基于VFSMOD模型的不同情景下河流生态缓冲带的截留效果模拟

采用植被缓冲带模型(VFSMOD)对不同情景下河流生态缓冲带(简称“缓冲带”)的截留效果进行了模拟，考察了土壤可蚀性、土壤质地、坡度、径流源区长度、缓冲带宽度等对缓冲带拦截效果的影响。结果表明： 随着土壤可蚀性因子(K因子)变大，土壤可蚀性增强，缓冲带泥沙输入量变大；坡度变大，拦截效率下降，在坡度分别为1%、3.5%、9%和30%的条件下，达到60%的径流截留效率(RIR)，缓冲带的宽度分别需要43.9，50.6，52.9和68.8 m；当RIR达到60%，砂质黏壤土、粉质黏壤土、壤土和黏土所需缓冲带的宽度为109.2、114.6、50.6、128.7 m；径流源区长度越长，缓冲带拦截效率越低。上述模拟结果可为缓冲带的设计提供参考。

VFSMOD model-based simulation of interception by ecological buffer zone under different scenarios

Non-point source pollution has become an important water pollution source all over the world because of its complex process and wide range of influence. As one of the best management measures (BMPs) for non-point source pollution, ecological buffer zone (EBZ) has become a widely acknowledged solution. In this paper, the VFSMOD model was used to evaluate the effect of ecological buffer zone under different scenarios. The influence of soil erodibility, soil texture, slope, length of runoff source area and width of buffer zone on the interception effect of ecological buffer zone was investigated. The results showed that the soil erodibility increased with the K factor, causing the increase of the silt input into the buffer zone. The greater the gradient, the lower the interception efficiency was. With the gradient of 1%, 3.5%, 9% and 30%, the width of EBZ was 43.9, 50.6, 52.9 and 68.8 m, respectively, for reaching RIR of 60%. At the same RIR, the width of EBZ was 109.2 m for sandy clay loam, 114.6 m for silty clay loam, 50.6 m for loam and 128.7 m for clay. The longer the length of runoff source area, the lower the interception efficiency of buffer zone was. The simulation results could provide reference for the design of ecological buffer zone.