重庆缙云山不同土地利用类型坡面产流对暴雨的响应

 为给三峡库区理水调洪型植被建设提供一定依据,在三峡库区重庆缙云山5种典型土地利用类型(混交林,阔叶林,楠竹林,灌木林及农地)建立坡面径流小区,从产流量、产流历时和产流过程来研究坡面产流对暴雨的响应。结果表明:在相同暴雨条件下,楠竹林地表径流深分别为混交林的2．7倍,为灌木林的3．7倍,为农地的4．5倍,为阔叶林的5．7倍。混交林和阔叶林的地下径流深比其他土地利用类型大一个数量级,为其他土地利用类型的 8-10倍。混交林坡面径流产流历时可延长248min,农地最少,仅为33 min。混交林地下产流历时可延长59 h;阔叶林居次,为50 h;农地产流历时缩短近11h。楠竹林坡面径流峰值约为混交林和灌木林的2倍,为阔叶林和农地的3倍。阔叶林和混交林地下径流峰值比楠竹林大2个数量级,比灌木林和农地大1个数量级。因此,重庆缙云山各土地利用类型中,混交林和阔叶林理水调洪功能最强,楠竹林理水调洪功能最差。

Responses of slope runoff generation to rainstorm with different land use types in Jinyun mountain in Chongqing city

To provide basis for vegetation construction of water control and flood regulating in Three Gorges Reservior Area, response of runoff generation amount, runoff duration and runoff generation process to rainstorm was studied based on the slope runoff plots of 5 typical land use types ( mixed forest, broadleaf forest, bamboo forest, shrub forest and framland) in Jinyun mountainous region in Chongqing city, Three Gorges Reservoir Area. The results show that, in the same rainstorm condition, the surface runoff depth of bamboo forest is as 2.7 times as that of mixed forest, as 3.7 times as that of shrubs, as 4.5 times as that of farmland, and as 5.7 times as that of broadleaf forest, and the order of magnitude of underground runoff depth of mixed forest and broadleaf is greater than other land use types, and the depth is 8-10 times as deep as that of other land use types. The longest extended duration of the slope runoff generation is 248 min in the mixed forest, and the shortest is 33 min in farmland. And the longest xtented duration of the underground runoff generation is 59 h in the mixed forest, 50 h in the broadleaf forest, and the shortest is about 11 h in farmland. The peak value of surface runoff is about twice as much as that of mixed forest and shrubs, and is about 3 times as much as that of broadleaf forest and farmland. And the peak value of underground runoff generation is two grade greater than that of bamboo forest, and one greater than that of shrub forest and farmland. Therefore, the mixed forest and broadleaf forest has the greatest function of water control and flood regulation, and the func- tion of the bamboo forest is the worst.