Temporal And Spatial Variation Of Water Environment And Its Impact On The Ecosystem Of The Pearl River Estuary

The Pearl River estuary was selected as the research location in this paper. Theoretical analysis, field survey as well as ecology mathematic simulation were employed to reveal the variation features of water environment of the Pearl River estuary in recent 20 years and researches with the interrelation and interaction of water environment and aquatic biology of the estuary. The main conclusion of present thesis listed as follows.(1) Evolution course of the Pearl River estuary indicated that the deposits of "sand flat" were being accelerated. The development of the delta formation presented distinct characteristics such as notable stage, diversity of formation, and the unbalance of depositing.(2) The resources and ecological environment of wet-land had been deteriorated by those unreasonable human activities, such as the water pollutions, land applications, destruction of vegetable, and the excessive exploitation of natural resources. The main ecosystem problems lay in the destruction of ecosystem structure, the declines of the function of ecosystem and the eco-diversity, and the eco-productivity, and so on.(3) The original construction of the coastlines of Pearl River had been changed by those large scale regulated actions of this area, which caused significant negative influences on the water environment. Not only the capacities and the spaces for the reception and degradation of pollutants in this area, but also the sites and the velocity of the pervasion for pollutants were all affected greatly.(4) The fluxes of the main rivers of Pearl River changed slightly from 1957 to 2000. Additionally, The increasing of the exploitation of water resources didn't cause significant variations of the fluxes of Pearl River.(5) The Pearl River had been polluted seriously, with the main pollutants of organic matters, ammonium, nitrate, nitrites, and volatile hydroxybenzene. Most of the pollutants of in Pearl River exhibited an increasing trends of deterioration in the latest 20 years. The highest increasing velocity of pollutants concentration was found...