Study of Eco-Environment Monitoring in Arid Area Based on Multi-Source Multi-Temporal Remote Sensing Images and GIS

The ecological environment which human existence depends on is more and more under threat due to our own over consumption of water resources. Desertification of land and shrinkage of oases are ubiquitous in droughty area. Various structural and non-structural measures have been taken to hold back such environment deterioration, such as peremptory water transfer. In this paper the downstream region of the Tarim River has been.chosen as the test area. In the 7^th decade of the last century, many reservoirs were built on the upstream of the river for irrigation purposes. Due to the increased water diversion on the upstream, river flow disappeared on the downstream and the downstream natural conditions became worse since then. The river basin authority then decided to send water downstream through compulsory means to protect the downstream eco-environment. Water from upstream reservoirs and lakes has been diverted to downstream several times since 2000. In order to evaluate changes of the downstream eco-environment before and after the water transfer, especially changes in the size and vegetation cover density of the downstream oasis, analysis was conducted in this study. Remote sensing is found to be an efficient tool in such investigation due to its multi-resource and multi-temporal characteristics. Image data collected from MSS, TM, CBERS-2 and MODIS are used to study the land cover changes. Through overlaying and buffering analysis in the GIS platform, a relationship between vegetation and water resource has been established. The result will be of significance to more efficient natural environment protection and more reasonable water resource allocation for this river basin in the future.