砒砂岩区沙棘林生态工程减洪减沙作用分析

 通过"水保法"计算沙棘林在砒砂岩区的减洪减沙效益,分析晋陕蒙砒砂岩区沙棘林生态工程的减洪减沙量,以及对研究区直接入黄支流的减洪减沙作用。结果显示:研究区流域内沙棘林占流域内总林地面积的比例逐年增大,沙棘林的减洪减沙量也逐年增大,从2002年到2008年,皇甫川、孤山川、窟野河等三支流沙棘林平均每年总减洪量480.84万m3,总减沙量302.65万t。研究结果对砒砂岩区配置水土保持措施有重要的参考价值。

Reduction effects of flood and sediment yield of Hippophae rhamnoides Linn forest in soft sandstone area

Hippophae rhamnoides Linn afforestation has been used as a major water and soil conservation measure in soft sandstone area from experiment on spot to promotion in large scale more than 40 years.The project of Hippophae rhamnoides Linn afforestation in Shanxi,Shaanxi and Inner Mongolia soft sandstone area that has been implemented since 1998,has made sea buckthorn afforestation area increased to a new level.Through the implementation of the project,the environment and vegetation cover have been greatly improved;soil erosion amount reduces year by year.In order to evaluate the reduction effects of flood and sediment yield by Hippophae rhamnoides Linn forest.Based on soil conservation method,the effects of flood and sediment yield reduction were calculated,and the role of sediment reduction to the tributaries that directly flow into the Yellow River was analyzed.The result showed that the area proportion of sea buckthorn forest accounts for the total forest in the watershed of the project area increased year by year,flood and sediment yield reduction has also increased yearly.In the years 2002—2008,the average annual total flood and sediment yield reduction of Huangpu river,Gushan river,Kuye river,that reduced by Hippophae rhamnoides Linn forest is 4 808 400 m3and 3 026 500 t respectively.The results has an important role in guiding the configuration of soil and water conservation measures in soft sandstone area.