Applying Cellular Automata for Simulating and Assessing Urban Growth Scenario Based in Nairobi, Kenya

Abstract

Abstract-This research explores urban growth based scenarios for the city of Nairobi using a cellular automata urban growth model (UGM). African cities have experienced rapid urbanization over the last decade due to increased population growth and high economic activities. We used multi-temporal Landsat imageries for 1976, 1986, 2000 and 2010 to investigate urban land-use changes in Nairobi. Our UGM used data from urban land-use of 1986 and 2010, road data, slope data and exclusion layer. Monte-Carlo technique was used for model calibration and Multi Resolution Validation (MRV) technique for validation. Simulation of urban land-use was done up to the year 2030 when Kenya plans to attain Vision 2030. Three scenarios were explored in the urban modelling process; unmanaged growth with no restriction on environmental areas, managed growth with moderate protection, and a managed growth with maximum protection on forest, agricultural areas, and urban green. Thus alternative scenario development using UGM is useful for planning purposes so as to ensure sustainable development is achieved. UGM provides quantitative, visual, spatial and temporal information which aid policy and decision makers can make informed decisions.

Impacts of Spatial Extend and Site Location on Calibration of Urban Growth Models

“…Consequently, after successfully calibrating the three models, we compared our results with our previous modelling for Nairobi city. In Mubea, Goetzke, & Menz (2014), our modelling results were as follows (denoted as UGM 4): slope at 52, spread at 27, dispersion at 1, breed at 52, road at 2, and a weighted value of 0.9477 obtained from scenario three. Scenario three depicts a situation where we considered maximum protection of natural resources in our exclusion layer.…”

“…The ability of CA to simulate urban growth is based on the assumption that past urban development affects future patterns through local interactions among land-uses (Santé, García, Miranda, & Crecente, 2010). Thus, CA are able to simulate different urban growth scenarios (Mubea, Goetzke, & Menz, 2014).…”

“…In the second model (UGM 2), we captured the city limits of Nairobi in a rectangular fashion as shown in green in Figure 3 and Figure 4. This was a variation from previous studies in which the exact polygon boundary was applied to simulate urban growth (Mubea, Goetzke, & Menz, 2013;Mubea, Goetzke, & Menz, 2014). The region slightly captured suburban areas surrounding Nairobi.…”

“…Urban models aid in making informed decisions on land-use planning in the context of future development. Additionally, urban models have been used to simulate land-use scenarios in the view of addressing plausible agenda that fosters sustainable development (Oguz, Klein, & Srinivasan, 2007;Mubea, Goetzke, & Menz, 2014).…”

A Novel Modeling based Agent Cellular Automata for Advanced Residential Mobility Applications

“…In a bottom-up approach, systems are considered as result of all smallest units' actions. Among these bottom-up approaches, cellular automata (CA) have been widely used for modeling and simulating infrastructure layer of urban areas [5], [20]- [23]. CA to project spatial forms of an urban area, it abstracts land field using a lattice of discrete cells, and presents the overall behavior from simple local rules.…”