欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

研究报告

Effect of plant roots on water characteristic curve parameters of artificial substrate based on HYDRUS-1D model

摘要：为了定量揭示绿色屋顶植物根系对人工基质水力特性的影响，选用两种景天属植物（垂盆草和佛甲草）及两种人工基质（珍珠岩和蛭石）进行水分及溶质运移实验，基于HYDRUS-1D模型反演人工基质水分特征曲线参数，以此分析植物根系所引起的人工基质水分特征曲线参数的变化.结果发现，植物根系使两种人工基质残余含水率θ_r降低、权重系数w增加.不同植物根系对两种人工基质饱和含水率θ_s的影响不同，体现为垂盆草根系相较佛甲草根系对θ_s的影响范围更小.植物根系对人工基质吸力参数α₁、α₂的改变效应随人工基质种类发生变化，表现为珍珠岩基质α₁、α₂均因垂盆草根系得以提高、因佛甲草根系而降低，蛭石基质α₁、α₂则因植物根系分别降低和增加.研究结果可为绿色屋顶植物-人工基质结构优化提供科学依据.

Abstract：In order to reveal the effect of plant roots on hydraulic properties of artificial substrate for green roofs， two types of sedum plants （Sedum sarmentosum Bunge and Sedum lineare Thunb， respectively） and two types of artificial substrates （perlite and vermiculite， respectively） were used for water and solute transport experiments. Water characteristic curve parameters of artificial substrate were calculated inversely by HYDRUS-1D model， and the root-induced changes of these parameters were analyzed. For both artificial substrates， the residual water content θ_r is decreased and the weight coefficient w is increased with the existence of plant roots. Different types of plant roots have different effects on the saturated water content θ_s. For both artificial substrates， the root-induced change in θ_s from Sedum sarmentosum Bunge is smaller than that from Sedum lineare Thunb. The effects of plant roots on the suction parameters α₁and α₂vary with the types of artificial substrates. For the perlite substrate， the values of both α₁and α₂ are increased with the roots of Sedum sarmentosum Bunge but are decreased with the roots of Sedum lineare Thunb. For the vermiculite substrate， while the value of α₁is decreased， the value of α₂isincreased due to the plant roots. These results can provide a scientific basis for the structural optimization of plant-artificial substrates for green roofs.

Key words：green roofs sedum plants artificial substrate water and solute transport HYDRUS-1D parameters inversion