ANALISIS DAERAH RAWAN BANJIR DI DAS KEMUNING KABUPATEN SAMPANG MENGGUNAKAN PROGRAM ARCGIS

Abstract

Daerah Aliran Sungai (DAS) Kemuning di Kabupaten Sampang telah mengalami penurunan fungsi akibat sedimentasi dan perubahan penggunaan lahan, yang sering menyebabkan banjir dan mengganggu aktivitas masyarakat. Penelitian ini bertujuan untuk menganalisis curah hujan periode ulang 25 tahun, membuat peta tematik kerentanan banjir, menganalisis luas daerah rawan banjir, serta mengidentifikasi wilayah yang tergolong rawan banjir di DAS Kemuning. Metode penelitian menggunakan pendekatan Sistem Informasi Geografis (SIG) dengan metode kuantitatif deskriptif. Data yang digunakan meliputi curah hujan, jenis tanah, penggunaan lahan, data DEM untuk analisis kemiringan lereng, ketinggian lahan, dan peta buffer sungai. Data dianalisis menggunakan metode skoring dan overlay. Hasil penelitian menunjukkan bahwa curah hujan periode ulang 25 tahun di DAS Kemuning sebesar 78,42 mm. Peta tematik kerentanan banjir diklasifikasikan ke dalam lima kategori: tidak rentan, kurang rentan, cukup rentan, rentan, dan sangat rentan, yang masing-masing diwakili oleh warna berbeda. Wilayah rawan banjir terbesar masuk dalam kategori cukup rentan, seluas 251,99 km². Wilayah dengan kategori terbesar masing-masing terdapat di Desa Banyukapah (tidak rentan dan kurang rentan), Desa Gunungkesan (cukup rentan), Desa Muktesareh (rentan), dan Desa Panggung (sangat rentan). Penelitian ini diharapkan dapat menjadi acuan dalam upaya mitigasi banjir dan pengelolaan DAS yang berkelanjutan di masa depan.

Kata kunci: ArcGIS, Banjir, DAS Kemuning, Kabupaten Sampang

The Kemuning Watershed in Sampang Regency has experienced a decline in function due to sedimentation and land use changes, frequently causing floods that disrupt community activities. This study aims to analyze the 25-year return period rainfall, create thematic flood vulnerability maps, analyze the extent of flood-prone areas, and identify areas classified as flood-prone in the Kemuning Watershed. The research method uses a Geographic Information System (GIS) approach with a descriptive quantitative method. The data used include rainfall, soil types, land use, DEM data for slope analysis, land elevation, and river buffer maps. Data were analyzed using scoring and overlay methods. The results show that the 25-year return period rainfall in the Kemuning Watershed is 78.42 mm. The thematic flood vulnerability map is classified into five categories: not vulnerable, less vulnerable, moderately vulnerable, vulnerable, and highly vulnerable, each represented by different colors. The largest flood-prone area falls into the moderately vulnerable category, covering 251.99 km². The largest areas for each category are found in Banyukapah Village (not vulnerable and less vulnerable), Gunungkesan Village (moderately vulnerable), Muktesareh Village (vulnerable), and Panggung Village (highly vulnerable). This research is expected to serve as a reference for flood mitigation efforts and sustainable watershed management in the future.

Keywords: ArcGIS, Flood, Kemuning Watershed, Sampang Regency