Using remote sensing data to monitor land cover changes near Afghan refugee camps in northern Pakistan

Abstract

By the early 1990s, the civil war in Afghanistan had forced more than three million Afghan refugees to resettle in neighboring Pakistan. Although previous studies have noted that refugees have had a negative impact on natural resources in the vicinity of resettlement camps, there has been little work done to quantify these impacts. The research presented here examines the clearing of forests in the Siran Valley, Pakistan, where 111,000 refugees were settled in ten camps between 1978 and 1993. Multi‐temporal satellite images were georeferenced using 1:50,000 scale topographic maps of the study area. A digital elevation model (DEM) was created to stratify by altitude the unsupervised classification of the two images used in the change detection analysis. The elevation data were included in the classification process to reduce the spectral confusion between agricultural and forest land cover classes. The comparison of the satellite images for the two dates show a dramatic decline of forested land. Procedures similar to those presented here can be used to assess the environmental impact of refugee movements in many environments.