Assessment of Anthropogenic Activities and Their Impact on Ngong Hills Forest, Kajiado County: a Remote Sensing Approach

Abstract

Monitoring of the forest ecosystem is mandatory in detecting any changes in the ecosystem. Human beings are dependent on forests for various livelihood needs and thus the development and conservation of forests around the world is vital. Forests offer a variety of benefits including ecological, social as well as economic benefits thus more reason to protect this ecosystem. Forest cover change detection gives an opportunity to track the productivity, health and the forest cover as well over the years so as to enable proper management, promote conservation and enhance functionality. Optical and radar remote sensors make it possible to monitor changes by the use of various analytical techniques which include visual interpretations. The study reviewed on how remote sensing can be applied to detect change in forest ecosystem and to assess the rate of change of Ngong Hills Forest. This project is focused on determining whether anthropogenic activities are the major cause of the change in Ngong Hills Forest. Data from satellite images was analysed from 1984 to 2019 to identify the changes that occurred on the ecosystem. By achieving this, it will thus be possible for management agencies to enforce conservation because of the presence of reliable data. Landsat and Rapid-Eye images were used to inform on change detection and in this case, rapid eye data was found to be better than Landsat data in informing on change detection because of its high resolution thus high precision and better results. The changes depicted by the remotely sensed data were mapped for ease of analysis and visualization. The research depicted a massive decrease in the forest cover despite the afforestation efforts by the KFS in the 1990’s. The forest has been depreciating massively from 1995 depicting greater deforestation rates between 2010 and 2019. This depreciation has been acknowledged by the KFS as it is said to be occurring due to the anthropogenic activities mainly settlement and logging. The means of detecting change by use of remote sensing is thus able to identify the exact areas that change has occurred and thus providing insight to the Kenya Forest Service and other ecosystem protection bodies on the most affected areas and the extent of change. Once the study area is mapped, it is possible to calculate the areas that have decreased in vegetation quantity, areas where increase has occurred as well as the areas that have remained unchanged.