摘要
通过野外调查与室内试验相结合的方法,对王茂沟流域降水及5种土地利用类型土壤剖面稳定氢氧同位素特征进行对比分析,为黄土区土壤水分运移机制、模型参数识别及生态保护与重建提供科学依据。结果表明:(1)降水与5种土地利用方式下土壤水中δD和δ^(18) O的变化范围分别为(-118.08‰)^(-14.37‰),(-16.13‰)^(1.41‰)和(-92.36‰)^(-34.98‰),(-12.48‰)^(-5.01‰),平均值分别为-37.36‰,-5.65‰和-60.18‰,-7.81‰。(2)不同土地利用类型的土壤水氢氧同位素变化存在显著性差异,土壤通透性草地>梯田>林地>坝地>坡耕地,表层土壤水分的蒸发分馏程度梯田>草地>坝地>坡耕地>林地。(3)林地和草地"优先流"现象明显,草地"优先流"程度最大,林地能显著延伸"优先流"发生路径。(4)草地、林地和梯田分别在160,200,200cm土层及以下氢氧同位素值相对稳定,坝地和坡耕地可能对地下水水质与补给造成较大影响。
In this study,stable isotope compositions of the precipitation and soil water of five different kinds of land use patterns in Wangmao ditch small watershed on the Loess Plateau were analyzed,the aim was to understand the characteristics of stable isotopes along the soil profile,and provide a scientific basis for understanding the mechanisms of soil water movement,the identification of model parameters and the ecological protection and reconstruction.The results showed that：（1）The variation ranges ofδD（orδ^18O）in the precipitation was from-118.08‰（or-16.13‰）to-14.37‰（or 1.41‰）,with a mean value of-37.36‰（or-5.65‰）.The variation range ofδD（orδ^18 O）in soil water of five kinds of land use was from-92.36‰（or-12.48‰）to-34.98‰（or-5.01‰）,with a mean value of-60.18‰（or-7.81‰）.（2）There were significant differences in the changes of hydrogen and oxygen isotope.Soil permeability of the five kinds of land use was as follows：grassland〉terraced fields〉forest land〉 dam land〉slope cropland.Soil water evaporation fractionation in different land use patterns was as follows：terraced fields 〉grassland〉 dam land 〉slope cropland 〉forest land.（3）The woodland and grassland＂preferential flow＂phenomenon was obvious;the grassland＂preferential flow＂was the maximal,and the woodland could extend the＂preferential flow＂path obviously.（4）Hydrogen and oxygen isotopic values in the 160,200 and 〉200cm soil layers of the grassland,woodland,and terrace were relatively stable.The dam land and sloping farmland might affect the quality and recharge of groundwater significantly.
作者
柯浩成
李占斌
李鹏
肖列
张军
刘莹
赵宾华
常恩浩
王琦
KE Haocheng LI Zhanbin LI Peng XIAO Lie ZHANG Jun LIU Ying ZHAO Binhua CHANG Enhao WANG Qi(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, Yangling, Shaanxi 712100)
出处
《水土保持学报》
CSCD
北大核心
2017年第3期298-303,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金重点项目(41330858)
国家自然科学基金项目(41471226
41401316)
国家重点研发计划(2016YFC0402404)
关键词
降水
土壤水
氢氧同位素
水分运移
黄土区
precipitation
soil water
hydrogen and oxygen isotope
water movement
the Loess Plateau
