干旱区生态环境知识资源中心(Arid): Signatures of human intervention - or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change

Arid

DOI	10.5194/hess-25-1943-2021
	Signatures of human intervention - or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change
	Roodari, Artemis; Hrachowitz, Markus; Hassanpour, Farzad; Yaghoobzadeh, Mostafa
通讯作者	Roodari, A (corresponding author), Delft Univ Technol, Fac Civil Engn & Geosci, Dept Water Management, Stevinweg 1, NL-2628 CN Delft, Netherlands. ; Roodari, A (corresponding author), Univ Zabol, Fac Soil & Water Sci, Dept Water Engn, Zabol 98615538, Iran.
来源期刊	HYDROLOGY AND EARTH SYSTEM SCIENCES
ISSN	1027-5606
EISSN	1607-7938
出版年	2021
卷号	25 期号:4 页码:1943-1967
英文摘要	The transboundary Helmand River basin (HRB) is the main drainage system for large parts of Afghanistan and the Sistan region of Iran. Due to the reliance of this arid region on water from the Helmand River, a better understanding of hydrological-drought pattern and the underlying drivers in the region is critically required for effective management of the available water. The objective of this paper is therefore to analyze and quantify spatiotemporal pattern of drought and the underlying processes in the study region. More specifically we test for the Helmand River basin the following hypotheses for the 1970-2006 period: (1) drought characteristics, including frequency and severity, systematically changed over the study period; (2) the spatial pattern and processes of drought propagation through the Helmand River basin also changed; and (3) the relative roles of climate variability and human influence on changes in hydrological droughts can be quantified. It was found that drought characteristics varied throughout the study period but largely showed no systematic trends. The same was observed for the time series of drought indices SPI (standard precipitation index) and SPEI (standardized precipitation evapotranspiration index), which exhibited considerable spatial coherence and synchronicity throughout the basin, indicating that, overall, droughts similarly affect the entire HRB with few regional or local differences. In contrast, analysis of the SDI (streamflow drought index) exhibited significant negative trends in the lower parts of the basin, indicating an intensification of hydrological droughts. It could be shown that with a mean annual precipitation of similar to 250 mm yr(-1), streamflow deficits and thus hydrological drought throughout the HRB are largely controlled by precipitation deficits, whose annual anomalies on average account for similar to 50 mm yr(-1), or similar to 20% of the water balance of the HRB, while anomalies of total evaporative fluxes on average only account for similar to 20 mm yr(-1). Assuming no changes in the reservoir management practices over the study period, the results suggest that the two reservoirs in the HRB only played a minor role for the downstream propagation of streamflow deficits, as indicated by the mean difference between inflow and outflow during drought periods, which did not exceed similar to 0.5% of the water balance of the HRB. Irrigation water abstraction had a similarly limited effect on the magnitude of streamflow deficits, accounting for similar to 10% of the water balance of the HRB. However, the downstream parts of the HRB moderated the further propagation of streamflow deficits and associated droughts because of the minor effects of reservoir operation and very limited agricultural water in the early decades of the study period. This drought moderation function of the lower basin was gradually and systematically inverted by the end of the study period, when the lower basin eventually amplified the downstream propagation of flow deficits and droughts. Our results provide plausible evidence that this shift from drought moderation to drought amplification in the lower basin is likely a consequence of increased agricultural activity and the associated increases in irrigation water demand, from similar to 13 mm yr(-1) at the beginning of the study period to similar to 23 mm yr(-1) at the end, and thus in spite of being only a minor fraction of the water balance. Overall the results of this study illustrate that flow deficits and the associated droughts in the HRB clearly reflect the dynamic interplay between temporally varying regional differences in hydro-meteorological variables together with subtle and temporally varying effects linked to direct human intervention.
类型	Article
语种	英语
开放获取类型	Green Submitted, gold
收录类别	SCI-E
WOS记录号	WOS:000640252800001
WOS类目	Geosciences, Multidisciplinary ; Water Resources
WOS研究方向	Geology ; Water Resources
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/350517
作者单位	[Roodari, Artemis; Hrachowitz, Markus] Delft Univ Technol, Fac Civil Engn & Geosci, Dept Water Management, Stevinweg 1, NL-2628 CN Delft, Netherlands; [Roodari, Artemis; Hassanpour, Farzad] Univ Zabol, Fac Soil & Water Sci, Dept Water Engn, Zabol 98615538, Iran; [Yaghoobzadeh, Mostafa] Univ Birjand, Dept Water Engn, Birjand 97175615, Iran
推荐引用方式 GB/T 7714	Roodari, Artemis,Hrachowitz, Markus,Hassanpour, Farzad,et al. Signatures of human intervention - or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change[J],2021,25(4):1943-1967.
APA	Roodari, Artemis,Hrachowitz, Markus,Hassanpour, Farzad,&Yaghoobzadeh, Mostafa.(2021).Signatures of human intervention - or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change.HYDROLOGY AND EARTH SYSTEM SCIENCES,25(4),1943-1967.
MLA	Roodari, Artemis,et al."Signatures of human intervention - or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change".HYDROLOGY AND EARTH SYSTEM SCIENCES 25.4(2021):1943-1967.