汇/分流截-排水方式对降低三峡库区坡地磷流失量的影响  

Confluence/diversion catch-drainage layout measures decreasing phosphorus loss from sloping lands in Three Gorges Reservoir Areas

作　　者：李永灏 龚俐婕 王卓 黄欢[1] 宋兰 李天阳[1] 何丙辉[1] LI Yonghao;GONG Lijie;WANG Zhuo;HUANG Huan;SONG Lan;LI Tianyang;HE Binghui(College of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院,重庆400715

出　　处：《农业工程学报》2023年第22期94-103,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：重庆市技术创新与应用发展专项面上项目(CSTB2022TIAD-GPX0043);水利部重大科技项目(SKS-2022078);重庆市自然科学基金项目(CSTB2022NSCQ-MSX0385);中央高校基本科研业务费专项(SWU-KT22060)。

摘　　要：优化坡面截-排水方式能有效调控坡面养分流失,对防控农业面源污染和保障下游水环境安全具有重要意义。该研究旨在探明坡面截-排水方式的阻磷效应,通过采集3种土地利用类型(坡耕地、荒草地、有林地)典型坡面土样,在106 mm/h雨强下展开室内暴雨模拟试验,分析3种截-排水方式(汇流排水T1、分流排水T2、无措施CK)对坡面磷流失的影响。结果表明,不同土地利用类型下,与CK相比,T1和T2平均径流率分别减小40.33%~44.33%、42.57%~54.52%,平均产沙率分别减少68.14%~71.15%、60.55%~72.57%。各截-排水方式下,有林地的平均产沙率显著低于荒草地和坡耕地。各土地利用类型下,全磷(total phosphorus,TP)、可溶性磷(dissolved phosphorus,DP)及颗粒态磷(particulate phosphorus,PP)的变化范围和平均浓度均表现为T1<T2<CK。与CK相比,T1、T2能显著减小TP、DP、PP的流失量(P<0.05)。坡耕地下,TP、DP、PP流失量平均降低幅度为T2(70.34%)>T1(66.47%),而荒草地和有林地条件下,TP、DP、PP流失量平均降低幅度为T1(65.19%)>T2(59.16%)。研究表明,汇流和分流2种截-排水方式均能有效降低坡面磷素流失量,其中汇流方式可能更适用于荒草地和林地水系,而分流方式更适用于坡耕地水系。Catch-drainage layout measures have been widely applied as a benefitial soil and water conservation measure on the sloping land.However,little information is availiable on the effect of catch-drainage measures on soil phosphorus loss on the sloping lands.Optimizing the catch-drainage layout measure can effectively control the nutrient loss on the sloping lands,which is of great significance for preventing and controlling agricultural non-point source pollution and ensuring the safety of downstream water environment.Soil samples were collected from typical sloping lands of three land use types(slope farmland,grassland and forest land)for simulated rainfall with an rainfall intensity of 106 mm/h to study the effects of three catch-drainage layout measures on phosphorus loss on sloping land.The PVC plastic plate was inserted into the soil to form three catch-drainage layouts,including T1-Confluence,T2-Divergence,CK-Control check.Runoff and sediment samples were collected during the artificial simulated rainfall to determine the concentration of total phosphorus,dissolved phosphorus and particulate phosphorus.The results showed that T1 and T2 decreased the average runoff rates by 40.33%-44.33%and 42.57%-54.52%and the average sediment yield rates by 68.14%-71.15%and 60.55%-72.57%at each land use type compared with CK,repsectively.It was because that T1 and T2 showed segmented retention effects on runoff,which promoted water infiltration,reduced runoff velocity,and effectively weaken the scouring effect and sediment carrying capacity of runoff,resulting in a decrease in runoff volume and sediment yield.Under each catch-drainage layout measure,the average sediment yield rate under forest land was significantly lower than that under grassland and slope farmland.The variation range and average concentration of total phosphorus,dissolved phosphorus and particulate phosphorus under different land use types showed T1<T2<CK.Dissolved phosphorus was the main form of phosphorus loss in this study,which was different from previo

关 键 词：坡面 磷 土地利用 截-排水方式 面源污染 

分 类 号：S276[农业科学—农业水土工程]