Socio-Economic Dynamics and Land Use/Cover Changes within Nairobi and Ruiru Catchments in Kenya

Land cover change remains one of the major most factor exacerbating ecosystem changes. This study investigated the effects of socio-economic drivers on land use and land cover (LULC) changes in the Nairobi and Ruiru catchments in Kenya over the period from 1990 to 2022. Utilizing remote sensing data and GIS-based LULC classification techniques, the study achieved high classification accuracy, with kappa coefficients consistently exceeding 0.80 and overall accuracies ranging from 86% to 97%. The analysis reveals significant spatial and temporal changes in LULC, with forests and perennial crops dominating the upper and middle catchment zones, while shrubs and grasslands were prevalent in the lower zones. Land use and land cover changes were accompanied by substantial transitions in land cover types, with significant portions of forest areas being converted into perennial crop farms and shrublands into urban areas. Socio-economic factors were identified as the major drivers of land use and land cover changes. The study area observed increase in area under coffee and tea from approximately 14% in 1990 to the current 25% a situation attributed to increasing population and favourable government plans. Urbanization emerged as the most significant driver of LULC change, particularly in the Nairobi catchment, where urban land cover increased by over 400%, from 3.1% in 1990 to 15.5% in 2022. The Ruiru catchment, while also experiencing urban growth, showed a more modest increase, with urban land cover rising from 1.0% to 3.2% over the same period. The rising population coupled with improved transport network in Nairobi led to emergence and sprawling of major settlements like Kawangware, Kangemi, Kariobangi among others. In the recent past, catchments such as Ruiru river have observed decline in coffee zones owing to conversion of coffee farms along major roads to settlement and trade zones. The increased accessibility and trade across other towns in the metropolis remains a threat to planned developments. The study underscores the profound impact of socio-economic factors, particularly in land use dynamics for catchments with rapidly growing urban expansion. The findings highlight the need for sustainable land management and urban planning strategies to mitigate the adverse environmental impacts and ensure balanced and transformative development.