Land degradation index of tropical forest landscape in Batang Toru watershed using spatial analysis

Abstract

Forest degradation and deforestation have reduced the functions of forest ecosystem in Batang Toru watershed landscape. The degree of land degradation rate can be minimized by restoring the functions of forest ecosystem. Data concerning the degree of land degradation is needed to restore the functions of forest ecosystem. This research aims to obtain spatial distribution characteristics of land as well as land degradation index in Batang Toru watershed landscape. Land degradation was determined by using 3 variables, namely soil chemical and physical properties, as well as erosion type which occur in the site. Each variable was ranked through Likert scale. The total score of all land degradation indicators was converted into land degradation index. The study found that land degradation index in Batang Toru watershed landscape consist of very low (0,00-0,2), low (0.21-0,4), moderate (0.41-0,60 ), high (0.61-0.80) and very high (0.81-1.00). Most of Batang Toru watershed areas fall into moderate land degradation category.