Laporkan Masalah

PENATAAN RUANG BERBASIS RISIKO BENCANA BANJIR LUAPAN SUNGAI COMAL HILIR DI KABUPATEN PEMALANG, PROVINSI JAWA TENGAH

YUNUS ARIS WIBOWO, Prof. Dr. rer. nat. Muh Aris Marfai, M.Sc., Dr. M. Pramono Hadi, M.Sc.

2017 | Tesis | S2 Geografi

Analisis risiko banjir luapan Sungai Comal hilir di Kabupaten Pemalang Provinsi, Jawa Tengah dirancang untuk menyusun basis data bencana banjir dan menyusun arahan penataan ruang berbasis risiko banjir. Risiko banjir disusun dari analisis tingkat bahaya banjir dan tingkat kerentanan. Bahaya banjir disimulasikan dalam kala ulang lima, 10, 25, dan 50 tahun menggunakan HEC-RAS dan ArcGIS berekstensi HEC-GeoRAS. Kerentanan banjir diperoleh dari skoring parameter-parameter kerentanan sosial, ekonomi, fisik dan lingkungan. Arahan penataan ruang ditentukan berdasarkan evaluasi rencana pola ruang terhadap risiko banjir dan disesuaikan dengan penggunaan lahan eksisting. Hasil penelitian menunjukan tingkat bahaya banjir pada kala ulang lima, 10, 25 dan 50 tahun didominasi oleh kelas bahaya rendah dan sangat rendah. Tren peningkatan luas genangan dan kedalaman banjir terjadi pada kelas bahaya sangat tinggi dan tinggi pada setiap kala ulang banjir. Tingkat kerentanan terhadap banjir luapan Sungai Comal hilir didominasi oleh kelas rentan sedang dengan luas 10832,15 hektar (49,68%). Tingkat risiko banjir pada kala ulang lima, 10 dan 25 tahun didominasi kelas risiko tinggi, sedang, rendah. Sedangkan pada kala ulang 50 tahun didominasi oleh kelas risiko sangat tinggi, tinggi dan rendah. Arahan penataan ruang meliputi 16 kombinasi pengelolaan ruang secara struktural dan non-struktural. Kata kunci : Risiko banjir, HEC-RAS, Model Hidrologi

FFlood risk-based spatial planning on downstream of Comal River in Pemalang Regency, Central Java was designed to generate the flood disaster data and determine the spatial planning based on the river flood risk. The flood risk was generated from the flood hazard and vulnerability analysis. The flood hazard was simulated for five, 10, 25, and 50 years by using HEC-RAS and ArcGIS with HEC-GeoRAS. The flood vulnerability was generated by scoring process of the parameters of the social, economic, physical, and environment vulnerability. The spatial planning was determined based on the evaluation of the spatial planning toward the flood risk and adjusted with the existing landuse. The results showed the Comal River downstream flood hazard levels in five, 10, 25, and 50 years return period were dominated by high and very low level. The rising trend of the inundation width and the flood depth occured for very high and high levels in every return period. The vulnerability level toward Comal River downstream flood was dominated by the moderate level comprised 10832,15 hectares (49,68%). The flood risk in five, 10, and 25 years return period were dominated by the high, moderate, and low level. While the river flood risk in 50 years return period were dominated by the very high level, the high level, and the low level. The spatial planning comprised of 16 combinations of structurally and non-structurally spatial management. Keywords : Flood risk, HEC-RAS, Hydrologi modelling

Kata Kunci : Risiko banjir, HEC-RAS, Model Hidrologi