Mapping sediment mobilization risks: Prioritizing results obtained at watershed and sub-watershed scales

Abstract

Soils are key natural resources for the Earth’s system; however, human impacts, especially, soil erosion are considered serious threats. Therefore, identifying and assessing effective factors to understand erosion hot spots at different scales is critical to developing effective land management plans and ensuring the sustainability of the territory. This study was conducted to determine and prepare an erosion risk map, but to prioritize the survey at different scales, such as sub-basin and watershed ones. To achieve this goal, geographic information system (GIS) and remote sensing data (RS) were used combining the analysis network process method (ANP) and ICONA model (Institute for the Conservation of Nature). As study case, we selected the degraded areas of the Gorganrood watershed located in the north of Iran. The study area was obtained for very low, low, medium, high, and very high-risk classifications of 14.0, 21.4, 17.9, 31.3, and 15.4%, respectively. Results from the ICONA model also indicated that 12.8, 28.8, 22.1, 27.9, 8.5, and 0.03% belong to very low, low, medium, high, very high, and without risk of erosion, respectively. According to the validation results, it was found that the accuracy of ANP and ICONA models are 0.83 and 0.80, respectively, which indicates the suitability of the models for preparing the erosion map of the region is appropriate and useful for designing land management plans. We conclude that both models can be used to develop the erosion map potential and to prioritize sub-basins if a complete database of geomorphological characteriscs and human activities are accurate previously defined.