Study On Typical Fish Habitat Characteristics Of Water Environment In The Yangtze River Upstream Area

The river of the Yangtze river, as the first river in China and the third largest river in the world. Across the eastern and western regions in China, which has the vast area of the basin, various types of land forms. The Yangtze river plays an important role in promoting regional economic development along the river and even across the country in economic development and national ecological security. The water is remote of upstream region in Yangtze River basin, it is very rich in hydro power resources, it is of great significance to the development of Chinese energy. In addition, the Yangtze River basin is rich in aquatic biological resources, especially the fish resources is very abundant. The fish resources in The Yangtze river have an important role in the world both in the species and quantity, and the most abundant fishes endemic area in the Yangtze river upstream, which has 286 kinds of fish, due to the natural environment such as climate, which is contributed to the upper Yangtze river special river basin ecosystem, gave birth to the rich variety of aquatic organisms, famous rare fish and special fish both in the upstream of the Yangtze river. However, with the development of social economy, large-scale construction and operation of hydro power project, shipping, waterway regulation, dig sand homework, fishing and other human activity intensified, which have different influence on fish habitat, at the same time, it also changed the aquatic environment and aquatic life situation. The establishment of the upper Yangtze River rare and endemic national nature reserve, which provided important security for the natural ecological environment. The upper Yangtze River rare and endemic national nature reserve is rich in fish floating plants and animals, which provides the possibility for the diversity of the sustainable development of fishery species. The study on typical fish habitat characteristics of water environment in The Yangtze River upstream area,then put forward typical fish habitat characteristics of water environment index system, provide important technical support for the ecological restoration of water environment.In this paper, based on the hydro logical data in study area, such as flow, water level, flow, velocity, water depth, hydrodynamic data and so on, combined with the upper Yangtze river area of hydro logical situation and the position of the spawning grounds, spawning data, such as biological information and so on, Coreius heterodon, as one of the important economic fish as the Yangtze river upstream area, Being analyzed the spawning water environment and water dynamic characteristics, the relationship between Coreius heterodon spawning peak with the flow, water level, water temperature, higher water conditions such as hydro logical conditions was explored, At the same time,Analysis the relationship between Coreius heterodon spawning period with velocity, water depth was explored,the index system of water environment of fish habitat was established, which can describe water environment of fish habitat.Main researches and conclusions are as following:(1) The paper from five aspects to describe Coreius heterodon spawning grounds with index system of water environment, mainly including topography index, hydrological, hydrodynamic, water quality indicators,riverbed sediment.(2) Combined with the IHA index system, hydrological conditions associated with Coreius heterodon breeding were established. According to reserve typical hydrological data from 1956 to 2012 of Zhu Tuo station, The hydrological characteristics of Coreius heterodon breeding season were analyzed.This paper analyzed Coreius heterodon breeding hydrological index,such as flow, water temperature, rise of water level, the duration of the rising waters, etc. The results show that the Coreius heterodon breeding, Not only in the rise of water level to breed, it also spawning in the process of water level fall. Coreius heterodon spawning with the flow, water level, water temperature, higher water conditions are the indispensable factors.(3)Choose Coreius heterodon abundant resources area, from Youxi,Jiangjin to Baisha, Jiangjin spawning grounds, as the study area, Coreius heterodon spawning process from Youxi Jiangjin to Baisha, Jiangjin spawning grounds were analyzed and simulated in the yeatr 2007 and 2008, by using DELFT-3D software,through selecting spawning upstream of the river, Baisha river near the corner,straight type narrow river, the change of the velocity were analyzed, The conclusion is that the Coreius heterodon spawning process of hydrodynamic characteristics of flow velocity, water depth,from Youxi,Jiang jin to Baisha, Jiangjin.