Zonasi Tingkat Kerawanan Banjir Pada Ruas Bekas Sungai di Kabupaten Sukoharjo

Abstract

AbstractKecamatan Tawangsari dan Kecamatan Sukoharjo, Kabupaten Sukoharjo, Provinsi Jawa Tengah merupakan wilayah yang dilalui proyek pelurusan Sungai Bengawan Solo. Setelah dilakukan pelurusan Sungai Bengawan Solo timbul masalah baru, yaitu munculnya beberapa ruas bekas sungai. Pada awal tahun 2006 terjadi bencana banjir di sekitar ruas bekas sungai akibat masuknya aliran dari Sungai Bengawan Solo melalui ruas bekas sungai sehingga menggenangi permukiman dan lahan pertanian. Berdasarkan hal tersebut, ruas bekas sungai belum dikelola dengan baik sehingga menimbulkan masalah lingkungan. Penelitian ini bertujuan untuk mengetahui tingkat kerawanan banjir di kawasan sekitar ruas bekas sungai di lokasi penelitian. Metode yang digunakan dalam pengumpulan data adalah metode survei dan pemetaan lapangan serta metode skoring dan pembobotan. Skoring dan pembobotan dilakukan terhadap beberapa parameter, yaitu curah hujan, kemiringan lereng, jenis tanah, penggunaan lahan, elevasi, dan jarak wilayah dengan sungai (buffer). Zonasi kerawanan banjir didapatkan dengan metode skoring dan pembobotan berdasarkan parameter tersebut. Hasil penelitian menunjukkan di lokasi penelitian terdiri dari 3 zona kerawanan banjir yaitu kerawanan rendah sebesar 66,7%, kerawanan sedang sebesar 27,75%, dan kerawanan tinggi sebesar 5,55% dari total luas daerah penelitian.Kata kunci: Kerawanan Banjir, Ruas Bekas Sungai, Zonasi Tawangsari Subdistrict and Sukoharjo Subdistrict, Sukoharjo Regency, Central Java Province are the areas that have passed the Bengawan Solo River alignment project. After rectifying the Bengawan Solo River, a new problem arose, namely the emergence of several ex-river segments called billabong. In the early of 2006 there was a flood around the former river section due to the influx of flow from the Solo River along the former river section so that it inundated settlements and agricultural land. Based on this, the former river section has not been managed well, causing environmental problems. This study aims to determine the use of the former river section as a flood disaster control engineering. This study aims to determine the level of flood vulnerability in the area around the former river section of the study location. The methods used in data collection are survey and field mapping methods as well as scoring and weighting methods. Scoring and weighting are carried out on several parameters, namely rainfall, slope, soil type, land use, elevation, and distance of the area from the river (buffer). Zoning of flood hazard is obtained by scoring and weighting methods based on these parameters. The research area has three flood vulnerability zones, namely low vulnerability with 66,7%, moderate vulnerability with 27,75%, and high vulnerability level with 5,55% of the total area of the study area.Key words: Flood Hazard, Billabong, Zoning