Effect Of Archipelago Estuary Utilization On Local Water Environment

Water environment as one of the most fundamental environments on the earth is the basis of human production and living.A series of water environmental problems caused by over exploitation and utilization in the estuary has become one of the most significant problems in the face of every country in the world.How to reduce the negative impact of water environment to the greatest extent while utmost developing and utilizing resources in estuary area is a problem deserves human beings to think deeply.Therefore,it has great scientific significance and practical guiding significance to forecast water environment problems caused by over exploitation and utilization in the estuary and to realize specific engineering application and engineering forecasting.So far although domestic and foreign scholars have launched large amount of research work on water environment problems in estuaries,there are little systematic analysis and researches about categorizing archipelago estuary and other similar categories and properties of estuaries into a large group,and concerns on archipelago characteristics combined with practical engineering application.Therefore,based on water environment prediction problems in archipelago estuaries combined with practical engineering applications,research work have been carried out and results achieved mainly include aspects as below:(1)This article has proposed ?archipelago estuary? and regarded it as a general classification of estuary for systaltic research.Based on characteristics of archipelago estuary,the article has proposed a series of key technologies of constructing archipelago estuary three-dimensional mathematic model including grid quality inspection technology,underwater topography seamless smoothing technology,shoal and moving boundary treatment technology,wave and current bi-directional coupling technology,model initial condition and boundary condition setting method,and model's key parameter selecting method.(2)Due to the existence of star-studded islands in archipelago estuaries,the spatial and temporal distribution of water sand and water quality environment becomes more complicated.Water quality parameters in two closely-spaced locations may be greatly different because of the impact of islands.Traditional proof technique of ?from the point to the area? mathematic model is not applicable in the archipelago estuary where islands are everywhere with swales interlaced.This article has proposed to use remote sensing quantitative inversion technology as a supplementary of mathematic model calibration and verification so as to make up disadvantages of traditional verification method.(3)With Chinese typical archipelago estuary-the Oujiang River estuary as the example,the article has established a three-dimensional water sand mathematic model,then make a comprehensive verification on the model according to actual observation data,and simulated the impact from the construction of offshore breakwater projects(Lingni north dyke as the example)on the flow conditions,sediment concentration field,the distribution of salinity,water exchange,and change of seabed scour and silting.(4)Based on the research background of Wenzhou shoal reclamation project in the Oujiang River estuary,the article has established a mathematic model of three-dimensional archipelago estuary water quality environment,studied the influence produced from constructing large-scale shoal reclamation projects on the water environment of archipelago estuaries based on good results of water flow,water temperature and water salt simulations,and then selected several water environment parameters(dissolved Oxygen,chlorophyll a,nitrogen and phosphorus,nitrogen and phosphorus in sediments,and primary productivity)for detailed forecast and analysis.