论文部分内容阅读
三川河位于吕梁山脉中部,黄河北干流左岸,属黄河一级支流。流域总面积4161平方公里,包括吕梁地区方山、离石、中阳、柳林四县的47个乡镇,834个村,共有41.82万人,其中农业人口35.49万人。治理前,全流域有水土流失面积2767.2平方公里,占流域面积的66.5％,年均土壤流失量2908万吨,平均年侵蚀模数7024t/km~2,其中黄土丘陵区高达1.56万t/km~2。水土流失面广量大,是构成这一地区长期多灾、低产、贫困的主要原因。解放30多年,这里的水土保持工作取得了一定成效,但由于多种原因,恶劣的自然条件并没有得到明显的改观,粮食亩
Sanchuan River is located in central Lvliang Mountains, the left bank of the Yellow River north, a tributary of the Yellow River. The total basin area of 4161 square kilometers, including Luliang Fangshan, Lishi, Zhongyang, Liulin four counties 47 towns and 834 villages, a total of 418,200 people, of which agricultural population of 354,900. Before the treatment, the whole basin has an area of 2767.2 square kilometers of soil erosion, accounting for 66.5% of the basin area, with an average annual soil loss of 29.08 million tons and an average annual erosion modulus of 7024t / km ~ 2, of which, the loess hilly region reaches up to 15600 t / km ~ 2. The large amount of soil and water loss is the main cause of long-term disaster-stricken, low-yielding and poor areas in this area. After more than 30 years of liberation, some achievements have been made in water and soil conservation work here. However, due to various reasons, the bad natural conditions have not been significantly changed. The grain acreage of mu