Spatial And Temporal Changes And Driving Forces Of Wetlands In Haihe River Basin Based On RS And GIS

Wetland is one of the ecosystems with richly bio-diversity. It located in the transition zone between the land and the aquatic ecosystems. It has some characteristics of the land and the aquatic ecosystems.In the history, the worlds'wetlands ecological systems has been seriously destroyed by human activities. The biological diversity was declining, with functionality degraded. It has profound significance for wetland conservation and sustainable use, to carry out the analysis of wetland temporal and spatial changes.The study area is Haihe River Basin, located in North China, now facing serious ecological environmental problems, such as the serious shrinked in wetland area, wetlands pollution, fell of the ecological service functions. In this paper, the Landsat MSS / TM / ETM+ remote sensing image data that covered the study area, acquired on 1980s,1990s,2000,2008 were used. The human-computer interaction method was used to extract the wetlands thematic information between 1980s and 2008. And the Dynamic degree was used to analysis the change of the study area wetlands. Finally, the northern rivers basin and Baiyangdian wetland was chosen as typical case study areas.a. We proposed the Haihe River Basin wetlands definition and classification system. It is useful for long-term wetland treatment in this basin. And Object-oriented classification method was applied to Baiyangdian wetland land cover classification. It greatly reduced the manual works, and improved the classification accuracy and reliability.b. We analyzed the 1980s, 1990s, 2000 and 2008 wetland changes, get the discipline of the wetlands distribution in Haihe River basin and trends of wetland changes in the last 30 years. Prior to 1990 the wetlands increased. In 1980s and 1990s, the total wetland area is 8851.75km~2 and 10090.48km~2, respectively. After 1990, the trends showed a significant reduction. The wetlands area in 2000 is 9205.95 km~2. In 2008, the wetland area dropped to 8830.24 km~2.c. We taken the typical area northern rivers basin as an example, to calculated landscape pattern indices. And analyzed the characteristics of the landscape pattern changes of the study area. Prior to 2000, wetlands less interfered by human. After 2000, due to the human activities intensity increasing, wetlands were greatly degradated。d. We applied the Object-oriented classification method to classify Baiyangdian wetland and calculate the area. And analyzed the characteristics of Baiyangdian wetland land cover mutual transformation by the transfer matrix. The results showed that: wetland area tended to shrink, 1964 have 407.3 km~2,2002 reduced to 274.63 km~2. Ups and downs of wetland water is obvious, the water in 1964 is wider, to 346.75 km~2 . However, 10 years later, it is reduced to 94.65km~2; On 1983 and 2002, the water area continue to shrink, water surface area are 67.27 km~2 and 46.86 km~2, respectively.e. For the comparative analysis of different impacts on the wetland changes, we used natural factors such as temperature, precipitation, humidity, groundwater. the human factors we used are population, social, engineering. The analysis results showed that, during the study period, the main reason to cause wetland changes in the study area is regional climate changes, followed by social and economic changes.