Erosion hazard level analysis in the Lempong River Sub-Watershed Jenawi District in 2024

Abstract One of the geomorphological processes that causes changes in the shape of the earth’s surface is erosion. The impact of erosion causes thinning of the top layer of soil which results in the soil being degraded so that the infiltration capacity of the soil decreases drastically. High heat waves due to the climate crisis result in a lot of environmental damage. The slopes of Mount Lawu experienced quite severe land damage. This change in land use results in a decrease in the amount of vegetation, thereby triggering erosion. A river basin (DAS) is a water catchment area that is bounded by ridges or mountain ridges that rise from upstream to downstream of a river. Karanganyar Regency’s rainfall has decreased drastically due to the climate crisis. The climate crisis which is the high heat waves cause a lot of environmental damage. This study aims to analyze the level of erosion hazard that occurs in the Lempong River Sub-watershed, Jenawi District, Karang Anyar Regency. The study location is in Karanganyar Regency, precisely in the Lempong River sub-watershed, Jenawi District. This study uses secondary data taken from the web and various related literature such as rainfall data, slope map, soil type map, and land use map. This study uses the USLE method with qualitative descriptive analysis. The USLE method is a common method for calculating predictions of erosion hazard levels. We used this method because the advantage, which is the USLE method related to GIS. GIS will simplify and speed up the calculation of erosion magnitude results. Spatial data processing was carried out using ArcGIS software by overlaying the data that had been collected. The erosion hazard category of the Lempong River sub-watershed, Jenar District, is dominated by the large category in the upstream river area. Areas in the very large category are caused by land use in the form of residential areas. People need to understand the dangers of erosion so that they can prevent major impacts.