植被格局特征对大理河流域侵蚀产沙的响应

发布时间：2018-10-25 06:41

【摘要】：为了进一步研究植被覆盖FBM(fractional brownian motion)分形维数在不同流域中对植被覆盖特征的综合效果及作为固定参数代替现有的植被量化指标在实际的水文、土壤侵蚀等预测模型中的应用,该文通过对大理河流域上中下游青阳岔、李家河和曹坪3个水文站控制流域的降雨、径流和产沙等资料的全面综合分析,以次降雨径流侵蚀功率作为侵蚀外营力输入,通过对站控流域地貌特征FBM分形维数、植被景观格局FBM分形维数和NDVI植被指数作为描述下垫面特征,以地理信息系统(GIS)为平台,利用GIS和RS技术,构建大理河流域侵蚀产沙量多元线性回归模型,并通过2组不同参数预测结果对比,结果表明:以植被格局分形维数为植被量化参数的模型输沙模数模拟值与实测值之间的相对误差和绝对误差比以NDVI为植被量化参数的小;在38场次暴雨洪水中,基于植被格局分形维数为植被量化参数的模型次暴雨输沙模数模拟值与实测值之间的相对误差小于10%、20%、50%的分别占总场次的34.21%、55.26%、86.85%;38场次暴雨输沙模数的模拟值和实测值之间的平均相对误差为25.19%,其中模拟值与实测值绝对误差小于300 t/km~2有31场,植被格局FBM分形维数可以更好反映植被覆盖与水土流失之间的关系,并且分析得到植被格局分形维数与土壤侵蚀强度之间呈负相关关系,决定系数为0.506 6,即土壤侵蚀强度随着植被格局FBM分析维数的增大呈减小趋势,说明植被格局FBM分形维数对土壤侵蚀强度的影响较大。
[Abstract]:In order to further study the comprehensive effect of FBM (fractional brownian motion) fractal dimension of vegetation cover on vegetation cover characteristics in different watersheds and its application as a fixed parameter to replace the existing quantitative vegetation indexes in actual hydrological and soil erosion prediction models. Based on the comprehensive analysis of the rainfall, runoff and sediment yield data of the three hydrologic stations in the upper and lower reaches of the Dali River Basin, Qingyangcha, Lijiahe and Chaoping, the erosion power of secondary rainfall runoff is used as the input of external erosion force. The FBM fractal dimension, FBM fractal dimension of vegetation landscape pattern and NDVI vegetation index were used to describe the underlying surface characteristics of the station controlled watershed, and the GIS and RS techniques were used to describe the underlying surface features on the platform of (GIS). The multivariate linear regression model of erosion and sediment yield in Dali River Basin was constructed, and the results of two groups of different parameters were compared. The results show that the relative error and absolute error between the simulated value of sediment transport modulus and the measured value are smaller than those of NDVI as the quantitative parameters of vegetation, and in 38 times of rainstorm flood, the relative error and absolute error of the model with fractal dimension of vegetation pattern as the quantitative parameter of vegetation are smaller than that of the measured value. Model based on Fractal Dimension of vegetation pattern the relative error between simulated value and measured value of sediment transport modulus of secondary rainstorm is less than 10 / 20 / 50% in 34.21 / 55.26 / 86.8585 / 38 rainstorm sediment transport modulus respectively and the measured value is lower than 10 / 20 / 50%. The average relative error between them is 25.19, in which the absolute error between the simulated value and the measured value is less than 300 t/km~2, and there are 31 fields. FBM fractal dimension of vegetation pattern can better reflect the relationship between vegetation cover and soil erosion, and the correlation between fractal dimension of vegetation pattern and soil erosion intensity is negative correlation. The coefficient of determination is 0.506, that is, soil erosion intensity decreases with the increase of FBM analysis dimension of vegetation pattern, indicating that FBM fractal dimension of vegetation pattern has a great influence on soil erosion intensity.
【作者单位】：北京市水科学技术研究院;北京林业大学水土保持学院;西安理工大学西北水资源与环境生态教育部重点实验室;北京市非常规水资源开发利用与节水工程技术研究中心;
【基金】：科技部项目京津冀耗水管理与资源节水技术研发示范(2016YFC0401403) 北京市科技计划项目都市农业用水监测评价和管理平台研究与示范(D151100004115004) 国家自然科学基金“黄土高原生态建设的生态-水文过程响应机理研究”(41330858);国家自然科学基金“基于能量过程的坡沟系统侵蚀产沙过程调控与模拟”(41471226) 北京市博士后工作经费资助项目
【分类号】：S157

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