The Research On The Ecological Impact Of Hydroelectric Power Station Construction

With the development of social and economic, hydropower has also got considerable development, at the same time, ecological and environment problems received a great concern from sectors of the community. For hydropower development in terms of its ecological impact, including a lot of factors, and the interaction is also quite a lot of problems, ecological problems are mainly reflected in two aspects of terrestrial and aquatic ecosystems, and has always been the research focus of experts and scholars. Therefore, the ecological environment impact assessment study has major implications for conservancy and hydropower project.Estuarine ecological environment is the most complex area of the entire basin.Because of its specificity,the protection in the construction gains more and more attention.In the estuarine areas,the interaction between aquatic and terrestrial ecological environment lead to a unique wetland ecosystem,it takes such as the regulation of climate、degradation of pollutations、conserving water and other fuctions,has played an irreplaceable role in maintaining the ecological balance.As a type of wetland,the research about eco-environment water demand can provide an important scientific basis to its eco-environment protection. Given its importance, sensitivity and vulnerability characteristics,the estuarine ecological research is necessary.Angu project is located in the Dadu River Valley, is the final project of the Dadu River basin planning. The Dadu River downstream to import section of the river in front of the Minjiang river, the open valley, the river braided river network is relatively flat, flood land like clouds, and the Qingyi River imports. The river wetland combined with pingba terraces、coastal side beach、beach heart、land and water ecotone,totally177.73km2, including water area25.71km2, land and water alternately area11.2km2, the pingba terrace and beach area140.82km2,achieve the typical characteristics of wetland, therefore,its ecological impact assessment is one of the main content. Construction of hydropower station will lead to the water reduction,with the hydrological conditions, local climate, material energy flow and other ecological problems,even brings some irreversible changes.The research on eco-environment water demanding is of great significance to the eco-environment protection and the improvement of the utilization of water resources in this area.This article, according to the results of research at home and abroad, conbined with field surveys and local data collection, based on ecological mechanism, combined the landscape ecology and ecological mapping, wetted perimeter method,R2-Cross,evaluate the environment of terrestrial ecosystems, aquatic ecological and the wetland ecological environment about the area, and predict the impact in construction, impounding, the operation period. At last, propose the corresponding countermeasures and measures to prevent or mitigate the adverse effects, e.g. eco-environmental water demand.The results shows:1. the evaluation region has rich biodiversity, bird species achieve the first in the terrestrial animal;2. after the completion of the power station, the water depth increases, the water area will get expanded by about23.45%, island integration, the area deceased by20.57%, to more significant decrease in the beaches area;3. According to each item coupling relation, the minimum eco-environmental water demand is counted to be60m3/s;4. the evalution area owns fine state of the environment, and to strengthen the management of the process of building and construction, will reduce the irreversible effects.