Estimation of susceptibility to erosion-soil loss in drainage basins: a case study

Erosion-soil loss is responsible for long-term environmental impacts due to water resource silting process and biodiversity loss. Studies focusing in erosion-soil loss are important for understanding phenomena affecting the environment. Therefore, this study aimed to analyze and characterize the susceptibility to soil erosion in drainage basins in the municipality of Jataí, located in the southwest of the state of Goiás/Brazil (used as case study model). The places most susceptible to soil losses in the studied context are located in the northwest, southwest and southeast regions of Jataí. The rainfall erosivity (R) indices in the period from 2000 to 2020 were classified as medium (500–750 tn mm ha−1 year−1), high (750–1000 tn mm ha−1 year−1) and very high (> 1000 tn mm ha−1 year−1). With regard to soil erodibility (K), the most prone to erosion are the entisol with a K value of around 0.029 t/ha MJ−1 mm−1 and the entisol with 0.041 t/ha MJ−1 mm−1. As for the topographic factor (LS), values between 3.3 and 5.5, considered moderate, occupy 317.88 km2; the ranges between 5.5 and 7.5, representing 57.69 km2, are considered to have moderately strong susceptibility. Although 46.14% of the analyzed basins have mild-to-moderate susceptibility (FAO), in an area of just over 1316.46 km2 (18.35%), there are susceptibilities of severe to very severe, formed by the soils entisol, ultisol and oxisols, with slopes between 45 and 75%. This study demonstrated to be useful for proposing environmental monitoring policies of drainage basin areas affected by erosion. Graphic abstract