Impact of Human Settlement on Land Use/Land Cover Changes in the Middle River Njoro Sub Watershed in Kenya

Abstract

This study investigated the use of remote sensing and GIS in evaluating the impacts of human settlement on land use /Land cover changes. The study also investigated the drivers behind the change in the middle of River Njoro sub watershed for a period of 27 years. Drivers of land use change were captured by the use of DPSIR model where Drivers (D) represented human needs, Pressures (P), human activities, State (S), the ecosystem, Impact (I) services from the ecosystem and Response (R), the decisions taken by land users. Land sat MSS and Land sat ETM+ (path 185, row 31) were used in this study. The Land sat ETM+ image (June 1987, May, 2000 and July, 2014) was downloaded from USGS Earth Resources Observation Systems data website. Remote sensing image processing was performed by using ERDAS Imagine 9.1. Three land use/land cover (LULC) classes were established as Human settlement, forest and shrub land. Severe land cover changes was found to have occurred from 1987-2000, where human settlement increased by 52 percent, shrub land reduced by 19 percent, and forestry reduced by 72 percent. In the year 2000 – 2014, human settlement increased by 121 percent, shrub land reduced by 45 percent, and forestry reduced by 64 percent. Forestry and shrub land were found to be consistently reducing while human settlement was increasing. It was evident from the images that the LULC changes with corresponding soil quality deterioration mostly occurred in the upper and middle parts of the Middle river Njoro sub watershed which were initially under forest. To minimize the risk of vegetation destruction and soil degradation, it will be necessary to identify socioeconomic safety nets and initiate restoration of the environment to original pre- catastrophe status.