Landfill site suitability using geographic information system and analytical hierarchy process

Abstract

In solid waste management, landfilling is the lowest ranking of waste management, but it is still widely practiced because it is convenient and consumer friendly. Unfortunately, many landfill sites have closed and this is a main issue in solid waste management. The purpose of this study is to suggest suitable and potential sites for landfill in Johor Bahru area through mapping technique and database system by using parameters that had been identified. Landfill site selection is a complex task because it needs to consider many criteria including economic, social, geological and environmental criteria. Analytical Hierarchy Process (AHP) is a method for analysis and supports decision where multiple and competing objectives are involved and multi alternatives are available. AHP is grouped in Multi Criteria Decision Analysis used to analyze landfill site suitability method. An extensive literature study on previous landfill site selection was conducted. Fifteen parameters were identified to use in AHP process. In this method, the process is divided into hierarchy before pair wise comparison was done and the result is prioritizing according to their weightage. The process is continued with weightage evaluation and its consistency. Landfill site selection process involved many spatial data and strenuous in handling it. Thus, Geographic Information System (GIS) can give significant help because it can potentially handle large volume of data that need to be evaluated and processed. The method used in GIS is digitizing, buffering and overlays. As a result in AHP, the most important criterion is river weighted 0.149 or 14.9% of all criteria and the least important criteria are distance to main road weighted 0.028 or 2.8% of other criteria. In GIS method, there are six parameters selected which are main road, plantation, residential area, swamp, grassland and river coverages. The findings identified two potential sites for landfill area because it satisfied all given requirements. As a conclusion, integration of GIS and AHP is suitable to be used in landfill site selection process.