Engineering geology-based land zoning at the location of Piyungan landfill development plan, special region of Yogyakarta

Abstract

After operated more than 20 years, Piyungan landfill has already in full capacity because it has exceeded its technical age. Constrained by the difficulty of finding new land, the government, eventually, determined the development of new landfill in the area of ±1.9 Ha near Piyungan landfill. This research aims to determine whether planned area is an appropriate area for the new landfill. The research method is divided into three steps, which are; (1) collection of secondary data relating to geology and geological hazards, (2) primary data collection by conducting geological mapping to identify rocks and geological structures, geological mapping to identify rock mass, groundwater depth, and rock permeability test, and (3) Land suitability analysis by applying Boolean Logic in the multi-criteria spatial analysis. The land suitability analysis reveals two alternative locations for the new landfill area surrounding the existing Piyungan landfill. First, alternative location 1 located in the north to northwest of the landfill site and included in the administrative area of Sitimulyo village, Piyungan District with an area of 3 hectares with an elevation of about 115 meters above the sea level. Second, alternative location 2 which is adjacent to alternative location 1, where is on the west of the landfill and is a border area administratively included in the territory of Bawuran village, Pleret District with an area of around 13 hectares with an altitude of 75 to 87.5 meters above the sea level. On other side, result of suitability analysis show that the goverment planned location of new landfill categorized as not feasible area due to steep slope (>20%) and closed to a geological fault.