论文部分内容阅读
豫南大别山区的固始、商城、新县、潢川、光山、罗山、信阳共有山丘区面积一万余平方公里,250余万人。年平均降雨量1400～1100毫米,年平均气温15.2℃,无霜期217～229天,地表岩石出露以粗粒花岗岩、片麻岩为主,土层一般厚度20～50厘米。土壤以黄棕壤、水稻土为主,山高坡陡,源短流急,主峰在商城县境金刚台,高程为584米。 本区水土流失的特点以面蚀为主,局部有沟蚀和泥石流的现象发生。区域内土层薄,地表多为粗粒花岗岩片麻岩,土壤流失推移质多,悬移质少,河床沟道淤积严重,造成河沟高于田,落河田增多,一遇暴雨则洪水漫溢,农田被水打沙压,受害农田多年平均达25.4万亩,部分农田堆沙无法清除,使沙砾化面积达11万亩。
South of the Dabie Mountains in southern Gushi, shopping malls, New County, Huangchuan, Guangshan, Luoshan, Xinyang total area of ?? 10,000 square kilometers, more than 250 million people. The average annual rainfall of 1400 ~ 1100 mm, the annual average temperature of 15.2 ℃, frost-free period of 217 to 229 days, surface rocks exposed to coarse-grained granite, gneiss, the general thickness of 20 to 50 cm. Yellow-brown soil soil, paddy soil-based, steep mountain slope, the source short stream acute, the main peak in Shangcheng County Jingangtai, elevation of 584 meters. The characteristics of soil erosion in this area are mainly surface erosion, and local phenomena of gully erosion and debris flow occur. The soil in the area is thin and the surface is mostly coarse-grained granite gneiss. The drainage of soil is more and more, the amount of suspended sediment is less and the sedimentation of river channel is serious, resulting in the increase of river-valley above the field and falling river, The farmland was hit by water. The average number of affected farmland was 254,000 mu for many years. Part of the farmland was not able to clear the sand and the gravel area reached 110,000 mu.