Use of Geo-Information Technologies in Predicting Urban Growth Trends; an Integrated Simulation Approach:

Abstract

Many urban areas exhibit different growth patterns spanning from linear development, transit-oriented development, concentric zonal development to multi-nuclei development patterns. In today’s world, main urban areas present themselves as Central Business Districts (CBDs), that double up as mixed use commercial and residential areas, which serve majority of the population who live in and around them. Ideally, the CBD sites – for most cities around the world, were identified before any development took place, making it easier for the local authorities, urban planners and surveyors to demarcate and plan for sustainable development. Most, if not all jobs, are located in these urban areas, making these employment areas, urban growth hotspots. Decentralization of the traditional city was not only paramount for the survival of the CBD, but also necessary for creating new urban areas, which were relatively smaller than the CBD and played a significant role in shaping the urban spatial structure. The presence of multiple urban areas in a region contributes to, strengthening national competitiveness, social cohesion, service delivery, socio-economic integration and balanced regional development. When there is a shift from functional specialization of the CBD to economic specialization of the surrounding urban areas, this brings about changes in the economic processes and evolution of transport networks which are the foundation of urban growth and expansion, as in the case of Rhine Main Region in Germany. In Kenya, most of the known urban areas, like Limuru Town, emerged as traditional markets in the 1900’s and grew to modern urban areas and municipalities that we see today. However, urban growth has been accompanied by rapid land use changes and sporicidal growth of informal settlements. As a result, urban areas growing in Limuru Central Ward, are deprived of basic infrastructure, land use harmonization and spatial synergies. This study therefore attempts to explore the use of GIS and Remote sensing technologies in observing past and present urban growth trends, which should be done prior to predicting sustainable urban planning. The findings from this study are expected to contribute to the knowledge of simulating how urban centres can be planned in the present to cater for the future spatial and infrastructural needs of the growing urban population. Predicting urban growth trends introduces more practical ways of spatial planning and policy development in developing countries, through spatial analysis and modelling using GIS and Remote Sensing technologies. As a result, the study has uncovered that some of the factors that have affected the rate of urbanization in Limuru Central Ward include, slope and elevation, existing clustered urban development in specific areas especially near Limuru Town or along the existing transport network, and availability of infrastructure especially the road network which plays a key role in determining how accessible urban areas are in the study area. The impact of urbanization in Limuru Central Ward between 1999 and 2019 has been identified as; significant decrease in land occupied by bare soil and vegetation, rapid land use changes to accommodate more built-up spaces, sporadically growth of clustered development or dense built-up areas, and the need to expand infrastructure in newly developed areas to promote accessibility. Prediction of urban development in the study area between 2020 and 2050, shows that in the future, the urban footprint is likely to increase near existing urban areas, especially along the transport networks and near existing built-up areas such as schools. The urban footprint may likely adopt a mix of urban growth models – such us the multi nuclei and sector models, however, majority of the urban areas may most likely be located within proximity to the transport network – transport-oriented development.