Unregulated Sprawl and the Urban Flood Paradox: Analyzing the Spatial Dimensions of Urban Growth and Climate Vulnerability in Kitui Town

Abstract

Kitui Town, a secondary urban center in eastern Kenya’s arid and semi-arid lands (ASALs), has undergone rapid, largely unplanned spatial expansion over the past two decades. However, the mechanisms through which this growth intensifies local climate vulnerability remain underresearched. This study utilized a mixed-methods approach, combining remote sensing/GIS spatial analysis of Landsat imagery (2005–2025) with a descriptive survey of 384 households, 20 key informant interviews, and four focus group discussions. Findings reveal a dramatic 242.69% increase in built-up area, expanding from 12.18 km² to 41.74 km², primarily at the expense of wetlands, forests, and croplands. This expansion is strongly correlated (r=0.984r=0.984) with a 1.7°C rise in mean annual temperature, signaling a pronounced Urban Heat Island (UHI) effect. Furthermore, the study identifies an Urban Flood Paradox, where flood risk has escalated despite declining rainfall due to a 24% loss of wetlands and a surge in impervious surfaces. Planning systems were found to be operationally deficient, with only 10.9% of residents perceiving consistent policy enforcement. The study concludes that unregulated urban growth is the primary driver of climate vulnerability in Kitui and recommends the urgent adoption of Sustainable Urban Drainage Systems (SUDS) and strict enforcement of riparian buffer zones.