PRIMARY ANALYSE OF WATER RESOURCE, DISASTERS AND ENVIRONMENT IN THE CHANGJIANG RIVER CATCHMENT
长江流域水资源、灾害及水环境状况初步分析

Changjiang River originated from Qinghai Xizang Plateau, with a length of 6 300km, a basin area of 180×10 4km 2(almost 20% of the whole country area), is the longest river in China and the third in the world. It plays an important role in our social economy development because of its unique advantages in natural resource and region position. It is also the most important water resource in China; the total water resource of the annual runoff capacity is 9 616×10 8m 3 (by 20 times more than that of Yellow River) and is about 36% of total budget of the country. How to make good use of its resource is not only for buffering the status of lack water resource in the North China, but also affecting the sustainable development strategy of the country. However, with the large scale exploitation and economy development, influence of human activities combining the negative aspects of the nature makes the ability of bisecholoyical regulation disaster and self restoration function become weakly. As a result, water environmental deterioration and flood disaster become more and more serious. This paper, made a primary analyse of the significance and function of water resource, and affirmed its abundant resource and great potentical use. More than 40% population inhabited here and almost 40% GDP produced with less than 18% land of area of the country. Water energy reaches 2.7×10 8kW with a total land falling of 5 400m. There are 437 rivers of which the drainage area is more than 1 000km 2. Lake area within the catchment adds up to 10 323km 2, 37.2% of the total area of fresh lakes in our country. This paper also discusses the increasing water crisis, especially the flood and environmental problems. The characters of flood is determined by rainfall patterns. For heavy rain in summer the flood brought large losses with total stricken population of 7.33×10 8 in the Changjiang River catchment(not including Taihu lake). The total losses in economic can reach up to 711×10 8 Chinese Yuan from 1959 to 1990. About 4.7×10 8 tons silts had been bought to the estuary every year. At the same time, water bio pollution and eutrophication are becoming se rious in the catchment with the output of contaminated water of 189×10 8 tons in 1998 and 234×10 8 tons in 2000 which is 34% of that of the whole country. At last this paper suggests that to protect Changjiang River, to recover its water and well balanced ecological system, to make human beings and nature harmonious exist, to pursue sustainable development, are urgent tasks for the economic development and environmental protection in the Changjiang River catchment.