Modified global soil risk map using soil erosion and saturated hydraulic conductivity maps

Soil erosion (SE) and saturated hydraulic conductivity (Ksat) are the essential indicators for land degradation and soil nutrient loss. Both processes are linked with each other as one can enhance the other resulting in positive feedback loops. The increase in soil erosion might block the macropores and reduce Ksat. In contrast, the reduction in Ksat triggers the runoff and increases soil erosion. However, modelling and predicting soil erosion, hydraulic properties are usually not adequately considered. We tried to link soil erosion directly with Ksat on a global scale. For this, we used global soil erosion and saturated hydraulic conductivity maps to yield combined soil risk classes. SE and Ksat maps were obtained from Borrelli et al. (2017) and Gupta et al. (2021), respectively. Each map was classified into six classes based on the previous studies. Moreover, both maps' classes were combined by creating six merged classes to develop the modified soil risk map. The modified soil risk map highlights regions with low Ksat and high SE. Furthermore, the final map was validated using continental and/or national sediment yield (SY) datasets. SY classes were compared with final risk classes to validate the accuracy of the map. The modified soil risk map showed higher accuracy compared to the SE map when compared with SY classes. This study demonstrates the first attempt to link soil erosion to soil hydraulic properties on large scales.