Environmental Impact Assessment Of Water Conservancy Project Development

The construction of water conservancy projects,especially the cascade development of avionics,has a great impact on the ecological environment of rivers and the lower reaches.The Jialing River is an important tributary in the upper reaches of the Yangtze River.Its tail reservoir connects with the Tongzihao Power Station in Wusheng,Sichuan in the upper reaches and the Caojie Power Station in Hechuan,Chongqing in the lower reaches of the shipping hub.It is rich in water resources for development.It is one of the main channels of the Yangtze River system and listed as an important war readiness channel in the upper reaches of the Yangtze River by the state.The Jialing River nourishes the surrounding urban clusters and oases,and its ecological environment is of vital importance,especially the water ecological environment.The Lize Water Conservancy Project on the middle reaches of the Jialing River is under construction.The dam axis of the project is about 32 km north of Hechuan City.The normal water level is 210.72 m,the total storage capacity is about 620 million m,the installed capacity of the power station is 74MW(4×18.5MW),and the average electricity generation for many years is about 317 million k W · h.The waterway and ship lock are of Ⅳ class,the navigable buildings of the project are designed according to 500 T class ships,and the hub project is of sub large(2)type.The impact of cascade development on the water ecological environment is extremely complex and diversified.It is necessary to systematically study the changes of ecological elements in the Jialing River basin before and after the construction of Lize Water Conservatory Project,and to analyze and predict the impact of avionics construction on the ecological environment.Based on the detailed investigation of the natural and ecological environment of the Lize Water Conservatory Project on the Jialing River and the collection of basic data,The relative changes of the ecological environment caused by the construction of the Lize water conservancy project on the jialing river were found through the comparative analysis of the current situation monitoring of water quality and environment,aquatic ecological investigation and evaluation,the discharge in the river,the water temperature,the silt in the river,the river form and the aquatic and terrestrial flora and fauna.The relevant achievements are as follows :(1)After the completion of the Lize Water Conservatory Project on the Jialing River,it has a certain impact on the downstream water ecological environment,the water ecosystem in the reservoir area and the land ecosystem.After adopting the corresponding ecological environmental protection measures,the impact is within the range that the ecological environmental system can bear.(2)Through the calculation and analysis of the ecological hydraulics algorithm and Tennant algorithm,it is clear that the ecological discharge that can be passed by the Lize Hydraulic Project on the Jialing River is 188 m /s,which is when the water is stored in the initial stage.In general years,the discharge of ecological flow can meet the requirements of 188 m /s.In exceptionally dry years,the upstream volume Tingzikou Reservoir is required to carry out ecological dispatch to guarantee the discharge of ecological base flow and meet the requirements of ecological water in the downstream of the hub.(3)The shrinkage of aquatic habitat will be formed after impounding water.At the same time,the reproduction of indigenous fish,the unfavorable habitat and the decrease of the population will occur,and the fish population will also transform from indigenous fish to small and exotic fish.The presence of plankton and benthic organisms in the area may increase in the short term.(4)By alpha experience discrimination as well as to the seed of tung tree trenches,grass street vertical reservoir water temperature observation results of analogy analysis,benefiting for temperature hybrid power station reservoir large reservoir,vertical water temperature stratification phenomenon does not exist,at the same time,the drainage of water temperature of reservoir and the water temperature of river in the area of basic consistent,reservoir or the water temperature will not be impact on downstream.