DOI: 10.5194/hess-21-1757-2017
Scopus记录号: 2-s2.0-85016411713
论文题名: Soil water migration in the unsaturated zone of semiarid region in China from isotope evidence
作者: Yang Y ; , Fu B
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2017
卷: 21, 期: 3 起始页码: 1757
结束页码: 1767
语种: 英语
Scopus关键词: Arid regions
; Ecology
; Evaporation
; Groundwater
; Groundwater flow
; Isotopes
; Landforms
; Mixing
; Model structures
; Plants (botany)
; Restoration
; Sediments
; Soil moisture
; Water management
; Water piping systems
; Water resources
; Caragana korshinskii kom
; China's loess plateaux
; Ecological restoration
; Ecological water demand
; Identification of model
; Isotopic fractionations
; Oxygen and hydrogen isotopes
; Transformation pathways
; Soils
; arid region
; deuterium
; gully erosion
; hydrological modeling
; isotopic composition
; isotopic fractionation
; meteoric water
; oxygen isotope
; plant water relations
; precipitation (chemistry)
; preferential flow
; river basin
; semiarid region
; soil water
; vadose zone
; water chemistry
; water resource
; China
; Loess Plateau
; Caragana korshinskii
英文摘要: Soil water is an important driving force of the ecosystems, especially in the semiarid hill and gully region of the northwestern Loess Plateau in China. The mechanism of soil water migration in the reconstruction and restoration of Loess Plateau is a key scientific problem that must be solved. Isotopic tracers can provide valuable information associated with complex hydrological problems, difficult to obtain using other methods. In this study, the oxygen and hydrogen isotopes are used as tracers to investigate the migration processes of soil water in the unsaturated zone in an arid region of China's Loess Plateau. Samples of precipitation, soil water, plant xylems and plant roots are collected and analysed. The conservative elements deuterium (D) and oxygen (18O) are used as tracers to identify variable source and mixing processes. The mixing model is used to quantify the contribution of each end member and calculate mixing amounts. The results show that the isotopic composition of precipitation in the Anjiagou River basin is affected by isotopic fractionation due to evaporation. The isotopic compositions of soil waters are plotted between or near the local meteoric water lines, indicating that soil waters are recharged by precipitation. The soil water migration is dominated by piston-type flow in the study area and rarely preferential flow. Water migration exhibited a transformation pathway from precipitation to soil water to plant water. δ18O and δD are enriched in the shallow (<20 cm depth) soil water in most soil profiles due to evaporation. The isotopic composition of xylem water is close to that of soil water at the depth of 40-60 cm. These values reflect soil water signatures associated with Caragana korshinskii Kom. uptake at the depth of 40-60 cm. Soil water from the surface soil layer (20-40 cm) comprised 6-12 % of plant xylem water, while soil water at the depth of 40-60 cm is the largest component of plant xylem water (ranging from 60 to 66 %), soil water below 60 cm depth comprised 8-14 % of plant xylem water and only 5-8 % is derived directly from precipitation. This study investigates the migration process of soil water, identifies the source of plant water and finally provides a scientific basis for identification of model structures and parameters. It can provide a scientific basis for ecological water demand, ecological restoration, and management of water resources. © The Author(s) 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79214
Appears in Collections: 气候变化事实与影响
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作者单位: Institute of Loess Plateau, Shanxi University, Taiyuan, Shanxi, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Yang Y,, Fu B. Soil water migration in the unsaturated zone of semiarid region in China from isotope evidence[J]. Hydrology and Earth System Sciences,2017-01-01,21(3)