Research On The Response Mechanism Of Karst Rivers And Lakes Connected To The Ecological Environment In Guizhou Area

The river and lake water system is the carrier of water circulation and water resources formation in the basin,and is also an important support for economic development.River and lake connectivity is an important water control strategy in China.It is expected that through the artificial water resources dispatching and distribution,the river and lake ecology will be sustainable and the conditions of the river basin ecological environment and economic development will be improved.However,due to the short-term implementation of the river and lake connectivity strategy,relevant research has just started.The research on the impact of changes in water system pattern on river health and the degree of response to the ecological environment caused by water resources scheduling after the completion of the connected project is still in the exploration stage,research methods and There are many aspects to be defined such as the definition of indicators,and there is no uniform standard.Guizhou is a region with typical karst karst landform development and is also a rich place for water resources.The rocky desertification phenomenon in the karst area of ??the karst area is relatively common,the water and soil conservation capacity is poor,the watershed is ecologically sensitive and fragile,and excessive human disturbance will cause irreversible damage to the ecological environment.Therefore,it is of great significance to carry out research on the relationship between the change of water system connectivity performance and the ecological environment in karst areas.This paper selects the typical karst basin in Guizhou as the research object,carries out the investigation and evaluation work,collects and sorts through the long-term sequence data,finds the response law of ecological factors,extracts the dominant factor to establish the evaluation index system,and establishes its response relationship.The main research contents and results are as follows:(1)Collecting ecological environment-related data in the study area for nearly 20 years through various channels,and using various methods such as sliding analysis method,single-index method and comprehensive index method to analyze and study the watershed environment.The evolution characteristics and laws of the factors,preliminary detection of the response state of environmental factors,find that rainfall,flow water quality and many other indicators have a certain change,of which water temperature,evaporation,cover rate change is the most obvious.provide a reference for the selection of dominant factors.(2)By analyzing the existing research results and theoretical knowledge in China,the factor response network map is produced,showing the interaction and correlation degree between the impact factors.Combined with the evolution law and characteristics of ecological factors in the study area,through theoretical research,the water quality,DO,TP,ammonia nitrogen BOD5,pH evaporation,rainfall,flow vegetation coverage,watershed water area,landscape comfort,ecological base flow guarantee rate and water resources scheduling rationality were selected as the dominant factors..Construct a framework for the ecological impact assessment system of connectivity in the karst area.(3)Through the Delphi method and the analytic hierarchy process,the dominant factors are compared in pairs,and the mutual importance degree of each dominant factor is established to construct a judgment matrix.The weight value of each ecological impact index is obtained through calculation.With reference to the corresponding national standards and industry experience of the indicators,on the basis of analyzing the analysis of the ecological environment carrying capacity of the river and lake connected development process,each evaluation index is defined as“excellent”,“good”,“medium”,“poor” and “terrible”.Threshold level.Taking the boundary values ?of “good” and “middle”,means dry season A = 0.5864 and flood season A = 0.595,is the determined as the impact threshold of river-lake connected ecological environment assessment in karst area.(4)Taking the Wanger River water transfer project as the evaluation object,through the local visit investigation and collecting specific data parameters,the structural evaluation index system and calculation method were used to make a comprehensive evaluation of the project.It is concluded that the ecological responsiveness of the project is in a "good" state,within the threshold given by the Institute.