Uncertainty analysis of soil erosion modelling using different resolution of open-source DEMs

Abstract

The Digital Elevation Model (DEM) is one of the important parameters of soil erosion assessment and notable uncertainties are found in using different resolutions of the DEM. Revised Universal Soil Loss Equation model has been applied to analyze the effect of open-source DEMs with different resolution and accuracy on the uncertainties of soil erosion modelling in a part of the Narmada river basin in Madhya Pradesh in central India. Selected open-source DEMs are GTOPO30 (1 km), SRTM (30 and 90 m), CARTOSAT (30 m) and ASTER (30 m), used for estimating erosion rate. Results with better accuracy are achieved with the high-resolution DEMs (30 m) with higher vertical accuracy than the coarse resolution DEMs with lower accuracy. This study has presented potential uncertainties introduced by the open-source DEMs in soil erosion modelling for better understanding of appropriate selection and acceptable errors for researchers.

Keywords:

• DEM
• RUSLE
• accuracy
• uncertainty
• soil erosion

Acknowledgements

The authors are thankful to the National Remote Sensing Centre (NRSC) for the satellite data and CARTOSAT DEM, Indian Meteorological Department (IMD) for the rainfall data, National Bureau of Soil Science (NBSS) for soil data and to the Central Water Commission (CWC) for observed sediment load data. The authors also show gratitude to the Council of Scientific & Industrial Research (CSIR) for financial assistance in the research. Authors are thankful to the Trade and Industry of Japan (METI) and the National Aeronautics and Space Administration (NASA) for the ASTER DEM and to the Pacific Climate Impacts Consortium (PCIC) for providing the GCM and NCEP data. The authors are also thankful to United States Geological Survey (USGS) for providing SRTM and GTOPO30 DEMs.