Great River Downstream Wetland Hydrologic Characteristics Of The Evolution And Ecological Responses

Water is the key element of an ecosystem. Suitable hydrological conditions are the foundation which a wetland ecosystem depends on for existence. The evolution of wetland hydrological characteristics would change the characteristics of a wetland ecosystem.Water conservancy construction and the change of land use make the protection of Daqinghe downstream wetland facing a severe situation. The major work of this paper selected Daqinghe downstream wetland as the study area, while Beidagang and Tuanbowa wetlands as typical ones. According to the theories and methods of Hydrology and Wetland Ecology, with the support of RS and GIS technologies, based on the statistics and analysis of hydrological changes, a comprehensive analysis of the changes of the wetland ecosystem was made, including the changes of wetland landscape, water quality, and wetland biology. Then wetland protection measures were brought forward. The results of research provided a scientific basis for the protection of Daqinghe downstream wetlands, which has been applied to"The study of the impact on wetlands of Duliujianhe training".The results showed that: under the interference of human activities, especially large-scale water resources development and utilization, the water source of Daqinghe downstream wetland had a substantial reduction from1960s, the ground water level decreased continuously meanwhile. Due to the shortage of water resources, the wetland landscape changed fundamentally. In the past 15 years, human activities made the wetland landscape diversity index decrease, the degree of evenness of spatial distribution uniform decline, and the degree of fragmentation increase. Wetland plants degraded with the lack of water resources, and had the the trend of salinization. In the past 15 years, inter-annual changes of vegetation growth and water area had a collaborative inter-annual changes. The relationship between vegetation growth and water area was the parabola. The reduction of wetlands water and the deterioration of water quality reduced the diversity and the number of wetland animals.According to the results, the measures were put forward: using water resources rationally in the region, transferring water outside of the region when it is necessary , and establishing the guarantee mechanism of wetland ecological water as soon as possible are effective ways of ecological improvement and restoration of Daqinghe downstream wetland.