The Cumulative Effect Evaluation Of Water Environment On East Route’s Intake Area Of South-to-North Water Transfer Project

Water transfer project is transforming the nature of human engineering, is on the basis of break the original natural system to construct the new system, the structure and function of the environmental system also will be so cause changes. At home and abroad, about water transfer project planning are presented to water environmental system of potential accumulation effect research is still in the initial stage, although in water transfer project planning, surveying and designing in considering the ecological environment impact assessment and environment protection design, but the general view from the argument of the feasibility, water transfer project in the process of running water accumulation environment effect research rare reports.The water transfer project cumulative effects mainly by water canal systems in the various accumulation environmental factors in single or multiple interactions caused. Water transfer project in the process of running water environment problem is it happen gradually accumulated effect, so even if the water transfer project reached the intended purpose, also can give water transfer line or water intake areas by bring more or less of water environmental hazards.Therefore, this thesis research to know and perfect the cumulative effect of water environment of the theory system and for the future of the control mode is put forward has the very vital significance.Based on extensive reading of related literature at home and abroad, summarizes and analyzes the current research achievements, in-depth analyze and research water transfer project of water cumulative environment effect mechanism and evaluation method, and put forward the classification of cumulative effects, comprehensive and detailed analyzed the cumulative effects characteristic of the water transfer project environment runoff, water temperature, water quality, sediment and aquatic animals and plants; And use the water environmental system simulation of basic theory, take east route of South-to-North Water Transfer Project as an example, through the construction and improvement of river-net water dynamic power and water quality numerical simulation model, system simulation the transfer project operation conditions of the water environment water quality accumulation effect; Finally, analyzes and evaluates the water environment and water quality cumulative effect influence of east route of South-to-North Water Transfer Project, and gives the river canal sediment accumulation effect on water quality of the corresponding feedback. The research results can hasten the model for the future and the establishment of the proposed regulation countermeasure to provide the valuable reference. This paper mainly on the following several conclusions:(1) Eastern water transfer project can greatly alleviate the uneven spatial and temporal distribution of water resources and water shortage in northern intake area, but with the water transfer project to construction and runing,13steps pumping station runing under long-term sustainability may cause runoff, water temperature, water quality, sediment and aquatic animals and plants and other aspects of water environment cumulative effects;(2) Take one-year as simulate period, according to one-dimensional river-net water dynamic power and water quality numerical simulation results, different sections of the three water quality indicators BOD5、CODMn、NH3-N concentration with monthly average drainage section of a cumulative increasing trend, and cumulative effect of the water environment will be mainly in the north intake area;(3)By reference to the PRC national standard GB3838-2002"Surface Water Environment Quality Standard" water feature and the standard classification, considering the numerical simulation results, the cumulative effect of the zero bound water threshold theory, the water environment carrying capacity, the ClassIIIwater quality indicators of water quality occurs as the cumulative effect of "trigger point" or "zero threshold", that if the divert water quality is worse than class Ⅲmay occur cumulative effect.