The Change of Yeyahu Wetland Resources in Beijing
WANG Ying1, 2, GONG Huili1, 2, ZHAO Wenji1, 2, LI Xiaojuan1, 2, ZHANG Zhifeng1, ZHAO Wei2 (1. Key Lab of 3D Information Acquisition and Application, MOE, School of Resource and Environmental Science, Capital Normal University, Beijing 100037, China; 2. Key Lab of Resources Environment and GIS, Beijing City, Beijing 100037, China)
Wetland, considered as a natural ecosystem and landscape style, has great resource potentiality and environmental function. For a long time, the change of wetland landscape pattern posed by human activity has not only changed the existing wetland function, but also exerted influence on wetland environment. This paper focuses on the fusion of Landsat-TM image with IRS image in Yeyahu wetland for getting color images with higher resolution. Combined with on-the-spot investigation, we set up interpretable symbols, carry out image vectorization, spatial analysis and data statistics using ArcGIS 9.0, and then analyze and research vegetation cover changes and changing characters of Yeyahu wetland resources during the period 1998-2004. The result shows that the decrease of water area leads to the reduction of vegetation and species, non-point pollution in agriculture, and water resource scarcity. On the basis of the above-mentioned technological trajectory and research approaches, we identify the changing characters of wetlands, utilize the principle and method of accumulating effect to propose restoration measures. For the protection of environment, it is necessary to return lands to nature, get back the swamps, and utilize and exploit wetland resources with rationality.