Urban Expansion and Loss of Agricultural Land: a GIS based study of Kiambu County

Urbanization leads to the outward expansion of cities and results in changes in land use and the dramatic effects are very clear in peri-urban areas. A key challenge of the urbanization process is the rapid conversion of prime agricultural land to urban land use (residential, industrial, and infrastructural construction) in the urban periphery. The present study attempts to understand the spatiotemporal extent of urban expansion and its implications on land use, by using remote sensing and GIS tools to detect land use/cover changes in a peri-urban setting over 28 years. Land use and land cover (lulc) maps were derived from Multispectral images of 1986, 2002 and 2014 from Landsat Thematic Mapper, Enhanced Thematic Mapper and Landsat 8. The study revealed a significant change of land-use/cover between 1986 and 2014 with the area experiencing a rapid increase in urbanization (41.6 %), forest decreased by (10.3 %), and a decrease in bare land (1.8 %), water (0.22 %) and agricultural area (29.3 %). Agricultural in 28 years is losing to urbanization with the results showing that 61.5 % of agricultural land converted to built-up land. The findings provide a useful support for land-use planning and management. In addition, provides the inputs to decision makers that must balance trade-offs between the positive benefits of land-use change and negative unintended consequences. The study calls for a combined approach, which involves participation of all the stakeholders in management and planning of land as a vital resource. This approach will protect the endangered land use, agricultural land, and controlling urban developments.