甘肃省水土流失综合防治对策

The Soil Erosion and its Countermeasures in Gansu Province

甘肃是西部水土流失较严重的省份之一 ,全省有水土流失面积 37.94× 1 0 4 km2 ,占全省土地面积的 83.5 %。黄河流域主要是水力侵蚀 ,长江流域为重力侵蚀 ,河西内陆流域以风力侵蚀为主。水土流失形成的自然因素为地质结构破碎、土壤质地疏松、降雨时空变率大、植被覆盖度差 ,是缓变因素。而不合理的水土资源开发 ,滥伐毁草过牧和工程建设等人类活动则是叠加在自然变化上的突变因素 ,加剧了水土流失。未来结合西部大开发的良好机遇 ,主要采取以小流域为单元的综合治理、因地制宜的实施退耕还林还草策略。

Gansu Province is one of the region in the Western China where suffer the serious soil erosion. The area of the soil erosion is 37.94×10 4km 2, which accounts for about 83.5 percent of the total land in Gansu Province and it is becoming the major obstacle to the development of agriculture and economy. The types of soil erosion are hydraulic erosion, gravitational erosion and Aeolian erosion. Soil hydraulic erosion mainly occurs in the loess Plateau of Yellow river basin. Soil gravitational erosion is ubiquity in the Yangzi river basin of the southern Gansu. Soil Aeolian erosion mainly takes place in the inland basin of Hexi Corridor. Both the natural factors and Human activity have the influences on the soil erosion and combined to further the intensity and frequency. The former are consisted of geological, physiognomy, precipitation and vegetation. In the recent years, with the quickly population growth, unreasonable water and land development, excessive disafforestation and graze, and some new basic engineering construction increased rapidly and led to vegetation degradation and land desertification, which then aggravate the soil erosion. A lot of things have been done to father the soil erosion and the effect of soil and water conservation is obvious. However, more countermeasures should be take into action to prevention and control the soil erosion。