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广东省清远市清城区杨桃树小流域,地处北回归线附近,属南亚热带季风气候,多年平均气温21℃,平均年降雨量2215毫米,24小时最大降雨量641毫米,无霜期320天。流域内北高南低,平均海拔高程326米。全流域有21个自然村,464户,2010人。土地总面积13.92平方公里,其中山地占80.8%,耕地占19.19%。1984年(治理前)有宜林荒地649亩,宜林荒山6274亩。 境内为丘陵低山地貌,山体由花岗岩组成。花岗岩含石英、云母、长石等矿物,因热胀冷缩的作用,加厚了表土的风化层,每逢暴雨,便导致严重的水土流失。
Qingcheng District of Qingyuan City, Guangdong Province, Yangsan small watershed, is located near the Tropic of Cancer, a subtropical monsoon climate, the average annual temperature of 21 ℃, the average annual rainfall of 2215 mm, 24-hour maximum rainfall of 641 mm, frost-free period of 320 days. High north to south basin, with an average elevation of 326 meters. The whole basin has 21 villages, 464 households, 2010 people. The total land area of 13.92 square kilometers, of which 80.8% of the mountains, 19.19% of arable land. In 1984 (before the management) there are 649 acres of suitable wasteland, 6274 acres of barren hills. In the hilly low mountain landscape, the mountain is composed of granite. Granite containing quartz, mica, feldspar and other minerals, due to the role of thermal expansion and contraction, thickened topsoil weathering layer, every heavy rain, it will lead to serious soil erosion.