Monitoring desertification risk through climate change and human interference using Remote sensing and GIS techniques

摘要

The threat of global climate change has radically increased the attention directed towards understanding the effect on environment and its natural and human induced changes. Climatic conditions along with certain human activities such as improper agricultural practices, violent use of fertilizers, overgrazing and other unsustainable practices have accelerated the conversion of fertile lands into arid lands and this eventually leads to land degradation and desertification. The term “desertification” indicates land degradation in arid, semi-arid and dry sub-humid areas resulting from climate variations and human activity. Stable degradation of vegetation cover is one of the basic characteristics of desertification process. Changes in vegetation cover of the Churu district of Western Rajasthan are very clearly detected from long term satellite data and it has been used for monitoring desertification process. In this paper, long term NOAA-AVHRR (1983-2003) data has been used to monitor desertification processes through NDVI time-trend. The study is based on the analysis of regional long term changes of vegetation conditions that indicates the ongoing desertification processes. Vegetation growth is entirely depended upon rainfall. Here, long term NDVI trend has been analysed corresponding with the long term annual rainfall (1983-2003). It identifies the areas affected by desertification process as a circumstance of climate change. The results confirmed that some parts of Churu district is under climatically induced desertification processes.