基于水文和土壤侵蚀模型评估植被过滤带净化径流中氮磷的效果  

Assessment on retention efficiency of vegetative filter strips to nitrogen and phosphorus in surface runoff based on hydrology and soil erosion model

作　　者：邓娜[1] 李怀恩[2] 

机构地区：[1]湖南农业大学资源环境学院,长沙410128 [2]西安理工大学西北旱区生态水利工程国家重点实验室培育基地,西安710048

出　　处：《农业工程学报》2015年第18期155-161,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(51279158;51409101)

摘　　要：为了方便快速地评估单次径流条件下植被过滤带对污染物氮、磷的净化效果,该文设计了地表径流的模拟放水试验,分析了泥沙与颗粒态污染物的相关性,依据土壤混合层概念简化了土壤污染物的输移,建立了植被过滤带对污染物作用效果的估算模型。结果表明:径流中颗粒态氮、磷含量与泥沙含量有显著相关性(P<0.05),据此建立线性相关方程,估算出植被过滤带对颗粒态污染物的净化效果,其86%以上样本的颗粒态氮、磷质量浓度模拟偏差均在±20%之内;溶解态氮、磷的迁移分两部分,即发生于坡面地表径流中和土壤混合层中,分别根据质量平衡原理建立方程对溶解态污染物的迁移进行了模拟,验证得到83%以上样本的溶解态氮质量浓度模拟偏差在±20%之内,67%以上样本的溶解态磷质量浓度模拟偏差也在±20%之内,研究表明,可以基于土壤混合层概念和水文及土壤侵蚀模型对植被过滤带净化效果进行评估。Vegetative filter strips can effectively reduce nitrogen and phosphorus load or concentration from agricultural land to surface water. However, the efficiency of vegetative filter strips vary with soil, hydrology and vegetation condition in different rainfall-runoff cases through long-term monitoring, so it is important to assess retention efficiency of vegetative filter strips under single rainfall-runoff condition. Mathematical model is an important tool for the planning and design of vegetative filter strips. Thus, an ease-to-use assessment model is presented to better assess nitrogen and phosphorus retention effect by vegetative filter strips under single runoff condition in the northwest area of China with serious soil erosion. The simplified model proposed involves 3 parts： coupling sub-model, linear correlation sub-model and mixing zone conceptual sub-model. The coupling sub-model of the vegetative filter strips model （VFSMOD） and the modified universal soil loss equation （MUSLE） is made to simulate purification effect of suspended solids （mainly means sediments）, because sediment retention efficiency is the combined effect of the sediments entrapped process and the soil erosion or sediments yield process in vegetative filter strips itself. According to significant correlation with sediments and those particle pollutants on runoff, the linear correlation method is used to calculate removal effect of particle nitrogen and particle phosphorus by vegetative filter strips. Infiltration is regarded as the only mechanism to remove dissolved pollutants, namely vegetative filter strips reduce dissolved nitrogen and phosphorus volume by diffusion and infiltration into soil. Therefore, based on mechanism research of the interaction of dissolved pollutants in topsoil and surface runoff, and through simplifying pollutant transport in deep soil, the mixing zone conceptual sub-model is utilized to assess the effect of vegetative filter strips on dissolved nitrogen and phosphorus. Furthermore, the mass dyna

关 键 词：土壤 氮 磷 植被过滤带 净化效果 评估 

分 类 号：X171.1[环境科学与工程—环境科学]