DOI: 10.5194/hess-19-4229-2015
Scopus记录号: 2-s2.0-84945551075
论文题名: Groundwater-dependent ecosystems: Recent insights from satellite and field-based studies
作者: Eamus D ; , Zolfaghar S ; , Villalobos-Vega R ; , Cleverly J ; , Huete A
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2015
卷: 19, 期: 10 起始页码: 4229
结束页码: 4256
语种: 英语
Scopus关键词: Aquifers
; Ecology
; Ecosystems
; Evapotranspiration
; Extraction
; Forestry
; Groundwater
; Hydrogeology
; Isotopes
; Remote sensing
; Transpiration
; Arid and semi-arid regions
; Ground water depths
; Ground water discharge
; Groundwater dependent ecosystems
; Groundwater extraction
; Groundwater modelling
; Stable-isotope analysis
; Variable saturation
; Groundwater resources
; aquifer
; dieback
; ecohydrology
; ecological impact
; ecosystem structure
; eddy covariance
; evergreen forest
; field method
; groundwater abstraction
; hydrological modeling
; remote sensing
; satellite data
; transpiration
; vegetation index
英文摘要: Groundwater-dependent ecosystems (GDEs) are at risk globally due to unsustainable levels of groundwater extraction, especially in arid and semi-arid regions. In this review, we examine recent developments in the ecohydrology of GDEs with a focus on three knowledge gaps: (1) how do we locate GDEs, (2) how much water is transpired from shallow aquifers by GDEs and (3) what are the responses of GDEs to excessive groundwater extraction? The answers to these questions will determine water allocations that are required to sustain functioning of GDEs and to guide regulations on groundwater extraction to avoid negative impacts on GDEs. We discuss three methods for identifying GDEs: (1) techniques relying on remotely sensed information; (2) fluctuations in depth-to-groundwater that are associated with diurnal variations in transpiration; and (3) stable isotope analysis of water sources in the transpiration stream. We then discuss several methods for estimating rates of GW use, including direct measurement using sapflux or eddy covariance technologies, estimation of a climate wetness index within a Budyko framework, spatial distribution of evapotranspiration (ET) using remote sensing, groundwater modelling and stable isotopes. Remote sensing methods often rely on direct measurements to calibrate the relationship between vegetation indices and ET. ET from GDEs is also determined using hydrologic models of varying complexity, from the White method to fully coupled, variable saturation models. Combinations of methods are typically employed to obtain clearer insight into the components of groundwater discharge in GDEs, such as the proportional importance of transpiration versus evaporation (e.g. using stable isotopes) or from groundwater versus rainwater sources. Groundwater extraction can have severe consequences for the structure and function of GDEs. In the most extreme cases, phreatophytes experience crown dieback and death following groundwater drawdown.We provide a brief review of two case studies of the impacts of GW extraction and then provide an ecosystem-scale, multiple trait, integrated metric of the impact of differences in groundwater depth on the structure and function of eucalypt forests growing along a natural gradient in depth-to-groundwater. We conclude with a discussion of a depth-to-groundwater threshold in this mesic GDE. Beyond this threshold, significant changes occur in ecosystem structure and function. © 2015 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78405
Appears in Collections: 气候变化事实与影响
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作者单位: National Centre for Groundwater Research and Training, University of Technology Sydney, P.O. Box 123, Sydney, NSW, Australia; School of Life Sciences, University of Technology Sydney, P.O. Box 123, Sydney, NSW, Australia
Recommended Citation:
Eamus D,, Zolfaghar S,, Villalobos-Vega R,et al. Groundwater-dependent ecosystems: Recent insights from satellite and field-based studies[J]. Hydrology and Earth System Sciences,2015-01-01,19(10)