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山东省沂水县下位区的牛场子村,东、南、西三面环山,呈向北开口的簸箕形,自成一个小流域。这个小流域总面积292.4公顷,有山头14座,大沟13条。1979年以前,全村水土流失总面积233.4公顷,占全村山地总面积的80%,其中:剧烈流失面积为70公顷,占流失面积的30%;中度流失面积为133.4公顷,占57%;轻度流失面积为30公顷,占13%。每逢大雨,整个流域山洪翻腾,泥沙俱下。据计算,沙土流失每年平均在2万立方米以上。水土流失严重地破坏了生态平衡,造
Yishui County, Shandong Province, Niuchangzi village, East, South, West surrounded by mountains, was open to the north dustpan-shaped, since a small watershed. The total area of 292.4 hectares of small watershed, there are 14 hills, 13 ditches. Before 1979, the total area of soil and water loss in the village was 233.4 hectares, accounting for 80% of the total mountainous area of the village, of which: 70 hectares of violent loss, accounting for 30% of the lost area; moderate loss of 133.4 hectares, accounting for 57% ; Light loss area of 30 hectares, accounting for 13%. Every heavy rains, torrents flood torrents, sediment all. According to calculations, the loss of sand averages more than 20,000 cubic meters per year. Soil and water loss seriously damaged the ecological balance and made