Effect Of Large Water Project On The Key Ecological Functional Region In The Middle And Lower Reach Regions Of Yangtze River

Effect of large water project on river ecosystem study at home and abroad is reviewed and analyzed, habitat elements which influence important biology resources in Yangtze River are systemically expatiated in the whole and theory. Ecological functions and actions of different river morphology and topography are analyzed. A deep research on changes of the hydraulic and hydrological characteristic in the middle and lower reaches of the Yangtze River has been done.Combined river ecosystem theory, morphology and topography of river ecosystem are presented. River morphology and pattern are classified. Ecological functions and actions of different river morphology and pattern are analyzed. Combined spawning grounds reach of Chinese sturgeon four famous Chinese carps, the hydraulic and hydrological characteristic of different kinds of river modality are expatiated. Relation and effect of river morphology and topography and biodiversity are discussed.According to the effect of the Three Gorges and Gezhouba on the key ecological functioning region- Chinese sturgeon spawning ground in Yangtze River, ecological effect and biology effect of flow change of river hydrological process and characteristic are discussed. Typical hydrology station—Yichang is taken as an example to research. Hydrological process changes before and after Gezhouba construction is analyzed, the result indicates that there are close relation among Chinese sturgeon spawning time, flow during flood period and spawning, some hydrological conditions is required for biology reproduction. Chinese sturgeon spawning needs some flow range. Flood periodically changes is a signal to biology around river, these biology reproduce, span, migrate according to it.Because of large water project construction in the Yangtze River and human action effect, some important fish resources are stressed. Starting with microhabitat in key functioning region in Yangtze River, hydrology and hydraulics simulation are used, an analysis on river structure, riverbed, velocity of flow distribution and other impact factors of Chinese sturgeon spawning ground are analyzed. 2D flow model has been established. To supply Chinese sturgeon spawning ground materials restoration with reference, through Survey in spawning ground, riverbed materials form is classified, and grain size distribution curve is rendered.