LANDFILL SITE SELECTION FOR THE PHILIPPINES - AN APPLICATION OF GIS IN MULTIDISCIPLINARY SCIENCE

Reynar R. Rollan¹, Emmanuel G. Ramos², Anthony P. Ferrer³, Omar B. Mendoza³, Marisol Portal\

¹ EDCOP,
²Phivolcs
³ Cybersoft Integrated Geoinformatics, Inc.
⁴ Geosphere

ABSTRACT

Taking advantage of digital data format and GIS methodologies, we have applied preset site selection criteria in the identification of landfill sites in the Philippines. Sets of parameters were initially defined under four fields—geology/landform, hydrology/hydrogeology, land-use/social conditions, and proximity/accessibility—resulting in a series of decision items for GIS processing. The topology of the GIS decision system took into consideration the various items that make a site suitable for landfill in each field, and was made to simulate results of human analysis and argumentation. The unavailability of certain data in digital format, the unevenness in the geographic distribution (map scale in analog format), the heterogeneity in the quality of available data, and the various uncertainties inherent for each data set were accommodated by supplementation, substitution, and extrapolation using auxiliary data sets. The resulting decision process was then sequentially applied to the nationwide digital data base of the Philippines with the target of identifying at least two candidate landfill sites in each of the 16 political regions of the country.

Hundreds of sites were initially identified satisfying the preset criteria, a set that was later reduced by enlarging the required area to 500 hectares to accommodate a larger buffer zone to avoid future land-use conflicts with the landfill. This final process resulted in the target number of sites per region but created a condition that restricted the identified sites to those that may also be suitable for more environmentally-restrictive use like disposal of low-level radioactive or toxic wastes.