Hydropower Development And Ecological Security Evaluation In Nayi River Basin

Ecological security is a major issue that must be maintained and retained in the survival and development of human society.The hydropower development was impacted for the ecological security is extensive,long-term,cumulative and lagging,and may even be irreversible in the basin.This study takes the Nayi River Basin as the research object,based on the evaluation system,conducts field research on the plant resources,vegetation resources,animal resources and land using status in the basin,according to the survey results from the landscape ecosystem,biological resources.social economy and ecological security,the expert evaluation method was used to objectively evaluate the hydropower development projects of the Nayi River Basin,and to analyze the environmental problems and environmental protection experiences that occurred in the Nayi River hydropower development,which can provide experiences for future ecological safety assessment and other project construction.The main findings are as follows:1 The evaluation score of the impact of the hydropower development project on the landscape ecosystem is 24.15,and the impact level is a minor influence,which the ecosystem of alpine and deciduous broad-leaved mixed forest ecosystem of Boniodendron minus(Hemsl.)T.Chen and Myrsine semiserrata Wall.,and the ecosystem of Liquidambar and Lysidice rhodostegia Hance evergreen deciduous broad-leaved mixed forest are unique ecosystem type in China.The construction of the project makes the change of the landscape type area less than 1%,which is slightly affected.The construction of the project will affect 26 landscape patches.After completion,6 plaques would be disappeared.The 20 landscape patches was remained,which only was decrease or increase slightly.The number of landscape patches would be changed less than 1%,which would not lead to any landscape disappeared in the basin.The project construction will cause forest loss of 9.17hm2,and forest coverage would be decreased of 0.02%,forest coverage would be changed less than 1%,and the impact also is small.2.The impact of hydropower development projects on biological resources mainly includes three aspects:The impact score on the biome(habit)is 28.5,and the impact level is minor impact.The impact score on the population/species is 23.25,and the impact level is minor impact.The impact evaluation score for the main protection object was 17.0 points,and the impact level is minor impact.3.The hydropower development project has a socio-economic impact evaluation score of 54.75,and the impact level is moderate.4.The impact of the hydropower development project on ecological security is 52.5 points,and the impact level is moderate.Hydropower development projects would inundate some of the plants and affected the habitat of wild animals.The construction of the reservoir leads to reduce the aquatic organisms.The land area was occupied by the construction and was submerged of the reservoir in total 1.86hm2,which changed the land resources and land use patterns of the evaluation area.The construction of the project provided convenience for the spread of the highly invasive Eupatorium adenophorum of outside the project area.At the same time,genetic resources are lost as the individual species disappear.The impact index of the project construction on the ecological security of the river basin is 29.26.According to the grading standards of the impact degree,the impact level of the project on the Nayi River Basin is:minor impact.