Mojokerto Regency is one of the regencies in East Java with a high population growth rate of around 0.96%, thus encouraging significant land use changes on built-up areas. Classifying remote sensing imageries to obtain reliable and accurate land use and land cover (LULC) information remains a challenge that depends on many factors such as complexity of the landscape, the remote sensing data selected, image processing, and classification methods. This study examined the accuracy assessment of LULC classification using Google Earth in Sadar Watershed, Mojokerto, East Java Indonesia for the years 2010, 2015, and 2020. The land use was classified into five categories; those are agriculture land (paddy field, field, and plantation), non-agriculture land (forest land, bushland, grazing land), bare land, settlement land, and water bodies. Around 85 random points were generated in ArcGIS and verified with Google Earth. The results showed that the Overall Accuracy of LULCC for 2010 was 80.2% and Kappa Coefficient was 0.74; for 2015, the Overall Accuracy was 85.3% and Kappa Coefficient was 0.8, and for 2020, the Overall Accuracy was 84.0%, and Kappa Coefficient was 0.79. All accuracy is considered as good categorized and acceptable in both overall accuracy and Kappa Coefficient.

Erosion and sedimentation problems caused by human activities disturbed the primary conditions of the watershed. This situation was also influenced by significant hydrometeorological shifts and high rainfall, which increased soil erosion. These inclement watershed conditions resulted in high sedimentation rates and caused severe problems for the quality and quantity of water in the reservoir. This study aims to solve the Sermo watershed problems by calculating the value of erosion and sedimentation, then providing a solution to deal with these problems in the form of Best Management Practices (BMP). This research used a USLE method to calculate the erosion and sedimentation rate. The calculation results showed that 40.86% of Sermo Reservoir within 809.12 hectares was classified as a high level of erosion. Further recommendations for overcoming this condition were made by referring to BMP for erosion and sediment control, including structures and soil water conservation. Further recommendations to address this condition were made regarding BMP for controlling water, maintaining soil stability, controlling sedimentation, and managing and maintaining optimal watersheds.