VALUASI EKONOMI TINGKAT KERUSAKAN BANGUNAN PERMUKIMAN AKIBAT BANJIR LAHAR DI KALI PUTIH KABUPATEN MAGELANG

Abstract

Abstract
The purposes of this study are to identify the zonation of lahar-affected regions and the
number of damaged houses due to lahar, as well as to make an economic valuation on
settlement building damage due to lahar in Kali Putih, Magelang Regency.
The study was conducted by using a survey method based on physical and administrative
zonations. The former was based on overflow width of lahar in Kali Putih after the Merapi
erruption in 2010, while the latter was based on subdistrict. Each of the zonation units was
sampled. The sampling was carried out on the basis of settlement building vulnerability due
to lahar. The sample was represented by 59 respondents and three times of Focus Group
Discussion (FGD) during the study.
Results of the study show that, first, the overflow width of lahar in the location of study was
1.785 km2. The widest overflow was in Sirahan Village, i.e. 0.813 km2 or 45.532 %, and the
narrowest one was in Blongkeng Village, Ngluwar Subdistrict, i.e. 0.001 km2 or 0.057%.
Second, the number of houses affected by lahar was 1,290 houses. Settlement building
damage was dominantly due to collapse/washed away (814 houses), moderately damaged
(200 houses), ligthly damaged (140 houses), severely damaged (71 houses), and relatively
undamaged (65 houses). A settlement mostly affected by the impact of lahar was Sirahan
Village, Salam Subdistrict, i.e. 860 houses. Third, the largest lost resulted from the lahar
was related to permanent houses, i.e. approximately IDR104,000,000.00 because the
construction cost for the permanent houses was more expensive than that for semi-permanent
and non-permanent ones.