Assessment of Desertification Dynamics in Machakos County, Kenya

Mark Kipkurwa Boitt,Patrick Ambi Odima

doi:10.13189/ujg.2017.050204

Abstract

Many countries face desertification as a challenge, and Kenya is not an exception to this. Desertification means an intensification of desert like conditions and a decline in biological productivity. The Princeton University Dictionary defines it as “the process of fertile land transforming into desert typically as a result of deforestation, drought or improper/inappropriate agriculture”. Desert areas are usually sparsely populated, because it is very difficult to carry out most productive human activities such as farming, and also due to the harsh weather conditions. Often, desertification leads to the migration of human and animal populations to more productive areas. This causes overpopulation in the more productive areas, giving rise to more problems. Remote Sensing techniques have proven to be effective, and have been used worldwide for environmental studies. The availability of free data from satellites such as Landsat has provided a cheap and efficient method of conducting such studies. Thus it is necessary to use current, efficient and cheap methods such as Remote Sensing technology in order to assess desertification trends in the country. Many parameters have been used globally to assess desertification, and those used in this study include NDVI (Normalized Difference Vegetation Index, TGSI (Topsoil Grain Size Index) and Albedo. The aim of this research was to assess desertification dynamics in Machakos County, Kenya. The period of this assessment was between 1990 and 2010. It is realized that desertification can be mapped using the methods of NDVI, TGSI and Albedo. Environmental, human and social activities are factors that determine the desertification of a given area or region.

Highlights

Desertification has been defined by the United NationsConvention to Combat Desertification (UNCCD) as "land degradation in arid, semiarid and dry sub-humid areas through natural processes as well as human activities”
Mapping from entirely remote sensing techniques coupled with Normalized Difference Vegetation Index (NDVI), Top Soil Grain Index (TGSI) and surface albedo is what we experiment in this paper
Topsoil Grain Size Index (TGSI) and NDVI were reclassified into two classes each, Low (1) and High (2)

Summary

Introduction

Convention to Combat Desertification (UNCCD) as "land degradation in arid, semiarid and dry sub-humid areas through natural processes as well as human activities”. Human activities such as agriculture, overgrazing and deforestation are been considered as parameters that causes desertification with both physical and socio-economic impacts [1]. A desertification monitoring system for sub-Saharan Africa was developed and it uses mainly the continental-scale remotely sensed data [2]. Several approaches have been developed to use to map desertification. Mapping from entirely remote sensing techniques coupled with NDVI, Top Soil Grain Index (TGSI) and surface albedo is what we experiment in this paper

Objectives

Methods

Results

Conclusion