A Methodological Framework for Identification of Baseline Scenario and Assessing the Impact of DEM Scenarios on SWAT Mod
- PDF / 2,165,250 Bytes
- 20 Pages / 439.37 x 666.142 pts Page_size
- 3 Downloads / 148 Views
A Methodological Framework for Identification of Baseline Scenario and Assessing the Impact of DEM Scenarios on SWAT Model Outputs Harikrishna Sukumaran 1 & Sanat Nalini Sahoo 1 Received: 20 May 2020 / Accepted: 7 October 2020/ # Springer Nature B.V. 2020
Abstract
The study attempts to evaluate the impact of DEM source (AW3D30 DEM, CartoDEM v2 R1, SRTM v4.1 DEM and ASTER GDEM v2), DEM resolution (30 m to 1000 m), resampling approaches (nearest neighbor, bilinear interpolation, cubic convolution, majority) and area threshold (1500 Ha, 10,000 Ha, 25,000 Ha, 35,000 Ha, 50,000 Ha) on hydrological model (SWAT) simulated outputs. A methodological framework by two criteria: (1) DEM quality assessment and (2) river network delineation capability of DEM were developed for identifying best DEM among the considered DEMs for baseline scenario. It is found from the study that AW3D30 DEM best represented the terrain of the catchment among the evaluated topographic models with a least RMSE value of 7.44 m. Further AW3D30 DEM had the best river network extraction capability with a minimum RMSE value of 44.52 m in comparison with reference network. All the DEM scenarios were found to be insensitive for surface runoff. Ground water flow, evapotranspiration, potential evapotranspiration and water yield estimates did not show any sensitivity to DEM scenarios but soil water content showed its sensitivity to area threshold scenario. In water quality estimates, all DEM scenarios were found to be highly sensitive to sediment yields in comparison to total nitrogen and total phosphorus. Keywords Digital Elevation Models . Uncertainty analysis . Soil and Water Assessment Tool . Resampling technique . Upper Narmada catchment . AW3D30 DEM
1 Introduction Digital elevation models (DEMs), considered as the most important spatial input parameters for hydrological models, have an inherent source of uncertainties which could be due Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11269-02002691-5) contains supplementary material, which is available to authorized users.
* Sanat Nalini Sahoo [email protected]; [email protected]
1
Department of Civil Engineering, NIT Rourkela, Odisha, India
H. Sukumaran, S. N. Sahoo
to grid size or data sources. DEM uncertainty (in terms of its resolution, source, resampling technique and area threshold), forms an input uncertainty and can potentially impact the results of the popularly used semi-distributed hydrological model, Soil and Water Assessment Tool (SWAT), which predominantly relies on DEMs to derive the hydrological variables. The current study attempts in addressing a pertinent science question from the “twenty-three unsolved problems in hydrology” (Bloschl et al. 2019), i.e. how can we disentangle and reduce model/structural/input uncertainty in hydrologic prediction? The work focuses on one part of the question i.e., input uncertainty. The overarching research question is answered through a methodological framework for the identificatio
Data Loading...
