豫境汉水流域水土流失特征及其治理对策

Soil Erosion Features and Harnessing Countermeasures of Hanshui River Basin in Henan Province

豫境汉水流域的水土流失面积占土地总面积的34.4%,以轻度和中度侵蚀为主,有面蚀、沟蚀和重力侵蚀3种类型,其中面蚀主要发生于坡耕地区,沟蚀主要发生于海拔500m以下的丘陵区,重力侵蚀主要发生于暴雨中心区.较为严重的水土流失,导致了诸多方面的危害,例如破坏耕地,减少耕地面积,导致肥力下降;淤塞水库和河道水体,降低蓄水和航运效益;植被覆盖率下降,环境恶化,洪水和干旱灾害频繁发生.水土流失的成因主要是地势陡峻,降雨量大,暴雨集中;过度开垦荒地,坡耕地比例较大;过度伐林放牧,植被破坏较为严重,植被覆盖率较低;采矿筑路施工过程中防护不力,诱发水土流失.针对上述水土流失的特征和成因,应采取政策、法规、行政、经济和技术等多方面的具有针对性的对策加以治理.

The area of soil erosion of Hanshui river basin in Henan province makes up 34.4% of the total area of the land, and the soil erosion belongs mainly to mild and medium erosion. There are 3 types of soil erosion there. They are surface erosion, gully erosion and gravity erosion. The surface erosion forms mainly in sloping cultivated land, the gully erosion mainly in hills where the height above sea level is below 500 m, and the gravity erosion mainly in the area of rainstorm centers. The serious soil erosion has brought about kinds of harm. For example, the soil erosion destroyed cultivated land, with area reducing and fertility dropping decline; silted up reservoirs and rivers, reducing their benefits of storing water and shipping; reduced the rate of vegetation cover, leading to environment worsening and the flood and drought disasters occurring frequently. The primary causes of formation of soil erosion are as follows: the surface slope and precipitation are bigger, and the rainstorm are concentrated; over opening up wasteland, and there is too more sloping cultivated land; excessive felling forest and herding, causing more serious vegetation destruction, and making the lower rate of vegetation cover; the protective measurements of soil erosion are slack when mining and constructing roads. To deal with the above features and causes of formation of soil erosion, the aimed harnessing countermeasures about policy, laws, administration, economy and technology would be taken in the works of soil erosion harnessing.