小兴安岭森林采伐对河川径流的影响

采用大流域径流测定与小流域对比实验相结合的方法，利用35年的径流和森林资源变化资料，对小兴安岭林区森林采伐后河川径流发生的一系列变化进行了全面系统的研究.结果表明,森林采伐后营造落叶松人工林，造林初期10年内，河川径流量表现为增加趋势;随着落叶松人工林的不断生长和郁闭成林，采伐流域的径流量逐渐减少，并趋于采伐前水平或低于采伐前水平（与对照流域相比）.河川年径流量与年降水量、森林采伐面积及更新造林面积密切相关.森林采伐面积与年径流量呈正相关，森林采伐能增加河川年径流量;更新造林面积与年径流量呈负相关，更新造林能减少年径流量.而森林采伐对洪峰流量和融雪径流量均有显著增加作用.

Effects of forest harvesting on river runoff in Xiaoxing'anling

By the method of runoff determination in large basin combined with contrast experiment in small watershed,and based on the runoff and forest resources data in past 35 years,this paper studied the serial changes of river runoff in Xiaoxinganling after forest harvesting.The results showed that the river flow was increased in the early 10 years after forest harvesting,but decreased gradually with the growth and crown closure of artificial larch forest,tended towards or even lower than the level before harvesting.The river runoff had a close correlation with annual rainfall and the areas of forest harvesting and regeneration.Significant positive correlation was observed between annual flow and forest harvesting area,which resulted in the increase of river runoff after forest harvesting.Forest harvesting could also significantly increase the peak flood and snowmelt runoff.There was a negative correlation between regenerated forest area and annual flow,and thus,forest regeneration would decrease annual flow.