砂壤土下滴灌毛白杨幼林土壤水分运移规律与模拟  

Patterns of Soil Water Movement in Drip-Irrigated Young Populus tomentosa Plantations on Sandy Loam Soil and Their Simulation

作　　者：李豆豆 席本野[1] 唐连峰 冯超 贺曰林 张亚雄[1] 刘龙龙[1] 刘金强[1] 贾黎明[1] Li Doudou;Xi Benye;Tang Lianfeng;Feng Chao;He Yuelin;Zhang Yaxiong;Liu Longlong;Liu Jinqiang;Jia Liming(Key Laboratory of Silviculture and Conservation of Ministry of Education,Beijing Forestry University,Beijing 100083;State-Owned Jiucheng Forest Farm in Gaotang County,Liaocheng 252872;Hunan Provincial Institute of Agriculture,Forestry and Industry Inventory and Planning,Changsha 410007)

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083 [2]高唐县国有旧城林场,聊城252872 [3]湖南省农林工业勘察设计研究总院,长沙410007

出　　处：《林业科学》2018年第12期157-168,共12页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(31400532; 31670625);"十二五"国家科技支撑计划资助(2015BAD09B02);国家重点研发计划课题(2016YFD0600403)

摘　　要：【目的】明确滴灌下林地土壤水分运移规律,以期为林分精准滴灌策略制定提供数据支撑和理论依据。【方法】以砂壤土下进行地表滴灌的2年生毛白杨人工林为研究对象,通过田间试验研究灌水及水分再分布过程中土壤水势(ψ_s)、湿润锋和含水率(θ)的动态变化规律,然后利用田间实测数据评估HYDRUS-2D/3D模拟土壤水分短期运动的精度和可行性,并运用验证后的模型对不同初始土壤含水率(θ_i)下的湿润锋运移进行模拟。【结果】灌溉过程中ψ_s、湿润锋水平和垂直运移距离、土壤湿润体内θ随灌水时长的变化可分别用Logistic函数(R^2=0.99)、对数(R^2=0.99)、幂函数(R^2=0.82)和多项式(R^2=0.99)函数描述;停灌时,湿润锋水平和垂直运移距离分别达到22.9和37.3 cm,湿润体内ψ_s和θ较灌溉开始时分别提高61.6%和30.9%,ψ_s在停灌后约120 h恢复至灌溉起始水平;湿润锋水平和垂直运移距离模拟值与实测值的平均偏差分别为1.3和4.5 cm,停灌时及水分再分布过程中HYDRUS-2D/3D模拟θ的平均RMSE和RMAE分别为0.021 cm^3·cm^(-3)和9.7%;利用HYDRUS-2D/3D模拟,得到试验地不同干旱程度时(土壤水分有效性的40%,60%,73%和80%)θ_i越高,湿润锋的水平和垂直运移均越大,且不同θ_i下的水平运移均略小于其垂直运移。【结论】HYDRUS-2D/3D可用于模拟砂壤土下地表滴灌毛白杨幼林的短期土壤水分动态。不同θ_i下湿润锋水平和垂直运移距离随灌溉时长的变化图,可为砂壤土上毛白杨及相似树种人工林的合理滴灌时长的确定提供参考。【Objective】Understanding the patterns of soil water movement under drip irrigation can provide supporting data and theoretical basis for developing precise drip irrigation strategies.【Method】A two-year-old Populus tomentosa plantation under surface drip irrigation on sandy loam soil was selected to measure the dynamics of soil water potential(ψs),wetting front and soil water content(θ)during irrigation and water redistribution periods.Then,the observed data in the field were used to evaluate the accuracy and feasibility of the HYDRUS-2D/3D model for simulating the short-term soil water movement.Besides,the validated model was used to simulate the dynamics of wetting front under different initial soil water content(θi).【Result】During irrigation,the variation ofψs,horizontal and vertical movement distances of the wetting front,andθwithin the wetting volume with irrigation duration can be described by the logistic function(R^2=0.99),the logarithm function(R^2=0.99),the power function(R^2=0.82),and the polynomial function(R^2=0.99),respectively.At the end of irrigation,the horizontal and vertical movement distances of the wetting front reached22.9and37.3cm,respectively.Theψs andθwithin the soil wetting volume were61.6%and30.9%higher than those at the start of the irrigation,respectively,but theψs decreased to its initial level about120hours after the stop of irrigation.The average deviations of the horizontal and vertical wetting radius between the simulated and measured values were1.3and4.5cm,respectively.The mean RMSE and RMAE of HYDRUS-2D/3D for simulatingθat the end of irrigation and during water redistribution were0.021cm^3·cm^-3and9.7%,respectively.The movement distances of wetting front in the experimental plantation under various soil drought degrees(soil water availabilities were40%,60%,73%,and80%)were obtained through scenarios simulations using HYDRUS-2D/3D.And it was found that the wetting front moved further under higherθi,and the movement distance of the wetting front was always s

关 键 词：毛白杨 滴灌 土壤水分运移 HYDRUS 湿润锋 土壤水势 土壤含水率 土壤湿润体 

分 类 号：S714.5[农业科学—林学] S715.3