RISIKO DAN ARAHAN MITIGASI BENCANA LONGSOR DI KAWASAN DAERAH TANGKAPAN AIR KARANGKOBAR KABUPATEN BANJARNEGARA

HERLIN NATALIA DEWI, Dr. Hatma Suryatmojo, S.Hut., M.Si.; Dr.Ngadisih, S.TP., M.Sc

2019 | Tesis | MAGISTER ILMU KEHUTANAN

Indonesia merupakan negara rawan bencana hidrometeorologi. Banjarnegara merupakan salah satu kabupaten yang rawan longsor. Bencana longsor besar pernah menimpa wilayah Dusun Jemblung, pada hari Jumat, 12 Desember 2014. Dampak langsung yang ditimbulkan adalah kehilangan harta benda, korban jiwa, kerusakan infrastruktur dan kerusakan lingkungan sedangkan dampak tidak langsung adalah pendangkalan sungai, pendangkalan Waduk Mrica dan banjir di daerah hilir. Tujuan dari penelitian ini adalah menganalisis ancaman, kerentanan, kapasitas dan risiko bencana longsor di DTA Karangkobar, sehingga dapat dirancang arahan mitigasinya. Penilaian risiko dibuat dengan overlay ancaman, kerentanan dan kapasitas menggunakan Arc Gis 10.4.1, kemudian diberi skor dan bobot. Pembobotan dianalisis menggunakan Analytical Hierarchy Process (AHP) menggunakan software Expert Choice V.11. Hasil penelitian menunjukkan bahwa tingkat ancaman longsor di DTA Karangkobar 34,64 % masuk kategori ancaman rendah, 46,05% ancaman sedang dan 19,30% ancaman tinggi. Tingkat kerentanan 100 % termasuk kategori kerentanan tinggi. Sedangkan tingkat kapasitas 40,81 % termasuk kategori kapasitas rendah, 17,89 % kapasitas sedang dan 41,30 % kapasitas tinggi. Tingkat risiko bencana longsor berdasarkan aspek ancaman, kerentanan dan kapasitas adalah 14,57 % risiko rendah, 38,04 % risiko sedang dan 47,39% risiko tinggi. Berdasarkan hasil tersebut maka arahan upaya mitigasi untuk mengurangi ancaman meliputi batasan pemanfaatan lahan, penerapan agroforestri, penerapan teknik konservasi tanah dan air serta pembuatan saluran drainase. Pengurangan kerentanan meliputi program Keluarga Berencana (KB), strategi dagang, peningkatan produktivitas dan penerapan konsep DAS. Peningkatan kapasitas meliputi pendidikan kebencanaan, monitoring dan evalusi serta penerapan Pengelolaan Risiko Bencana Berbasis Komunitas (PRBBK).

Banjarnegara, a districts in Indonesia, was being vulnerable district caused by hydrometeorological disasters. A big landslide had occurred in Jemblung Hamlet on Friday, 12 December 2014. That event have direct impact,there are properly loss, death, infrastructure and environmental damage. While, the indirect impact that occurred caused by this event were siltation at the river, siltation at Mrica Reservoir and flooding in the downstream area.This research aimed to analyse the hazard, vulnerability, capacity and risk of landslide in Karangkobar catchment area to develop mitigation recommendation. The risk assessment based on overlay among hazard, vulnerability, and capacity landslides using Arc Gis 10.4.1. Then scored and weighted each parameter. The weighting was analysed by Analytical Hierarchy Process (AHP) using Expert Choice V.11 software. The results showed that hazard level in Karangkobar catchment area are 34,64% low hazard, 46,05% medium hazard and 19,30% high hazard. The vulnerability level is 100% categorized as high vulnerability. Whereas the capacity level are 40,81% low capacity, 17,89% medium capacity and 41,30% high capacity. Landslide risk based on hazard, vulnerability and capacity aspects are 14,57% low risk, 38,04% medium risk and 47,39% high risk. In this case, the mitigation direction to reduce the landslides hazard are land use constraints, application of agroforestry, application of soil and water conservation techniques and create drainage channels. Direction for reducing vulnerability are Keluarga Berencana (KB) program, trading strategies, improvement productivity and the application of watershed concepts. While the directions for capacity building are disaster education, monitoring and evaluation, also the application of community based disaster risk management.

Kata Kunci : Ancaman, Kapasitas, Kerentanan, Longsor, Mitigasi, Risiko;Hazard, Capacity, Vulnerability, Landslides, Mitigation, Risk