Analyzing Land Cover Change Using Remote Sensing and GIS: A Case Study of Gilgit River Basin, North Pakistan

Abstract

Mountainous areas of northern Pakistan are rich in biodiversity, glaciers and key watershed of Indus River system which provide ecosystem services for their inhabitants. These regions have experienced extensive deforestation and are presently vulnerable by rapid land cover changes, therefore an effective assessment and monitoring is essential to capture such changes. The aim of this study is to analyze the observed changes in land cover over a period of thirty-nine years, divided into three stages (1976-1999, 1999-2008 and 2008-2015). Four images from Landsat 2 Multispectral Scanner System (MSS), Landsat 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper and Landsat 8 Operation Land Imager data were obtained to detect land cover change. This study used supervised classification-maximum likelihood algorithm in ERDAS imagine to identify land cover changes perceived in Gilgit River Basin, Pakistan. The result showed that the range land, glaciers, water bodies, built-up/agricultural cover are the major categories that have been altered by the natural and anthropogenic actions. In 1976, built up/agriculture, range land, water bodies and glacier cover was 1.13%, 45.3%, 0.66% and 13.2%, respectively. Whereas in 2015, built up/agriculture, range land, water bodies and glacier cover was 3.25%, 12.7%, 0.91% and 8.2%, respectively. Theses land cover shifts posed acute threat to watershed resources. Therefore, a comprehensive watershed resource management is essential or otherwise, these resources will deplete rapidly and no longer be capable of playing their role in socioeconomic and sustainable environmental development of the area.