Comprehensive Research On Ecological Environment In Water Source Region (Nan Yang City) Of The Middle Route Project For South-to-North Water Diversion

This paper is based on the followings:(1)National Development and Reform Commission (NDRC) established a pilot project of"Remote Sensing Comprehensive Study on Land Resources in NanYang City, HeNan Province"during 1998 to 2001. (2) Land and Resources Department of HeNan Province established a project of"Comprehensive Study on the Geologic Environment of Mine in DanJiangkou Water Source Region of the middle route project for South-to-North Water Diversion"in 2004. The middle route project for South-to-North Water Diversion is the strategic significant foundation engineering which is critical to the ecosociety sustainable development and descendant's long-term benefits in 21st century and even longer time. The ecology of the water source region is very important to potable water security of BeiJing city, TianJing city and the other cities along BeiJing-GuangZhou Railway. In brief, the research on the ecological environment in water source region is of great significance.NanYang city was selected as the research area. The DanJiangKou Reservoir and the confluence area between Qi River and LaoGuan River which both are DanJiang's tributary are the important region. By the principles of"Point-and-Surface"method and"Wholes-and-Parts"method, eco-environment in this area was studied.Took two phases(1989 and 1997)of images as remote sensing data sources, and supported by image processing software and geological information system(GIS)software, land use/cover change of the water source region was studied. The classification system of remote sensing image on land use/cover was established. Remote sensing image was translated with human-computer interaction(HCI). Land use/cover charts in 1989 and 1997 were obtained and quantitatively analyzed.The appraisement about environment susceptive and ecological function of the water resource area shows that: the research area is moderate sensitivity about soil corrosion but bally about biology diversity; South of the research area, include the DanJiangKou reservoir and it's anabranches is the important headwater while northern is important protect section of biology diversity. DanJiangKou reservoir and the hill and massif around it is the important soil maintenance area.On the base of the comprehensive information of a great deal of meteorology, water resources, terrain and physiognomy, vegetation, land condition, natural disaster and environmental pollution of the study area, this dissertation has systematically analyzed the relation between these factors and the eco-environment quality of this area. During the research, one evaluation index system for the ecological environment of the study area has been established, and the analytic hierarchy process (AHP) and the other techniques were used to quantitatively evaluate the quality of the eco-environment of this area. The research results indicate that the quality of the eco-environment of this area is ordinary.Ecological environment warning was also studied on the base of the evaluation of the eco-environment of this area. The warning value will decrease to 4.97 in 2010 from 5.21,then fall to 4.84 in 2020, which indicate that the quality of the eco-environment of this area shows reverse evolution tendency, and the worsening velocity is obviously.