长江流域水土流失及其防治

对长江流域水土流失现状和分布作了具体分析,指出建国以来水土流失有发展趋势;从土壤资源、土地资源、水资源与生态环境等方面,阐述了水土流失对资源环境的破坏性;着重指出了长江流域的流失物质、泥沙输移比和沉积规律与我国黄土高原流失区有着不同的特点,同时存在着比黄土高原更大的潜在危险;针对长江流域水土流失特点、发生原因并结合兴建三峡工程和长江经济带的开发,从战略高度提出了防治水土流失的策略和措施。

SOIL AND WATER LOSS AND ITS CONTROL IN THE YANGTZE RIVER BASIN

Soil and water loss is a serieus problem in the Yangtze Basin,It not only bringabout many-sided harm to soil,land and water resources,but also seriously hindersthe development of agriculture,forestry,animal husbandry and future Three Gorgeproject.As a result of the destruction exceed harnessing,from 1950's to now,both area and amount of soil and water loss are increased to some extent.The to-tal area of eroded region has been increased from 363800km~2 to 562000km~2 and the am-ount of soil loss has been raised from 1300 million to 1568 million tons.Coarse textureof eroded materials,small delivery ratio,heavy sedimentation in th upper and middlereaches and serious gravitational erosion(slide,debris flow)are the erosion characte-ristics of the Yangtze River reaches.Therefore,the soil and water loss have more greatdamages to the upper and middle reaches of the Yangtze river.Gravitational erosioncan produce more bed loads.Once they enter the reservoir region,they have formed aserious threat to the Three Gorge Engineering project.According to the soil erosioncharacteristics and soil erosion development condition in the Yangtze River Basin thispaper suggested some countermeasures and practices for controlling soil and Water los-ses.