Ecological Function Regionalization For The Sihe River Drainage Area

Ecological function regionalization aims at confirming ecological functions of different regional units on the basis of analyzing eco-environment characteristics, ecosystem services and space differentiation rules of ecological sensitivity after the investigation of eco-environment. Ecological function regionalization is the foundation of the zone management for regional eco-environment. The process of ecological function regionalization can provide scientific proofs for formulating eco-environment protection policies, maintaining regional ecological security and nursing regional eco-environment and it can provide administration information and tools for environment management and decision-making departments, too. Ecological function regionalization on Sihe River drainage area can not only provide a basic pattern for ecological function regionalization on the whole Nansihu lake drainage area, but also it can propel enhancement of eco-environment, improve life quality of local residents, promote regional economy development, solve the contradiction between basin water quality guarantee and coordinated development of local economy and society, and realize synchronous development of economy, society and environment.On the basis of field investigation and data collection, ecological principles, together with qualitative and quantitative methods are applied in this paper to analyze eco-environment and evaluate eco-environment sensitivity and the importance of ecosystem services of Sihe River drainage area, together with space differentiation rules are announced here. Consequently, combined with the developing characteristics of its economy and society, Sihe River drainage area can be divided into 2 ecological sub-regions and 8 ecological function regions. According to the eco-environment characteristics, main eco-environment problems and ecological functions of each ecological function regions, key tasks and specific measures on ecological nursing and construction are put forward. The main conclusions of this paper are listed as follows.(1) There are rich ecosystem types and there also exist regional eco-environment problems in Sihe River drainage area. The space-time location of water quantity is not well balanced and is influenced greatly by precipitation. What's more, some rivers have been polluted in different levels. Water shortage has turned up in some regions. And influenced by human activities such as mining processes, water loss and soil erosion is very serious in some regions. Structure of the forest is irrational even if the forest cover rate is high.(2) From the spatial distribution patterns of eco-environment sensitivity of Sihe River Drainage area, soil erosion sensitive regions are mainly distributed in the mountainous and hilly areas in the upper reaches, with Quanlin town as the largest distribution area; geological hazard sensitive regions are mainly distributed in the southeastern hilly areas of the basin, with Sizhang town, Miaoguan town, Chengqian town and Tianhuang town as the main distribution areas; and water environment pollution sensitive regions are mainly in the northwestern areas of the basin.(3) From the spatial distribution patterns of ecosystem services, the most important regions of ecosystem services are mainly distributed in eastern mountainous and hilly areas with Quanlin town as its center, in northern hilly areas with Shimenshan and Longmenshan as its centers, in southern areas with Nishan national forest park and Nishan reservoir as its centers, in western plain areas with three holes: Confucian, Confucius Temple and Konglin as its center, and there are still sporadic distributions in central areas of Sihe River drainage area.(4) GIS technology is applied in this paper to divide Sihe River Drainage area into 8 ecological function regions by mixing and analyzing all kinds of data sources. Eco-environment sensitivity, ecosystem services and the already existing problems in each ecological function region are analyzed. The development directions of 8 ecological function regions are put forward at last.