植物根系对绿色屋顶径流调控功能影响  

Effects of plant roots on the regulating function of green roof runoff

作　　者：王任重远 张守红[1,2,3] 章孙逊 闫婧 杨航 王恺 张成玉 魏良怡 Wang-Ren Zhongyuan;Zhang Shouhong;Zhang Sunxun;Yan Jing;Yang Hang;Wang Kai;Zhang Chengyu;Wei Liangyi(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Beijing Engineering Research Center of Soil and Water Conservation,Beijing 100083,China;National Station for Forest Ecosystem Research in Jixian County,Jixian 042200,Shanxi,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京市水土保持工程技术研究中心,北京100083 [3]山西吉县森林生态系统国家野外科学观测研究站,山西吉县042200

出　　处：《北京林业大学学报》2023年第6期108-116,共9页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(51609004);水体污染控制与治理(2017ZX07102)。

摘　　要：【目的】绿色屋顶具有滞留雨水、削减和延缓洪峰等径流调控功能,但植物根系对其径流调控功能的影响尚不清楚。本研究旨在揭示植物根系对绿色屋顶径流调控功能的影响,为绿色屋顶植物配置和管理提供科学支撑。【方法】基于在北京城区搭建的3种不同根系特征植物(佛甲草、大花马齿苋、八宝景天)和无植被覆盖(对照)绿色屋顶的降雨产流和基质含水量动态变化监测,测定植物根长密度和根径等根系特征,定量分析植物根系对绿色屋顶径流调控功能的影响。【结果】含根系绿色屋顶基质的平均雨水滞蓄量比对照绿色屋顶高2.1~4.1 mm,但平均产流时间较对照绿色屋顶提前6~10 min,平均峰现时间提前9~26 min。在总根长密度相近的情况下,根茎较粗的八宝景天绿色屋顶的径流调控功能优于根茎较细的大花马齿苋绿色屋顶。佛甲草绿色屋顶的总根长密度和平均根径最大,其雨水初损占比最低,最易产流,且随着降雨量的增大,其径流调控效益相对其他两种植物的绿色屋顶下降更明显。【结论】植物根系可提高绿色屋顶基质的滞蓄能力,但会导致绿色屋顶产流提前;同时根系的径级分布也会影响绿色屋顶的径流调控功能。[Objective]Green roofs have various functions of stormwater management(e.g.,rainwater retention,peak discharge reduction).However,the effects of plant roots on the hydrological performance of green roofs are unclear.The objective of this study was to indicate the impact of plant roots on hydrological performance of green roofs.The results of this study were expected to provide scientific support for green roof plant configuration and management.[Method]Four green roofs with different vegetation cover(Sedum lineare,Portulaca grandiflora,Sedum spectabile and a non-vegetated substrate)were set up in Beijing,and the rainfall-runoff process and water content dynamic changes of green roofs were monitored.The root characteristics such as root length density and root diameter of plants were measured and the influence of plant roots on the stormwater retention of green roofs was analyzed.[Result]The stormwater retention capacity of green roof substrate with plant roots was 2.1−4.1 mm larger than that of the nonvegetated substrate.The average time of runoff generation from green roofs containing plant roots was 6−10 min earlier than the non-vegetated substrate,and the average peak present time was 9−26 min earlier than the non-vegetated substrate.When the total root length density was similar,the stormwater retention performance of the S.spectabile green roof with thick root system was better than that of the P.grandiflora with thin root system.The S.lineare had the largest total root length density and average root diameter among the other plants,and the S.lineare green roof had the least amount of the proportion of the initial loss.So as the rainfall increased,it may have a more obvious decline of stormwater retention performance than the other plants.[Conclusion]Although the plant roots could increase the stormwater retention capacity of green roofs,it may advance the generation time of runoff.Meanwhile,the radial distribution of the root system also affects the runoff regulation function of green roofs.

关 键 词：绿色屋顶 根系特征 基质 雨水滞蓄能力 径流调控 

分 类 号：S731[农业科学—林学]