Erosion Rate in Post-Coal Mining Reclamation Area in Kutai Kartanegara District, Indonesia

Erosion is the transport of parts of the soil from one place to another by natural agent, namely water, and wind. Mining in Indonesia generally uses open-pit mining methods. Generally, open pit mining has a very high erosion rate due to damage to soil aggregation and high interaction with rainwater. This study aims to determine the erosion rate and hazard class in the post-coal mining reclamation area. The research location was in the Jembayan Muarabara Group, Kutai Kartanegara Regency, East Kalimantan Province, from February 2021 to May 2021. The erosion rate measurement in this study used the stick method by measuring the erosion rate based on the change in soil surface loss in centimetres (cm) units. Erosion rate data collection is carried out periodically every month. The results showed that the highest erosion was in the Disposal area, namely 558.55 - 1341.94 tons/ha/year, including class V (very high), in the Stock Soil area with an erosion rate of 471.79 - 693.51 tons/ha/year including class IV (high) to class V (very high) and the lowest erosion rate in the reclamation area in 2019, namely 189.51 - 673.88 tons/ha/year including class IV (high) to class V (very high). Factors that affect the magnitude of the erosion rate are land cover vegetation, soil slope, and the soil's physical properties.