Biophysical conditions and land use methods contributing to watershed degradation in Makueni County, Kenya

Abstract

Land use changes, rapid population growth, poverty, climate change variability and lack of livelihoods diversification aggravate watershed degradation through inappropriate land use methods resulting to water scarcity, land and water pollution, and governance issues. Soil erosion and siltation has led to land denudation, habitat loss and farm lands losing their soil fertility and compromising food security. The purpose of this study was to find out how land use methods influenced the biophysical and socio-economic conditions to accelerate watershed degradation and their effects on livelihoods in Makueni County, Kenya. The study investigated the land use methods practiced and how they affect the biophysical conditions influencing watershed degradation in Makueni County. The study used a descriptive survey research approach to obtain data on socio-economic characteristics of the study sites as well as historical trends of land use. Remote sensing and GIS was used to determine land use categories in the study area. Structured and semi- structured questionnaires were used to collect data from the community and key informants. The data collected was analysed using Statistical Package for Social Sciences (SPSS) and Microsoft Excel 2010. The study established that decline of ground water 90% (S.E=0.602 z=-0.725 sig.=0.468), increase in surface run-off 55% (S.E=0.314 z=0.394 sig.=0.693), increase in soil erosion 86% (S.E=0.660 z=-1.875 sig.=0.061), changes in rainfall and temperatures 75% (S.E=0.374 z=-0.547 sig.=0.585), decline in soil fertility 70% (S.E=0.362 z=-1.370 sig.=0.171) and drying of rivers 37% (S.E=0.398 z=1.739 sig.=0.082), contributed to watershed degradation. This predisposed farmers to adopt inappropriate farming methods and unsustainable livelihood strategies which compromised the watershed’s environmental integrity. The study made recommendations for efficient watershed management.