽  
Swat Model ◽  
Model Performance ◽  
Curve Number ◽  
Coefficient Of Determination ◽  
Hydrological Models ◽  
Daily Streamflow ◽  
Compensation Factor ◽  
Elevation Model

Abstract The present study was conducted to examine the accuracy and applicability of the hydrological models Soil and Water Assessment Tool (SWAT) and Hydrologic Engineering Center (HEC)- Hydrologic Modeling System (HMS) to simulate streamflows. Models combined with the ArcGIS interface have been used for hydrological study in the humid tropical Hemavathi catchment (5,427 square kilometer). The critical focus of the streamflow analysis was to determine the efficiency of the models when the models were calibrated and optimized using observed flows in the simulation of streamflows. Daily weather gauge stations data were used as inputs for the models from 2014–2020 period. Other data inputs required to run the models included land use/land cover (LU/LC) classes resulting from remote sensing satellite imagery, soil map and digital elevation model (DEM). For evaluating the model performance and calibration, daily stream discharge from the catchment outlet data were used. For the SWAT model calibration, available water holding capacity by soil (SOL_AWC), curve number (CN) and soil evaporation compensation factor (ESCO) are identified as the sensitive parameters. Initial abstraction (Ia) and lag time (Tlag) are the significant parameters identified for the HEC-HMS model calibration. The models were subsequently adjusted by autocalibration for 2014–2017 to minimize the variations in simulated and observed streamflow values at the catchment outlet (Akkihebbal). The hydrological models were validated for the 2018–2020 period by using the calibrated models. For evaluating the simulating daily streamflows during calibration and validation phases, performances of the models were conducted by using the Nash-Sutcliffe model efficiency (NSE) and coefficient of determination (R2). The SWAT model yielded high R2 and NSE values of 0.85 and 0.82 for daily streamflow comparisons for the catchment outlet at the validation time, suggesting that the SWAT model showed relatively good results than the HEC-HMS model. Also, under modified LU/LC and ungauged streamflow conditions, the calibrated models can be later used to simulate streamflows for future predictions. Overall, the SWAT model seems to have done well in streamflow analysis capably for hydrological studies.

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