植被缓冲带对地表径流阻控效果调查及模拟

为了定量分析和评价植被缓冲带对地表径流的阻控效果,对大沽河流域两岸典型植被进行了现场调查及取样,并利用VFSMOD模型初步探讨了植被缓冲带的作用。根据实地调查,获得了大沽河8个典型位置的缓冲带参数。结果表明:大沽河流域植被缓冲带主要由杨树、松树等高大乔木,罗布麻、碱蓬等灌木植物和结缕草、野艾蒿等草本植物组成; 这些植被对地表覆盖度较高,可有效地拦截泥沙、增加地表粗糙度,对地表径流具有良好的阻控效果。利用VFSMOD模型对北岔河村、仁兆镇拦河闸、程家小里村和后路家村4个缓冲带的地表径流阻控效果进行了模拟,结果表明:4处植被缓冲带分别可以拦截0.8,0.7,0.7,0.4 mm/min以下降雨强度产生的地表径流; 在植被缓冲带宽度和源区宽度同时变化的情况下,4处植被缓冲带宽度分别达到8,20,1,5 m时,对泥沙拦截率达到0.95以上。因此,大沽河两岸现存植被缓冲带可以对泥沙起到较好的阻控作用。

Investigation and Simulation on the Effect of Vegetative Filter Strip on Surface Runoff

In order to analyze and evaluate the effect of vegetation buffer zone on surface runoff quantitatively,field investigation and sampling of typical vegetation on both banks of Daguhe River Basin were carried out,and the function of vegetation buffer zone was discussed by using VFSMOD model.Based on the field investigations,the strip parameters of 8 typical locations in the Daguhe River were obtained.The results show that the vegetative filter strip in Daguhe River Basin is mainly composed of tall trees such as Populus L.and Pinus shrub.,plants such as Apocynum venetuml and Suaeda glauca Bunge,and herbaceous plants such as Zoysia japonica Steud and Artemisia argyi Levl.et Van;these plants have a high coverage on the surface of land,and can effectively intercept the sediment and increase the surface roughness,which has a good control effect on the surface runoff.The VFSMOD model is used to simulate the surface runoff control effect of four buffer zones which are located in Beichahe Village,Renzhao Town Barrage,Chengjiaxiaoli Village and Houlujia Village.The results show that the four vegetation buffer zones can intercept the surface runoff produced by rainfall intensities below 0.8,0.7,0.7 and 0.4 mm/min,respectively;when the width of the vegetation buffer zone and the width of the source area change at the same time,when the widths of the four vegetation buffer zones reach 8 m,20 m,1 m and 5 m respectively,the sediment interception rate reaches more than 0.95.Therefore,the existing vegetation buffer zones on both banks of Daguhe River can play the good role in retaining and controlling sediment.