Research On Water Security Under The Impact Of Human Activities In Pearl River Delta

The river and estuarine topography and hydrologic environmental conditions in the Pearl River Delta have been changed dramatically under the impact of such intense human activities as large-scale bridges and ports construction, disordered mining, land reclamation in the estuary, occupancy of the flood land during the high degree process of urbanization, which results in the frequent occurrence of the flood disasters in recent years. The flood disasters and the water environmental pollution are the main reason which causes the complexity of the problems in various aspects as flood control, water supply, water quality, water ecology and so on in the Pearl River Delta region. Water security problems such as abundance, lack and dirtiness have become the critical influencing and restricting factors for the improvement of the quality of people's lives and the sustainable economic-social development in the Pearl River Delta region.In this paper, a large number of the first-hand and the latest or newer data about the network river in the Pearl River Delta, for instance, river hydrology, topography, construction projects concerning with river, system construction for flood control and relief, and the distribution of the water taking and supply, pollution discharge into the river, are collected. The extensive and thorough investigation in the Pearl River Delta has been accomplished for the water security problems on the flood control, water supply, water quality and so on in recent years.1D-2D coupled hydrodynamic and water quality mathematical model of the river network and estuary of the Pearl River Delta is established. Systematic research on the three core problems for water security above has been carried out in combination with the operation mechanism of the social water cycle from the three dimensions as an entirety for the first time. And the important theoretical basis and technical support are provided from the research above for the protection of the economic and social sustainable development, solution to the contradiction between supply and demand of water resources and the realization of the effective management of water resources redistribution.This dissertation includes6chapters, and the details are as follows:In chapter1, the specific problems for water security in the Pearl River Delta are analyzed with today's common water security crisis faced by human society to explain the significance and necessary for the topic selection research. The research status and the development trend of the hydrodynamic&sediment and water quality mathematical model at home and abroad are generally summarized, especially in the Pearl River Delta. The research direction, contents, approach and characteristics of this dissertation is briefly introduced.In chapter2, a1D-2D coupled hydrodynamic mathematical model of river network and estuary of the Pearl River Delta is established, which provides the basic tool for the research of water security above and is calibrated and verified based on measured data. The coordinate and elevation system of the underwater terrain of among the river network, estuary and adjacent sea area is unified by the technology of coordinate transformation and surface fitting conversion for water depth. At last, a new method for the model verification by digital buoy which is used to trace the physical buoy in the natural river is discussed. The digital buoy tracing method is possessed of definite application value for the verification of hydrodynamic mathematical model and can be used to verify the model in the spatio-temporal simultaneity way and performs an important role in perfecting and developing the hydrodynamic mathematical model.In chapter3, both the hydrological situation and its evolution of upstream inflow, water stage and diversion ratio and the topographic change of river channel etc. in the Pearl River Delta is analyzed. The process of network river evolution is studied by the two phase of spatio-temporal simultaneity way with the multi-angle and multi-level. A new understanding of security for flood control in the Pearl River Delta is obtained. And corresponding suggestions&countermeasures on the water conservancy modernization construction for Pearl River Delta region even for Guangdong Province is proposed base on above-mentioned research results.In chapter4, the full-caliber economic&social water supply and consumption mathematical model is established to calculate and analyze the balance between the water supply and consumption within the computational cell. And the full-caliber quantity of both water supply and consumption in2011is obtained. And the reliability and accuracy calibration of the results is improved effectively by the balance calculation. On the basis of the analyzing large data, the characteristics of structure and region distribution for water supply and consumption in the Pearl River Delta is studied. A new method with river training project for water resources redistribution in the Pearl River Delta is proposed to explore an effective way for the water supply security.In chapter5, the current situation of pollutant emission and water quality conditions in the river network of the Pearl River Delta is analyzed. And the natural water environmental capacity, ideal water environmental capacity, available water environmental capacity and the permitted emissions of pollution is calculated based on the sources of pollution, the layout of the sewage outlet and the target of water quality protection. The emission reductions and available environmental capacities are constructive discussed combined with the preliminary judgment to the water quality and ecological security of the river network base on the pollution discharge status quo. The corresponding counter measures are put forward in order to ensure the water quality and ecological security of the river network in the Pearl River Delta.In chapter6, the whole paper is summarized. The water security issues and measures for flood control, water supply and water quality are analyzed and evaluated comprehensively. And the further prospective study is pointed.