Lecture Title:

Dynamic Changing Analysis of Eco-environment for Beijing Chaobai River Basin

Abstract:

The dynamic change of eco-environment of Beijing Chaobaihe River basin was analyzed based on the Landsat TM/ETM images from 1999 to 2005. The area of Beijing Chaobai River basin is 551588 hectares, which accounts for 33.6% of total Beijing administration area. The yearly runoff of Beijing Chaobai River is about 1022 million cubic meters, which accounts for 39.4% of total Beijing runoff. Both the area and runoff of Chaobai River are the top ones compare to all other river basin. As well as there are two reservoirs for human beings drinking in the basin. Therefore, the eco-environment dynamic change of the river basin is interested by residents, scholars, and officials.

The whole research process was divided into six steps, such as defining research goals, establishing research methods, obtaining multi-images, processing multi-images, classifying land cover, and analyzing dynamic change. The multi-images of TM/ETM from the year 1999, 2001, 2003, to 2005 were selected, and were processed by means of ERDAS software. According to the land cover characteristics of Beijing Chaobai River basin, the classification system was defined which includes three level of classes, while the first level includes three classes, such as agricultural land, constructional land, and unused land, the second level includes eight classes, and the third level includes twelve specific land cover classes. According to the classification system, the land covers of Beijing Chaobai River basin from the year 1999 to 2005 were obtained. Then, the dynamic changing analysis was done by means of GIS spatial analysis.

The main results are that from the year 1999 to the year 2005, the area of forest which includes coniferous forest land and broadleaf forest land was increased steadily as the percentage increased from 27.81% to 31.96% in 2005, which means that the eco-environment of Beijing Chaobai River basin was getting better during that periods.