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 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 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 Spatial Modeling of Flood Sea Tides (Case Study: East Coast Semarang)

2004 ◽  
Vol 18 (1) ◽  
Author(s):  
Muhammad Aris Marfai
Keyword(s):  
Open Space ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Spatial Modelling ◽  
Flood Level ◽  
Digital Elevation ◽  
Elevation Model ◽  
Gis Software ◽  
The Impact

The aims of this research are 1) to construct a spatial model of tidal flood hazard, 2) to do hazard analysis of tidal flood. Spatial modelling has been generated using Geographic Information System (GIS) software and ILWIS software was seleccted to do the model operation. Neighborhood function and digital elevation model (DEM) have been applied on the modelling calculation process. DEM data was correted and menipulated using map calculation on the digital form. Tidal flood hazard analysis has been done by means of map calulation on the tidal flood hazard map and detail landuse map. Histogram and tabulation from the result of the map calculation have been analyzed to identify the impact of the tidal flood hazard on the landuse. The highest impact of the tidal flood hazard occurs on the 1 meter of tidal flood level, where in the inundation occurs mainly on the fishpond and yard/ open space area.

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 Effect of DEM Resolution on Runoff Yield, and Sensitivity of Parameters Contributing to Runoff in a Watershed

2019 ◽  
Author(s):  
Mohammad Nazari-Sharabian ◽  
Moses Karakouzian ◽  
Sajjad Ahmad
Keyword(s):  
Assessment Tool ◽  
Space Shuttle ◽  
Computation Time ◽  
Shuttle Radar Topography Mission ◽  
Alos Palsar ◽  
Dem Resolution ◽  
Digital Elevation ◽  
Speed Up ◽  
Sensitive Parameters ◽  
The Impact

Digital Elevation Models (DEMs) are essential in watershed delineation, but the sensitivity of simulated runoff to DEM resolution is poorly understood. This study investigates the impact of DEM resolution on topological attributes and simulated runoff in the Mahabad Dam watershed, Iran. To delineate the watershed, DEMs with 12.5 m, 30 m, and 90 m resolutions were acquired from the ALOS PALSAR, Space Shuttle Radar Topography Mission (SRTM), and ASTER global DEM data source, respectively. Watershed and streamlines were delineated in ArcGIS, with hydrologic analyses performed using the Soil and Water Assessment Tool (SWAT). Sensitivity analysis on parameters contributing to runoff was done using Sequential Uncertainties Fitting Ver-2 (SUFI-2) Algorithm, in SWAT Calibration and Uncertainty Procedures (SWAT-CUP) software. Results showed the watershed area, reach lengths, and elevations in the watershed varied due to DEM resolutions. Higher amounts of runoff were generated when DEMs with finer resolutions were implemented. The 12.5 m DEM generated 3.48% and 0.42% more runoff compared with 90 m and 30 m DEMs, respectively. SWAT-CUP results showed the sensitivity of parameters contributing to runoff changes under different DEM resolutions. Regardless of DEM resolution, surface properties, available water capacity, and moisture levels in the soil are the most sensitive parameters. As the distribution of slope changes in different DEM resolutions, surface parameters are most affected. The findings indicate to reduce computation time and speed up computation procedures, researchers may use DEMs with coarser resolutions at the expense of minor decreases in accuracy.

scholarly journals A Depression-Based Index to Represent Topographic Control in Urban Pluvial Flooding

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2115 ◽  
Author(s):  
Huabing Huang ◽  
Xi Chen ◽  
Xianwei Wang ◽  
Xina Wang ◽  
Lin Liu
Keyword(s):  
Limited Attention ◽  
Topographic Wetness Index ◽  
Digital Elevation ◽  
Pluvial Flooding ◽  
Elevation Model ◽  
The Stability ◽  
Urban Pluvial Flooding ◽  
The Impact ◽  
Flooded Areas

Extensive studies have highlighted the roles of rainfall, impervious surfaces, and drainage systems in urban pluvial flooding, whereas topographic control has received limited attention. This study proposes a depression-based index, the Topographic Control Index (TCI), to quantify the function of topography in urban pluvial flooding. The TCI of a depression is derived within its catchment, multiplying the catchment area with the slope, then dividing by the ponding volume of the depression. A case study is demonstrated in Guangzhou, China, using a 0.5 m-resolution Digital Elevation Model (DEM) acquired using Light Detection and Ranging (LiDAR) technology. The results show that the TCI map matches well with flooding records, while the Topographic Wetness Index (TWI) cannot map the frequently flooded areas. The impact of DEM resolution on topographic representation and the stability of TCI values are further investigated. The original 0.5 m-resolution DEM is set as a baseline, and is resampled at resolutions 1, 2, 5, and 10 m. A 1 m resolution has the smallest TCI deviation from those of 0.5 m resolution, and gives the optimal results in terms of striking a balance between computational efficiency and precision of representation. Moreover, the uncertainty in TCI values is likely to increase for small depressions.

scholarly journals Effect of GIS parameters on modelling runoff from river basin. The case study of catchment in the Puck District

2018 ◽  
Vol 63 ◽  
pp. 00005 ◽  
Author(s):  
Dominika Kalinowska ◽  
Paweł Wielgat ◽  
Tomasz Kolerski ◽  
Piotr Zima
Keyword(s):  
Model Resolution ◽  
Basic Assumptions ◽  
National Centre ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Impact ◽  
Digital Elevation Model Resolution ◽  
Puck Bay

The study was preceded to check the impact of the adopted digital elevation model resolution on the determination of catchment parameters and the further influence of the received information on calculations related to the hydrograph at the closing point of the basin after a synthetic 100-year precipitation episode. The study area are river basins located in the Puck commune convoying water directly to the Puck Bay. These studies allowed the formulation of the basic assumptions for the research project (in short called WaterPuck) supported by the National Centre for Research and Development.

scholarly journals ANÁLISE DE SENSIBILIDADE DE PARÂMETROS HIDROLÓGICOS NA BACIA DO RIO DAS PEDRAS - GUARAPUAVA-PR

2019 ◽  
Vol 12 (5) ◽  
pp. 1746
Author(s):  
Rafael Adriano de Castro Adriano de Castro ◽  
Elias Machado
Keyword(s):  
Sensitivity Analysis ◽  
Input Data ◽  
Assessment Tool ◽  
Swat Model ◽  
Coefficient Of Determination ◽  
Land Use And Management ◽  
The Impact ◽  
Water Assessment ◽  
Soil And Water

O modelo Soil and Water Assessment Tool (SWAT) é amplamente utilizado para predizer o impacto das alterações no uso e no manejo do solo, entre outros, é extremamente sensível à qualidade dos dados de entrada.  Assim, antes da simulação é necessário que se realize uma análise de sensibilidade de tal forma que se possa dar ênfase maior à aquisição e refinamento de determinados dados, diminuir as incertezas e aumentar a confiança nos resultados gerados. Os resultados simulados na bacia do Rio das Pedras – Guarapuava, foram realizadas a análise de sensibilidade e a calibração do modelo SWAT. Após a calibração do modelo os resultados do Índice de Nash & Sutcliffe alterado (COE), do percentual de tendência (PBIAS), e o coeficiente de determinação (R²) foram, respectivamente, 0,69, -0,5 e 0,7, indicando bom ajuste entre a vazão média mensal da bacia Rio das Pedras simulada pelo modelo SWAT em relação aos dados observados.  Sensitivity analysis of hydrological parameters in the Rio das Pedras basin - Guarapuava-PR A B S T R A C TThe SWAT model is widely used to predict the impact of changes in land use and management, among others, is extremely sensitive to the quality of input data. Thus, prior to the simulation, it is necessary to perform a sensitivity analysis in such a way that greater emphasis can be placed on the acquisition and refinement of certain data, decrease uncertainties and increase confidence in the results generated. The simulated results in the Rio das Pedras - Guarapuava basin, were performed the sensitivity analysis and calibration of the SWAT model. After the calibration of the model, the results of the modified Nash & Sutcliffe Index (COE), percentage of trend (PBIAS), and coefficient of determination (R²) were, respectively, 0.69, -0.5 and 0.7, Indicating a good fit between the average monthly flow of the Rio das Pedras basin simulated by the SWAT model in relation to the observed data. 

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.

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