Journal de télédétection et SIG

Abstrait

Spatial Morphometric Characterization of Akaki Watershed

Tesfamariam E. Mengesha

Several worldwide DEMs based on satellite data have been released in the last decade. The accuracy of these datasets is frequently uncertain, as it varies from dataset to dataset. The quality of a Digital Elevation Models (DEM) is a key criterion for many applications, and it is influenced by local land cover, terrain slope, and several stages of DEM processing, from collection through resampling interpolation. The primary goal of this research is to assess the quality of the most recent freely available global Multi-Error-Removed Improved Terrain (MERIT) DEM digital elevation models in the Akaki watershed for morphological parameter assessment. The DEMs used in this investigation were created at an original spatial location. It was discovered that the coarse grained DEM has an impact on the portrayal of terrain attributes. When compared to a ground Global Positioning System (GPS) point, the total vertical accuracy exhibits RMSE errors of 13.4 m and 0.38 m Mean Absolute Percentage Error (MAPE) DEM, respectively. The watershed’s morphmetric parameters were examined using standard GIS technique including relief, linear and areal aspect computations. The Akaki watershed was classified as a fourth-order watershed, with the regulating components of stream orders being physiography, rainfall, local lithology, and structure. Lower-order streams are the most common in the watershed.