不同生长阶段佛甲草根系对蛭石基质水力特性及水分运移的影响  

Effects of Sedum lineare Thunb roots at different growth stages on hydraulic properties and water flow migration of vermiculite substrate

作　　者：陈雨 刘瑞芬 刘德富 CHEN Yu;LIU Rui-fen;LIU De-fu(Key Laboratory of Health Intelligent Perception and Ecological Restoration of River and Lake,Ministry of Education,Hubei Key Laboratory of Ecological Remediation of River-lakes and Algae Utilization,Department of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,湖北工业大学河湖健康智慧感知与生态修复教育部重点实验室,河湖生态修复与藻类利用湖北省重点实验室,湖北武汉430068

出　　处：《中国环境科学》2023年第12期6393-6405,共13页China Environmental Science

基　　金：国家自然科学基金青年科学基金项目(51909081)。

摘　　要：为了定量揭示绿色屋顶景天属植物根系不同生长阶段对人工基质水力特性及水分运移的影响,将佛甲草培养于14cm厚的蛭石基质中,培养至30,60和90d后,进行根系特征测定及根系根长频率分布函数评价;并基于根系根长频率分布函数和蒸渗试验数据预测含植物根系的蛭石基质水力特性,以此分析根系生长对水力特性的影响;最后采用HYDRUS-1D模拟分析武汉市典型丰水年降雨条件下佛甲草—蛭石基质水分运移规律.结果发现,三种根系根长频率分布函数中,由对数正态分布函数所预测的佛甲草根系表面积和根系体积误差均小于20%,适用于佛甲草根系特征的量化.含植物根系蛭石基质水力特性参数θr、n1、w和Ks相较于不含植物根系情形均增加、α2和n2均减少;在根系生长阶段θr一直增大、θs、α2和w一直减小.当考虑佛甲草根系四季(春、夏、秋、冬)生长状态时,含植物根系蛭石基质蒸发量相较于不含植物根系情形分别减少4.46%、2.94%、8.91%和7.56%,截流率分别减少1.64%、1.22%、7.10%和7.06%.The study aims to reveal the effect of sedum plant roots at different growth stages on hydraulic properties and water flow migration of artificial substrate for green roofs.Sedum lineare Thunb was cultured in the 14cm-depth vermiculite substrate,and thereafter,plant root characteristics were measured and root length frequency distribution functions were evaluated at 30d,60d and 90d.Based on root length frequency distribution functions and obtained lysimeter data,hydraulic characteristics of vermiculite substrate containing plant roots were predicted,and the effect of root growth on substrate hydraulic characteristics were analyzed.Finally,water flow migration of Sedum lineare Thunb-Vermiculite substrate under the rainfall condition of a typical hydrological year in Wuhan was simulated by HYDRUS-1D model.The results showed that among three root length frequency distribution functions,errors of predicted root surface area and root volume from the lognormal distribution function were both less than 20%,indicating the function was suitable for the sedum root quantification.The results also showed that the hydraulic characteristic parametersθr、n1、w and Ks of vermiculite containing plant roots were increased,whileα2 and n2 were reduced,when compared with parameters from vermiculite without plant roots.During the whole plant root growth stage,θr increased continuously butθs,α2 and w decreased continuously.Compared with data from the simulation scenario of vermiculite without plant roots,evapotranspiration of vermiculite substrate with Sedum lineare Thunb roots from four seasons(spring,summer,autumn and winter)were reduced by 4.46%,2.94%,8.91%and 7.56%respectively,and rainfall volume reduction rates were also reduced by 1.64%,1.22%,7.10%and 7.06%respectively.

关 键 词：绿色屋顶 植物生长 根系分布函数 水力特性 水分运移 影响因素 

分 类 号：X522[环境科学与工程—环境工程]