Analisis Risiko Banjir dengan Pendekatan Participatory Geographic Information System (P-GIS) Di Wilayah Perkotaan Kecamatan Muara Lawa Kabupaten Kutai Barat Provinsi Kalimantan Timur

FLORENSIUS STEVEN, Prof. Dr. H.A. Sudibyakto, M.S

2012 | Tesis | S2 Geo-Informasi untuk Manajemen Bencana

Tujuan penelitian ini adalah (1). mengidentifikasi tingkat bahaya banjir dan menyusun peta bahaya banjir, (2). menilai tingkat kerentanan elemen berisiko terhadap banjir, (3). menilai kerentanan infrastruktur maupun dampak yang dapat meningkatkan kerentanan elemen berisiko dan menerapkan P-GIS dalam analisa risiko bencana banjir. Metode penelitian menggunakan metode survei lapangan dengan melibatkan masyarakat yang ada di daerah rawan bencana (Participatory GIS) sebanyak 103 rumah tangga dengan pengambilan sampel secara non acak (purposive sampling). Data primer yang dikumpulkan dari rumah tangga meliputi peristiwa banjir tahun 2010 (frekuensi, durasi, ketinggian banjir, luas genangan), kondisi sosial ekonomi, struktur bangunan, persepsi dan kapasitas menggunakan kuesioner dan penilaian tingkat risiko banjir secara kualitatif. Posisi responden direkam koordinatnya dengan GPS kemudian dispasialkan. Data sekunder meliputi data curah hujan, peta Rupa Bumi Indonesia (RBI), peta penutupan lahan, peta administrasi. Hasil penelitian diketahui terdapat empat wilayah tingkat bahaya banjir yakni tidak bahaya, bahaya rendah, bahaya sedang dan bahaya tinggi, berdasarkan hasil penilaian tingkat risiko banjir terdapat tujuh rumah tangga (6.80%) berisiko tinggi, tiga puluh empat rumah tangga (33.01%) berisiko sedang, lima puluh rumah tangga (48.54%) berisiko rendah dan dua belas rumah tangga (11.65%) berisiko sangat rendah. Bangunan Tipe tiga memiliki kerentanan tertinggi sebesar (63.11%), sedang (21.36%) dan rendah (15.53%). Berdasarkan penghitungan dengan skala Likert, tingkat persepsi sebagian besar klas sedang (64.08%) dan tingkat kapasitas masyarakat tertinggi pada klas sedang (61.17%). Berdasarkan periode ulang bencana banjir, tingkat bahaya banjir di Wilayah Perkotaan Kecamatan Muara Lawa tinggi dan cenderung sangat tinggi

The research aimed at: 1) identifying flood hazard and constructing flood hazard map; 2) assessing vulnerability of elements at risk; and 3) assessing the vulnerability of infrastructures along with possible impacts brought about by infrastructures failures on the elements at risk’s vulnerability. Implementing Participatory GIS method underlined the pursue of research objectives. The research involved survey to 103 households in District of Muara Lawa who were selected purposively. Households survey covered the data on 2010 flood events (frequency, length of inundation, water depth, flooding extent), socio-economic condition, buildings type, risk perception, and capacity. Secondary-sourced data included map of Rupa Bumi Indonesia (RBI), daily rainfall data, map of land cover, and map of administrative area. The research classifies the area into four classes of risk degree, being extremely-low risk, low risk, moderate risk, and high risk. As great as 6.80% of the area belonged to high risk class, 33.01% of the area belonged to moderate risk class, and 48.54% and 11.65% of the area belonged to low and extremely-low risk class, respectively. Vulnerability assessment of buildings in the area resulted in buildings with wood wall and floor material to be the most vulnerable. As great as 63.11% of buildings in the area belonged to this vulnerability group. The other 21.36% and 15.53% of buildings belonged to moderate vulnerability and low vulnerability group. Predominantly, community perceived the area to be moderately risky to flood (64.08%). On the other hand, the predominant level of people’s capacity in facing flood events was found to be moderate (61.17%). Seen from the short return period, the threat of flood to the region was perceived high.

Kata Kunci : Risiko, bahaya, banjir, kerentanan, kapasitas.