Research Of Wetland Changes And Driving Force In Tumen River Basin For The Past 50 Years

Wetland, which is the special natural integration of wet creatures, wet environment, forests and oceans form the three global ecosystems. It is an important natural resource and is one of the most important environments for human survival as well. It not only offers the raw materials for human life and human production but also plays an important role in improving weather condition, flood storage, pollution control and reducing other environmental pollution. Therefore, it is called "kidney of the earth". However, due to increased human activities and people's inadequacy of knowledge on the functions and values of a wetland, most of wetlands are unreasonable exploited and destructed in last few decades.Wetlands, from the very beginning, are the targets of land development. Reclaiming lands from lakes and exploring a large-scale agricultural development in wetlands make wetland landscapes tremendous change and cause serious environmental problems as well. These problems finally draw great attention. More and more research covers on the relationship between human activities and changes of landscape patterns of wetlands as well as the climate. For example, Sanjiang Plain Wetlands, Red Forest Wetlands, Tibetan Plateau Wetlands, the Yellow River Delta Wetlands, Tarim Wetlands and so on have become the research hotspots in recent years. However, the research on dynamic changes of wetland landscapes in Tumen River Area is still in initial stage.With the technical support of geographic information systems, remote sensing, the 1:50,000 topographic maps, Corona image, MSS/TM image and Alos image, this paper has collected the information of wetlands in Tumen River Area by using remote sensing image software process. It analyzes the distribution, the growth principle, landscape pattern and the changes of the wetlands in last 50 years with the concept of landscape ecology, a dynamic degree, transfer matrix and the landscape pattern index. It tries to help up master the wetland types and the spatial distribution of the wetlands in this region in time. It also explains the dynamic changing process and rules of the wetlands, reveals what causes the changes of the wetlands, and populates the database in the region for the national wetlands data. Studying the dynamic changes and the relationship between these changes and the natural surrounding environment as well as the socio-economic development can help enhance the protection of wetland resources and management.The result shows the following features:1) The man-made wetlands including paddy fields, reservoirs and etc. Increase significantly according to its way of changing; yet the natural wetlands including swamps, lakes and rivers are decreased constantly.2) According to the changing characteristics of wetland types, a large of natural wetlands are changed into man-made wetlands and non-wetlands, and a large of non-wetlands are changed into paddy fields.3) According to the change of wetland landscape pattern, the numbers of landscape patches, landscape fragmentation index and landscape evenness index increase, but the average patch areas, landscape diversity index are decreased.4) Human factors are the main driving forces of causing the reduction of natural wetlands in this area, among which agricultural activities is the most important impact.5). The wetlands ecological function retrogression, edge effect significant,decline in biodiversity, soil nutrients reduces, as a result of natural wetlands were greatly broken.