长江上游典型流域水土保持效益分析

嘉陵江中下游水土流失严重，是全国水土保持重点防治区，该文通过典型流域李子溪的径流，泥沙等资料分析得出：近１０年，该流域的由于生态环境的治理和保护，水土流失呈下降趋势，多年平均输沙量１９８５－１９９４年较１９６５－１９８４年减少５８．３％。因此，若将流域治理水土流失的经验和措施推广嘉陵江中下游其它地区，该区严重的水土流失定将得到明显改善。

Benefit of Soil and Water Conservation at a Typical Basin of the Upper Reaches of Yangtze River

The middle and lower reaches of Jialingjiang river with a serious soil erosion,is a major region of soil and water conservation in the whole country.A conclusion is obtained by analyzing the documents of runoff and sediment in Lizixi basin, a typical basin of the reaches.Because of taking control and protect measurement into the ecological environment,soil erosion in the basin shows a tendency to decrease in a recent decade.Comparing with sediment discharge in years from 1965 to 1984,sediment discharge from 1985 to 1994 reduced 58.3%.Therefore, if the experience and measurement of controlling soil erasion of the basin are spread to other areas of the reaches,the condition of serious soil erosion in the middle and lower reaches of Jialingjiang river will be distinctively improved