Hydro-Climatic Variability and Its Implications on Soil and Water Security in Kenya’s Tana Delta

Abstract

Climate change has intensified hydro-climatic variability worldwide, altering rainfall patterns, soil moisture dynamics, and freshwater availability. Across Africa, these changes undermine ecosystem resilience and threaten livelihoods dependent on rain-fed agriculture and wetlands. Within this broader frame, the Tana Delta in coastal Kenya is increasingly vulnerable to climate-driven stresses. This study examined rainfall and temperature trends, their influence on soil–water systems, and implications for community resilience. A mixed-methods design combined household surveys (n=382), focus group discussions, key informant interviews, meteorological records (1990–2020), and remote sensing techniques, including the Normalized Difference Vegetation Index, the Normalized Difference Water Index, and Geographic Information Systems were used for this study. Results show a statistically significant decline in rainfall (p < 0.05) and average warming of +1.2 °C. Wetland extent declined by 21% between 2017 and 2023, with more severe losses and salinity intrusion in lower-delta zones. Communities reported increased reliance on boreholes.  Communities reported increased reliance on boreholes, rivers and canals, though many water sources are increasingly saline. Soil degradation and reduced moisture retention have intensified water scarcity, thus undermining agriculture, pastoralism, and fishing. Household surveys confirmed that 76% of respondents experienced declining crop yields, with about 64% reporting livestock losses and 58% noted the reduction of fish catches. These findings demonstrate that hydro-climatic variability has significantly undermined soil and water security in the Tana Delta. Effective adaptation strategies such as wetland restoration, salinity management and climate-smart agriculture are urgently needed to sustain livelihoods and ecosystem services. Strengthening community-based water governance will also be critical in enhancing resilience to future climate stresses.