DOI: 10.5194/hess-19-4183-2015
Scopus记录号: 2-s2.0-84945259770
论文题名: Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations
作者: Camacho Suarez V ; V ; , Saraiva Okello A ; M ; L ; , Wenninger J ; W ; , Uhlenbrook S
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2015
卷: 19, 期: 10 起始页码: 4183
结束页码: 4199
语种: 英语
Scopus关键词: Arid regions
; Catchments
; Groundwater
; Hydrochemistry
; Isotopes
; Reservoirs (water)
; Soil moisture
; Source separation
; Surface waters
; Sustainable development
; Water resources
; Arid and semi-arid areas
; High evaporation rate
; Hydrograph separation
; Runoff generation mechanisms
; Semi-arid environments
; Streamflow variability
; Surface water and groundwaters
; Sustainable management
; Runoff
; catchment
; drought
; flood
; groundwater
; hydrochemistry
; hydrograph
; hydrological modeling
; isotopic composition
; overland flow
; prediction
; reservoir
; runoff
; semiarid region
; stream channel
; sustainable development
; tracer
; South Africa
英文摘要: The understanding of runoff generation mechanisms is crucial for the sustainable management of river basins such as the allocation of water resources or the prediction of floods and droughts. However, identifying the mechanisms of runoff generation has been a challenging task, even more so in arid and semi-arid areas where high rainfall and streamflow variability, high evaporation rates, and deep groundwater reservoirs may increase the complexity of hydrological process dynamics. Isotope and hydrochemical tracers have proven to be useful in identifying runoff components and their characteristics. Moreover, although widely used in humid temperate regions, isotope hydrograph separations have not been studied in detail in arid and semi-arid areas. Thus the purpose of this study is to determine whether isotope hydrograph separations are suitable for the quantification and characterization of runoff components in a semi-arid catchment considering the hydrological complexities of these regions. Through a hydrochemical characterization of the surface water and groundwater sources of the catchment and two- and three-component hydrograph separations, runoff components of the Kaap catchment in South Africa were quantified using both isotope and hydrochemical tracers. No major disadvantages while using isotope tracers over hydrochemical tracers were found. Hydrograph separation results showed that runoff in the Kaap catchment is mainly generated by groundwater sources. Two-component hydrograph separations revealed groundwater contributions of between 64 and 98 % of total runoff. By means of three-component hydrograph separations, runoff components were further separated into direct runoff, shallow and deep groundwater components. Direct runoff, defined as the direct precipitation on the stream channel and overland flow, contributed up to 41 % of total runoff during wet catchment conditions. Shallow groundwater defined as the soil water and near-surface water component (and potentially surface runoff) contributed up to 45 % of total runoff, and deep groundwater contributed up to 84 % of total runoff. A strong correlation for the four studied events was found between the antecedent precipitation conditions and direct runoff. These findings suggest that direct runoff is enhanced by wetter conditions in the catchment that trigger saturation excess overland flow as observed in the hydrograph separations. © Author(s) 2015. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/78407
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Water Science and Engineering, UNESCO, IHE Institute for Water Education, P.O. Box 3015, Delft, Netherlands; Section of Water Resources, Delft University of Technology, P.O. Box 5048, Delft, Netherlands
Recommended Citation:
Camacho Suarez V,V,, Saraiva Okello A,et al. Understanding runoff processes in a semi-arid environment through isotope and hydrochemical hydrograph separations[J]. Hydrology and Earth System Sciences,2015-01-01,19(10)