The Effect Of Economic Development Of Zhujiang Delta On The Water Environment At Zhujiang Estuary

In this article, the author discusses the historical progress of economic development of Zhujiang Delta in recent 20 years. And on the basis of the collected social and economic parameters, the author analyzes the situation of economic growth, the structure of industry, the increase of population and the development of marine resources at Zhujiang Estuary. Analysis shows that the economic development of the region can be divided into two periods, namely the pioneering period in 1980s and the highly growing period in 1990s. In these two periods, the industrial structure obviously changed, the first industry continuously declined, and the second and third industries steadily went up and occupied the leading position. Marine industry moved towards to multiplicity step by step and began to take shape. At the same time, process of urbanization unceasingly quickened, reaching 72.7% at present. Zhujiang Delta has become a zone of city group in which multiple industrial belts are located together. Due to natural increase of the population, as well as millions of people rushed in this area for work, Zhujiang Delta has turned into one of the highest population density cities. This brings a lot of problems to environment of the region.Perennial supervising data of the eight main mouths of Zhujiang Estuary indicates that the pollutant content and flow flux to the sea changed yearly, heavy metals and oils (representing industrial sewage) dropped, but inorganic nitrogen and COD (representing domestic sewage) went up yearly, and leading position of industrial sewage was gradually replaced by domestic sewage. Calculation of pollutant capacity ratio of the eight main mouths of Zhujiang Estuary is also identical. Why does this situation appear? The reason is that the Guangdong government put its major work on the control of the industrial sewage, and the standard rate of industrial sewage treatment continuously rose. But because of quick process of urbanization and industrialization, rapid increase of population and lag urban infrastructure construction, the average domestic sewage treatment rate does not reach to 20%. This causes the discharge capacity of sewage go up yearly.Through statistical analysis of the supervising data of water quality at Zhujiang Estuary in recent years, and using the fuzzy method of water quality grading and water pollution comprehensive index to further evaluate and classify the water quality of Zhujiang Estuary, the author discovers that water quality of Zhujiang Estuary can be divided into three periods, that is class III in early 1980s (the starting year for statistics),class I~II in 1980s and class IV or above in 1990s. The comprehensive pollution index shows a high-low-high changing mode, and its curve is like U form, in conformation with the raising of the industrial sewage treatment rate and the lag domestic sewage treatment. This situation indicates the water pollution at Zhujiang Estuary is changed from industrial pollution type to living pollution type.In order to understand the quantification relations between economic growth and environmental pollution and on the basis of the perennial statistical materials in Guangdong Yearbook, the author proposes a mathematical mode of Environment Kuznets Curve (EKC). The result indicates that in early 1980s, the EKC curve of average GDP (PGDP) as well as discharge capacity of industrial sewage of Guangdong present a reverse U. This illustrates the process of industrial sewage pollution from worsening to control along with economic growth. It started moving towards to favorable economic development with low industrial sewage pollution. But domestic sewage as well as total discharge capacity went up along with economic growth, and EKC curve presents straight line. This indicates Guuangdong Province has not yet cast off the situation of high economic growth with high water pollution.Finally the author puts forward some specific measurements for source control and new concept of using green GDP to replace traditional GDP in judging the economic development of the region.