Land-Cover Change and Its Influence on Flood Risk in Nagari Pelangai, Koto VIII Pelangai, and Pasia Pelangai

Abstract

This study analyzes land cover changes and their correlation with flood risk in Nagari Pelangai, Koto VIII Pelangai, and Pasia Pelangai, located in Ranah Pesisir Subdistrict, Pesisir Selatan Regency, West Sumatra Province. Landsat and Sentinel satellite imagery from 2013, 2020, and 2024 were used to classify land cover using the Maximum Likelihood method. Results indicate a significant increase in paddy fields by 432.22 hectares, and a reduction in water bodies from 266.47 hectares to 47.69 hectares. The classification achieved an accuracy level of 81%. Spatial overlay analysis between land cover change and flood inundation maps reveals that the conversion of vegetation and water bodies into paddy fields and settlements occurred predominantly in lowland areas prone to flooding. Field data support these findings, with 10 out of 11 respondents reporting flood events with water depths ranging from 30 to 100 cm, lasting on average 24 hours. Key driving factors include population growth, agricultural intensification, sedimentation of water bodies, and weak spatial planning enforcement. The study demonstrates that land use dynamics directly contribute to increased flood risk and highlights the importance of spatial monitoring in sustainable land management.