Modelling of land use and land cover to predict future water demand and inform infrastructural planning in the Kampala Water Service Area of National Water and Sewerage Corporation

Abstract

Land cover is a fundamental variable that impacts many parts of the global environment. Changes in land cover can have far-reaching consequences at local and global levels, therefore monitoring the changes of land use and land cover of the earth’s surface is important in achieving continual and precise information about a study area for planning and development purposes. Geographic Information System (GIS) and remote sensing technologies have shown great capabilities in studying land use and land cover changes and were thus employed to assess spatiotemporal dynamics of land use/land cover in the Greater Kampala Metropolitan Area (GKMA). This area has experienced urban growth and hence undergone rapid land use transformations leading to land cover changes. This aim of this study was to model the urban sprawl in GKMA, so as to appropriately plan for infrastructural development in order for NWSC to fulfil its mandate of supplying potable water to the population in Kampala Water Service Area, whose operational area is the GKMA. Land Use Land Cover change was detected by using multi-temporal satellite image data for 2010, 2015 and 2021 in order to produce land cover maps, and this was used to assess the direction and magnitude of urban sprawl in GKMA. These, coupled with drivers that influence land cover changes were subjected to a model to predict future scenarios. Both proximate and underlying causes were considered as driving factors of land cover change, and these included the population growth in GKMA, the distance to existing water distribution infrastructure and customers, the terrain of the area and distance to existing road network. The Cellular Automata-Markov model embedded in TerrSet software was used to simulate the trends of land use and land cover change during the period of 2010 to 2015 and 2015 to 2021, and a future land use map for 2040 was simulated based on these transitions. Since NWSC prioritises infrastructural expansion as a way to increase service reliability, the outcomes of this study can provide scientific based data to support decision making in regard to capital developments in infrastructure.