次降雨事件下雨养区典型小流域土壤水分运移规律  

Soil Moisture Migration Characteristics of Typical Small Watershed in Rain Feed Region Under Individual Rainfall Events

作　　者：马田田[1] 柯浩成 李占斌[1,2] 李鹏[1] 肖列[1] 张洋[1] 汤珊珊[1] 郑淋峰 苏远逸 白璐璐[1] MA Tiantian;KE Haocheng;LI Zhanbin;LI Peng;XIAO Lie;ZHANG Yang;TANG Shanshan;ZHENG Linfeng;SU Yuanyi;BAI Lulu(State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area , Xi＇ an University of Technology, Xi＇an 710048;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling , Shaanxi 712100)

机构地区：[1]西安理工大学省部共建西北旱区生态水利工程国家重点实验室,西安710048 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《水土保持学报》2018年第2期80-86,共7页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目(2016YFC0402404;2017YFC0504704);国家自然科学基金重点项目(41330858)

摘　　要：以黄土丘陵沟壑区典型小流域为研究对象,采用稳定同位素分析法,结合野外调查和室内试验,对绥德县王茂沟小流域次降雨事件后不同土地利用下包气带土壤水稳定氢同位素(δ2 H)变化规律进行剖析,为黄土丘陵沟壑区包气带土壤水分运移机理、模型参数确定以及生态保护与建设提供科学依据。结果表明:(1)草地、林地和农地土壤含水率的变化范围分别为6.74%~21.42%,6.74%~19.08%和7.86%~20.74%,土壤蓄水量的变化范围分别为265.6~384.0,275.1~368.7,289.5~334.6mm,土壤水δ2 H的变化范围分别为-113.41‰^-71.84‰,-115.10‰^-50.98‰和-112.28‰^-63.78‰。(2)草地、林地和农地土壤含水率变化趋势均存在时间节点。(3)不同土地利用下的包气带土壤水氢稳定同位素变化存在显著性差异,农地和草地较林地更有利于赋存土壤水分。(4)不同土地利用下土壤蓄水量峰值与蓄水能力呈负相关关系,峰值越大,相应的蓄水能力越低。(5)林地、草地和农地均存在"优先流"现象,草地和林地能显著延伸"优先流"发生路径,农地可能与地下水水质与补给密切相关。The research area of this study was the Wangmao small watershed in Suide county of the Loess Plateau of China.Combining with the field investigation and laboratory test,the variations of stable isotopes（δ-2H）in the vadose zone under three different land use types were studied in a single rainfall event.The results showed that：（1）The soil water content ranged from 6.74% to 21.42% in grassland,from 6.74% to19.08% in woodland,and from 7.86% to 20.74%in farmland.The variation ranges of soil water storage were from 265.6 mm to 384.0 mm in grassland,from 275.1 mm to 368.7 mm in woodland,and from 289.5 mm to 334.6 mm in farmland.The variation ranges of δ-2H in soil water were from -113.41‰ to-71.84‰ in grassland,from-115.10‰ to-50.98‰ in woodland,and from -112.28‰ to -63.78‰ in farmland.（2）There were two trends in soil water content changes in grassland,woodland and farmland,but with difference in time nodes.（3）There were significant differences in the hydrogen isotopic changes of soil water in different land use types.The farmland and grassland were favorable for the soil water retention,but it was not easy for the woodland to maintain soil moisture.（4）The peak values of soil water storage under different land use types were inversely related to the water storage capacity.The higher the peak value,the lower the corresponding water storage capacity.（5）There were preferential flow phenomena in all land uses studied,with the largest preferential flow in woodland.The path of preferential flow was extended in grassland and woodland,whereas in farmland,it might be affected by the quality and recharge of groundwater.

关 键 词：降水 土壤水 氢同位素 水分运移 黄土丘陵沟壑区 

分 类 号：S157.1[农业科学—土壤学] S152.7[农业科学—农业基础科学]