Chapter 3 - Comprehensive introduction to Digital Elevation Models, as a key dataset in soil erosion mapping

Abstract

The evaluation of DEMs is vital for assessing their accuracy, improving data quality, determining their suitability for specific applications, identifying data gaps and uncertainties, and enhancing decision-making processes. It allows users to make informed choices, understand limitations, and ensure the reliability of elevation data for various applications, including soil erosion modeling. This chapter provided a comprehensive review of DEM concepts, encompassing different definitions, data sources, and quality aspects. Additionally, a novel experiment was proposed to evaluate three global DEMs (ALOS, SRTM, and ASTER) in a wide area of Iran, specifically focusing on four sub-basins in the Fars province. Instead of relying on ground-based surveying methods like GPS, the generated GCP dataset utilized ICESat-2, which proved to be an effective tool for DEM evaluation due to its high precision elevation measurements, global coverage, and independent validation. The study findings revealed that the ALOS DEM provided the most accurate and detailed representation of the terrain, while GDEMs exhibited highly variable accuracy. The accuracy of GDEMs notably depended on the specific characteristics of the local terrain.