重庆四面山植被类型对坡面产流的影响

 为研究长江三峡库区植被类型对坡面产流的影响,在重庆四面山布设针阔混交林、阔叶林、楠竹林、灌丛和农耕地5种不同植被类型的标准径流小区。对天然降雨过程和由降雨产生的地表径流进行观测。结果表明:不同植被类型林地地表径流量的平均值,从大到小依次为农地、灌丛、楠竹林、阔叶林和针阔混交林,分别是6·45、4·12、2·91、2·34和1·57mm。3种以乔木为主的林地地表径流量,均小于农地的地表径流量,不同乔木林地地表径流量差异不显著。不同植被类型林地地表径流量与降雨量存在显著的相关关系,与降雨强度也存在极显著的相关关系,并且都表现为多项式或幂函数关系。在同一降雨条件下,不同植被类型林地(包括农地),地表径流变化趋势存在一定差异,且均是农地地表径流量最大。

Effect of the vegetation types on runoff generation on slope land in Simian Mountain of Chongqing

To study effect of vegetation types on runoff generation on slope land in the Three Gorges reservoir area of the Yangtze River, 5 kinds of standard runoff plot were laid out under different vegetation types in the Simian Mountain of Chongqing City. The vegetation types included mixed broadleaf-conifer forest, broad-leaved forest, Phyllostachys pubescens forest, shrub and agricultural cultivated land. Rainfall and surface runoff were measured on the plots. Results show that the grade of average values of surface runoff under different vegetation types was: agricultural cultivated land>shrub> Phyllostachys pubescens forest> broad-leaved forest> broadleaf-conifer forest. The values are 6.45mm, 4.12mm, 2.91mm, 2.34mm, 1.57mm. Surface runoff in selected arbor forestlands is smaller than that in agricultural cultivated land. Significant difference does not exist in surface runoff in different arbor forestlands. The correlation between rainfall amount and surface runoff in forestlands and agricultural cultivated land are notable, shown as polynomial function or power function. The correlation between rainfall intensity and surface runoff in forestlands and agricultural cultivated land are also notable, shown as polynomial function or power function. On the same rainfall condition, the variation tendencies of surface runoff in these types of forestland and agricultural cultivated land are different. And the amount of surface runoff in agricultural cultivated land is always the most.