SPATIAL TEMPORAL ANALYSIS OF THE IMPACTS OF CLIMATE VARIABILITY AND LAND USE LAND COVER CHANGE ON MAIZE YIELD IN KENYA

Abstract

The Agricultural sector is most susceptible to climate variability and change, especially in Africa because it primarily depends on rainfall, and the adaptive capacity is low. Increase in population and urbanization as well as unsustainable farming practices have influenced land use changes leading to diminishing croplands. These two factors; climate variability and land use land cover change have intensified food insecurity in Kenya which depends on only 20% of its land area for agricultural production. It is therefore crucial to enhance the understanding of land use and land cover change impacts coupled with climate variability dynamics on agricultural productivity. This study examined the spatial temporal impacts of climate variability and land use land cover change on maize yield in Kenya for the period of 2012-2020. The maize yield data used was obtained from the Kenya maize yield Database while Precipitation, Maximum temperature and Minimum Temperature data was obtained from the Climatic Research Unit gridded Time Series (CRU TS) which has a spatial resolution of 5° latitude by 0.5° longitude. Land Cover Type Product (MCD12Q1) offered by MODIS was obtained from the USGS website. ArcGIS 10.8 and Microsoft excel were used in the analysis. The non-parametric Man-Kendell and Sens slope tests showed no trend in the data with a p value > 0.05 for T-max, T-min and Precipitation. Spearman rank correlation test showed that a strong positive correlation between maize yield and the climatic parameters for the, Lake Victoria Basin, Highlands East of Rift Valley, Coastal Strip and North Western Regions. In all the four regions, except T-max for the Coastal Strip, the R² is 0.5 and above while the p value is <0.05. The results of the Land use land cover classification showed that open shrublands increased significantly in area by 11,229km2, closed shrublands by 4365km2 and Barren land by 4145 km2. On the other hand, grasslands recorded the highest decrease in area of about 7235 km2 followed by croplands, 4414km2 and Savannah 4116km2. The findings suggest that climate variability in the study area has a significant impact on maize yield for four out of six climatological zones as evidenced by decline in precipitation trends for the MAM season which is the long rainy season. Land use and land cover changes also have a negative impact on maize yield through decline in croplands by 4414km2 from 2011 to 2020.