Mapping Bahrain’s subsurface municipal solid waste

Abstract

The objective of this paper is to map possible subsurface dumpsites of solid waste in the Kingdom of Bahrain. Due to limited land availability, random garbage dumping for waste disposal and reclamation has occurred in the past and continues to occur in the Kingdom. Consequently, the process causes economic stress, creates environmental hazards, and contributes to the failure of many dwellings. The input data used to achieve research objective includes data from 300 boreholes, aerial photos, LandSat images, digital elevation model, and 1969–2015 land use maps. Data on the amounts and types of municipal solid waste (MSW) were collected from 1997 to 2017, as were the locations of 3665 deteriorated houses. All types of data are screened, georeferenced, and converted into geographic information system (GIS) formats. At first, a map of possible dumping areas is produced based on citizen testimonies, government engineer interviews, LandSat, aerial photos, and 1969 topo map, followed by data analysis of the aforementioned input data performed such as image classification, buffering, and others. In the next step, multi-criteria GIS algorithm was developed to identify, locate, and map possible sites. The criteria used are distances from dwelling outskirt and the shoreline, land use, relative elevation, and soil type based on borehole data. Lastly, ground truth validation assesses the accuracy of the obtained result. Overall, the study identified 101 confirmed dumping sites and 590 probable dumping sites. Site size is ranging from 18,000 m2 to 3.6 km2 distributed over 100 city blocks which are spread throughout the Kingdom. The Capital Governorate is the most affected by dumping, and the Southern Governorate is the least impacted. A comparison of results and ground observations yielded 87.5% accuracy. The proposed integrated method was effective, and the obtained identification and location accuracy were acceptable. The method can be used to identify, locate, and map random dumping sites in a similar situation.