Ecological function regionalization, one of the important methods for conducting geographic spatial division, is based on environmental resource, ecological sensitivity, and spatial differentiation of ecological service functions.By using this method, an entire area can be divided into several different ecological function regions.Based on an analysis of the basic features of the ecological environment of the Chaohu Lake Basin of Anhui Province, China, the principles, basis, methodology and nomenclature of ecological function regionalization have been determined.The purpose is to clarify ecological environmental problems and fragile areas, and to provide scientific grounds for environmental protection and the planning of construction, ecological security, rational use of resources, and industrial distribution of the studied area.
As the sub-valley is an independent geographic unit within the entire basin, its ecosystem has ecological integrity from upstream to downstream.Thus, conducting monitoring and management of regional ecological environments in sub-valley units is of great importance to the conservation and ecological restoration of regional ecosystems.However, most sub-valleys cover multiple economic or administrative units, and thus it is difficult to obtain the thematic information of the ecological environment for each sub-valley.The superiority of RS and GIS is embodied fully here.The advantages of data collection and multilayer superstition are made full use of for solving the difficult problems of ecological information extraction.The data for the research include: 1:50000 basic digital geographical data of the Chaohu Lake Basin, such as data layers of river systems, residential areas, railways, administrative divisions, and contour lines; digital data layers for resources and environments derived from the vectorization of 1:250000 soil type, land type, and land use maps; and 1:100000 land use maps interpreted from Landsat TM images from January 11, 2009.The above data layers are tested and updated from Landsat TM images.
Through extraction of land use information from remote sensing data and sub-valley divisions from DEM analysis, this research discusses the methodology of sub-valley ecological function regionalization in the study area, based on the application of RS and GIS technology.The ecological function regionalization of the Chaohu Lake Basin was established and five ecological function regions and 12 sub-regions determined.The dominant factor of the first-level ecological function region is the boundary of the sub-valley, reflecting the general pattern of ecological function with the sub-valley as a unit.The dominant factor of the second-level ecological function region is the land use type.However, characteristics of landform or climate, ecosystem type, and ecosystem service function should also be embodied.The second-level ecological function region is the basic unit of ecological function type, reflecting the differentiation of ecological function inside the first-level division.The focus of ecological protection and the economic-social development constraints of each ecological function region were also clarified.
The above technique reduces costs greatly and improves the accuracy and efficiency of the graphics, realizing the classic graphical principles (e.g., principles of the dominant factor and superposition) excellently.This study has important realistic meaning for integrated management of the ecological environment of the Chaohu Lake Basin, and provides scientific grounds for comprehensive control of the ecological environment, industrial distribution, ecological hazard prevention and reduction, environment protection, and the planning of construction in this area.