Determination of collection points and optimal route for solid waste disposal in Thika Municipality using GIS

Solid waste management plays a critical role in urban development. Transportation of solid waste from point of generation to point of disposal is required to be done in minimal time to avoid accumulation of solid waste at points of generation. Uncollected solid waste poses environmental and health hazards to residents. Therefore, it is important to ensure that solid waste generated in an area is collected and disposed safely. To achieve this, there should be designated solid waste collection points to control haphazard and illegal dumping of solid waste. A pre-determined route for disposal should also be known to ensure that all the collection points are visited, and also to minimize time wastage during disposal. GIS provides tools for collection, storage, manipulation and analysis of spatial data. These capabilities can be used for management and planning of solid waste transportation. In this research, GIS was used to determine proposed solid waste collection points and the optimal route for disposal in Thika municipality. This was done by solving the location allocation problem and the travelling salesman problem using network analysis. Proposed points serving 67% of the population in Thika municipality were determined. This is an improvement over the existing collection points that serve only 33% of the population. In addition, the proposed solid waste collection points provide better spatial coverage since they serve all the sub-locations in the municipality in comparison to the existing points which cover three out of four sub-locations in the municipality. The optimal route for solid waste disposal using the proposed points is 90.38 km while the current route is 59.16 km long. Keywords: Solid waste, collection points, optimal route, location allocation, GIS , Thika Municipality