Analisis Kerawanan Daerah Aliran Sungai (DAS) berdasarkan Geomorfometri dan Kerawanan Longsor Di DAS Bogowonto

MUNAWAROH, Dr.ret.nat. Djati Mardiatno, M.Si;Prof.Dr.rer.nat. Muh. Aris Marfai, M.Sc

2017 | Tesis | S2 Geografi

Daerah aliran sungai (DAS) Bogowonto terletak di Provinsi Jawa Tengah dengan luas wilayah 601 km2. Kondisi kelerangan yang relatif miring, intensitas curah hujan tinggi dan penggunaan lahan untuk pertanian yang intensif telah membuat DAS Bogowonto rawan terhadap degradasi lahan. Tujuan dari penelitian ini adalah menganalisis tingkat kerawanan subDAS Bogowonto berdasarkan karakteristik geomorfometri dan kerawanan longsor. Parameter geomorfometri subDAS yang berhubungan dengan kerawanan degradasi lahan dikuantifikasikan. Weighted Sum Analysis (WSA) digunakan untuk menentukan bobot setiap parameter kerawanan geomorfometri subDAS. Kerawanan longsor dianalisis dengan metode Freuency Ratio. Hasil penelitian menunjukkan bahwa subDAS Loano dan SubDAS Kodil II memiliki rangking kerawanan paling tinggi di DAS Bogowonto. Artinya, kedua DAS tersebut menjadi prioritas perencanaan dan pengelolaan DAS berkelanjutan di DAS Bogowonto.

Bogowonto watershed, located in Central Java Province, covers an area of 601 km2. It is characterized by relatively has steep slopes, high of rainfall intensity and the intensive land use for agriculture have made Bogowonto watershed vulnerable to land degradation. The aims of this research are to analyze the level of vulnerability of Bogowonto sub-watershed based on geomorphometry characteristics and landslide vulnerability. Subwatershed Geomorphometry parameters related to the vulnerability of land degradation are quantified. Weighted Sum Analysis (WSA) is used to determine the weight of each parameter of geomorphometry that vulnerable to land degradation. Landslide susceptibility was analyzed by Frequency Ratio Model. The results showed that Loano subwatershed and Kodil II sub watershed had the highest vulnerability rankings in Bogowonto River Basin. That is, the two watersheds become the priority of planning and management of sustainable watersheds in Bogowonto.

Kata Kunci : DAS,Bogowonto,kerawanan,geomorfometri,watershed,Bogowonto,vulnerability,geomorphometry