Landscape Dynamics in Relation to Slope and Elevation in Garo Hills of Meghalaya, India using Geospatial Technology

Abstract

Garo hills region of northeast India is severely affected by sheet erosion mainly because of the age old tradition of shifting cultivation in the fragile hill slopes aided by other anthropogenic activities. Slope and elevation are important parameters that provide varieties of topographical feature for ecological patches. Vegetation is one of the major factors controlling soil erosion, while most soil erosion occurrences are due to the removal of vegetation and topsoil. Change matrix result indicates dynamic character of landscape.The present study is conducted to examine the landscape dynamics to relate vegetation cover with slope and elevation in three Garo hills districts of Meghalaya using temporal remote sensing data of 2001 and 2010. It is revealed that there is decrease in open forest during the study period while areas under dense forest and non-forest increased. This increased forest areas are confined in the high slopes which are inaccessible. Considerable portionsin the vulnerable slopes are utilized for shifting cultivation which could be devastating. The present study shows more than a double fold increase in shifting cultivation in the high altitudinal area which is negative sign in terms of environment protection. Conversion of dense forest to open forest occurred in all the slope categories while alteration from open to dense forest predominated in the moderate and high slope categories. Maximum change from open to non-forest is in the slope categories of moderate andlow. There is considerable change from current jhum to open forest mostly in the moderate slope category. The maximum exchange between dense to open and open to dense occurred in the moderate slope and elevation areas.