长江流域水资源、灾害及水环境状况初步分析

PRIMARY ANALYSE OF WATER RESOURCE, DISASTERS AND ENVIRONMENT IN THE CHANGJIANG RIVER CATCHMENT

长江是我国第一、世界第三大河流 ,发源于青藏高原 ,全长 6 30 0多公里 ,流域面积 180× 10 4km2 ,占中国陆地面积的 1/ 5。长江及其流域不仅以其不可替代的自然资源优势和其他江河无法比拟的区位优势 ,在我国国民经济和社会发展中扮演着举足轻重的角色 ,特别是约占全国的 36 %、拥有 96 16× 10 8m3 的年径流量 (为黄河的 2 0倍 ) ,是我国最重要的水源地。这不仅对长江流域资源优势的发挥和缓解我国北方地区日趋严重的水资源短缺问题至关重要 ,而且对全国的可持续发展也将产生深远影响。然而 ,在长江流域大规模开发及经济快速发展的同时 ,人类活动与自然规律的负面效应相互叠加 ,导致了流域环境的生态调节和自我恢复功能大幅降低 ,引起了日趋严重的水环境退化、洪涝灾害威胁加剧等问题。文章首先对长江流域水资源的重要性及其作用做了分析 ,肯定了其丰富的资源和重要的战略地位 ,该流域在占全国不足 18%的土地上 ,集中了 4 0 %以上的人口及国民生产总值 ,而且其经济地位有进一步上升的趋势 ,在水量及水能的蕴藏上 ,全流域湖泊面积达 10 32 3km2 ,占我国淡水湖泊总面积的 37.2 % ,水能蕴藏总计达 2 .7× 10 8kW。另外 ,对长江流域日趋严重灾害及水环境问题做了探讨 ,尤其中游的洪水。

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.