黄土高原沟壑区典型造林树种蒸散发对气候变化的响应  

Response of evaporation and transpiration of typical afforestation tree species to climate changes in gully region of Loess Plateau

作　　者：李蓝君 宋孝玉[1] 夏露[1] 符娜[1] 李怀有[2] 李垚林[2] 冯丹 Li Lanjun;Song Xiaoyu;Xia Lu;Fu Na;Li Huaiyou;Li Yaolin;Feng Dan(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China(Xi’an University of Technology),Xi’an 710048,China;Xifeng Experiment Station of Soil and Water Conservation,Yellow River Conservancy Committee,Qingyang 745000,China;Lantian Water Conservancy and Soil and Water Conservation Workstation,Xi’an 710500,China)

机构地区：[1]省部共建西北旱区生态水利国家重点实验室(西安理工大学),西安710048 [2]黄委会西峰水土保持科学试验站,庆阳745000 [3]蓝田县水利水保工作站,西安710500

出　　处：《农业工程学报》2018年第20期148-159,共12页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(41771259;41171034);陕西省教育厅省级重点实验室科研计划项目(14JS059);陕西省水利科技计划项目(2016slkj-11)

摘　　要：为研究黄土沟壑区典型造林树种蒸散发对气候变化的响应,基于黄土沟壑区小流域刺槐、侧柏、油松样地实测蒸散发数据,借助Hydrus-1D软件构建了黄土沟壑区刺槐、侧柏及油松植被蒸腾与土壤蒸发的模拟模型,使用修正Morris法对模型参数敏感性进行分析,结果表明:>40～100 cm土壤孔径分布参数(n2),>40～100 cm土壤饱和体积含水率(θs2),0 cm土壤田间持水率(θf),根系吸水最适水势上阈值(h1),根系吸水最适土壤水势下阈值(h2),植物出现永久凋萎时的土壤水势(h3),消光系数(μ),截留模型经验参数(a)等参数对植被蒸腾影响较大,植被生理特征相关参数h1,h2,h3,μ,a的不同是造成树种间蒸腾量出现差异性的重要原因。选取2015年试验观测数据对模型进行率定,2016年试验观测数据对模型进行验证,土壤含水率及土壤蒸发的Nash-suttcliffe模拟效率系数(Ens)均在0.700以上。采用率定后的模型对预设情景下的蒸散发量进行模拟,结果表明:未来及不同水文年气候特征对刺槐蒸腾的影响程度大于蒸发,对侧柏和油松而言,则正好相反。所有气候情景下,刺槐、侧柏、油松的蒸腾量分布在128.8～282.6、99.3～200.3和140.5～220.5 mm,蒸发量分布在94.6～135.4、116.5～187.3和123.8～212.5 mm,蒸腾量与蒸发量均表现为丰水年>平水年>枯水年。3个树种蒸腾量对未来及不同水文年气候特征的响应程度表现为:刺槐>侧柏>油松,并且,同一时期内,在丰水年及平水年,刺槐蒸腾量最大,在枯水年,油松蒸腾量最大。3树种蒸发量对未来及不同水文年气候特征的响应程度表现为:油松>侧柏>刺槐。生长季降雨量对于同期蒸腾量与蒸发量的影响明显强于温度的影响,其与蒸腾量、蒸发量之间均呈极显著(P<0.01)线性关系。The Loess Plateau is the main rain-fed agricultural area in western China,and water shortage is a critical factor restricting vegetation establishment and growth in this region.Under the influence of global climate change in recent years,significant changes have taken place in climate characteristics of the Loess Plateau,which will have a far-reaching impact on evaporation and transpiration under different vegetation conditions.Therefore,there is needed to make a in-depth research on the response of evaporation and transpiration to climate change for typical afforestation tree species,which has remarkable theoretical and practical significance in providing useful indications for tree species selection,water use efficiency improvement and ecosystem restoration.In order to evaluate the effects and mechanism of climate change on evaporation and transpiration of typical artificial afforestation tree species,a field experiment was carried out in the growing season of 2015-2016(April 15th-October15th)at Nanxiaohegou basin(35°41′-35°44′N,107°30′-107°37′E),a typical small basin in gully region of the Loess Plateau selected by the Yellow River Water Conservancy Commission of China.In three sample plots of Robinia pseudoacacia,Platycladus orientalis and Pinus tabulaeformis,soil physical parameters of three soil depth(0-40 cm,>40-100 and>100-200 cm)and the distribution of root density were measured,and soil moisture content,leaf area index,evaporation,precipitation and meteorology data were observed during the study period,from which simulation models of transpiration and evaporation in three experimental plots were established using Hydrus-1D software.The uncertainty of models parameters were analyzed through the Morris method,and the results showed that parameters of pore size distribution(40–100 cm)(n2),saturated water content(40-100cm)(θs2),field water capacity(θf),optimum threshold for root water absorption(h1),lower threshold for root water absorption(h2),soil water potential for permanent wilting(h3),

关 键 词：气候变化 蒸散发 植被 HYDRUS-1D模型 黄土沟壑区 

分 类 号：S162.5[农业科学—农业气象学]