Drivers of Urban Sprawl Along River Rupingazi Ecosystem, Embu County, Kenya

Urban sprawl is commonly associated with the outward expansion of built-up areas into peripheral and environmentally sensitive locations. This study examined the drivers of urban sprawl toward the Rupingazi riverine zone in Embu Municipality, Kenya, and assessed associated land-use and land-cover (LULC) changes between 1989 and 2019. Data were collected from 398 residents using structured questionnaires, supplemented by key informant interviews, google satellite images and field observations. Descriptive statistics were used to assess residents’ perceptions of the drivers of urban sprawl, while ordinal logistic regression was employed to determine the statistical association between the identified predictors and the ordinal measure of urban expansion. The regression results showed statistically significant positive coefficients for proximity to the river (β = 0.710, p < 0.001), lack of strict zoning regulations (β = 0.680, p < 0.001), housing shortages (β = 0.546, p < 0.001), and population growth pressure (β = 0.502, p < 0.001). The LULC analysis further demonstrated substantial spatial transformation along the Rupingazi riverine zone. Vegetation cover declined from 4.61 km² (69.11%) in 1989 to 2.82 km² (31.58%) in 2019, representing a substantial reduction in vegetated land. In contrast, built-up areas increased from 1.97 km² (29.54%) in 1989 to 6.04 km² (67.64%) in 2019, indicating a marked expansion of urban development into areas previously dominated by vegetation. The findings demonstrate that urban sprawl along River Rupingazi is associated with proximity to the river, weak zoning regulation, housing demand, and population pressure, with the observed LULC changes providing spatial evidence of the expansion of built-up areas and decline in vegetation. The study recommends strengthening land-use planning and development control, enforcing zoning regulations, improving housing provision, and establishing continuous GIS and remote-sensing-based monitoring of urban expansion in environmentally sensitive riverine areas.