Increasing probability of concurrent drought between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project, China

doi:10.1007/s11442-022-2033-2

Abstract

Abstract:

Water diversion projects are an effective measure to mitigate water shortages in water-limited areas. Understanding the risk of such projects increasing concurrent drought between the water intake and receiving regions is essential for sustainable water management. This study calculates concurrent drought probability between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project using Standardized Precipitation Index and Copula functions. Results showed an increasing trend in drought probability across both the water intake and receiving regions from 2.67% and 8.38% to 12.47% and 14.18%, respectively, during 1969-2018. The return period of concurrent drought decreased from 111.11 to 13.05 years, indicating larger risk of simultaneous drought between the two regions. Projections from CMIP6 suggested that under the SSP 2-4.5 and 5-8.5 scenarios, concurrent drought probability would increase by 2.40% and 7.72% in 2019-2050 compared to that in 1969-1990, respectively. Although increases in precipitation during 2019-2050 could potentially alleviate drought conditions relative to those during 1991-2018, high precipitation variability adds to the uncertainty about future concurrent drought. These findings provide a basis for better understanding concurrent drought and its impact on water diversion projects in a changing climate, and facilitate the establishment of adaptation countermeasures to ensure sustainable water availability.

Key words: concurrent drought, climate change, Copula, SPI, Hanjiang to Weihe River Water Diversion Project

WANG Xiaohong, LIU Xianfeng, SUN Gaopeng. Increasing probability of concurrent drought between the water intake and receiving regions of the Hanjiang to Weihe River Water Diversion Project, China[J].Journal of Geographical Sciences, 2022, 32(10): 1998-2012.

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Name of the Subproject	Location	Water storage (10⁶ m³)	Maximum height (m)	Designed discharge (m³/s)	Function
Huangjinxia Water Control Project	Upper Hanjiang, 62 km from Yang County	229	68	70	Water supply, power generation and improvement of navigation conditions
Sanhekou Water Control Project	2 km from the junction of Jiaoxi River, Pu River and Wenshui River	710	145	50	Regulating and storing water
Qinling water conveyance tunnel	Connect the Sanhekou Water Control Project and the Huangchi River in Zhouzhi County	/	/	70	Transport water

Name	ID	Longitude	Latitude	Elevation (m)
Changwu	53929	35°12'N	107°48'E	1206.5
Tongchuan	53947	35°05'N	109°04'E	978.9
Baoji	57016	34°21'N	107°08'E	612.4
Fengxiang	57025	34°31'N	107°23'E	781.1
Yaoxian	57037	34°56'N	108°59'E	710.0
Huashan	57046	34°29'N	110°05'E	2064.9
Lueyang	57106	33°19'N	106°09'E	794.2
Hanzhong	57127	33°04'N	107°02'E	509.5
Foping	57134	33°31'N	107°59'E	827.2
Shangzhou	57143	33°52'N	109°58'E	742.2
Zhenan	57144	33°26'N	109°09'E	693.7
Shiquan	57232	33°03'N	108°16'E	484.9
Wugong	57234	34°15'N	108°13'E	447.8
Ankang	57245	32°43'N	109°02'E	290.8

Model abbreviation	Institute ID	Horizontal resolution (°lon × °lat)	Ensembles variables		Study area
Model abbreviation	Institute ID	Horizontal resolution (°lon × °lat)	Ensembles variables		Water intake	Water receiving
BCC-CSM2-MR	BCC	1.125, 1.125 (gn)	r1i1p1f1	pr	0.5938	0.5388
BCC-CSM2-MR	BCC	1.125, 1.125 (gn)	r1i1p1f1	ta	0.9732	0.9738
CNRM-CM6-1	CNRM-CERFACS	1.406, 1.406 (gr)	r1i1p1f1	pr	0.4633	0.4126
FGOALS-f3-L	LASG-CESS	1.25, 1 (gr)	r1i1p1f1	pr	0.5778	0.5135
GFDL-ESM4	NOAA GFDL	1.25, 1 (gr1)	r1i1p1f1	pr	0.5447	0.5310
MIROC6	MIROC	1.406, 1.406 (gn)	r1i1p1f1	pr	0.5403	0.4820
MRI-ESM2-0	MRI	1.125, 1.125 (gn)	r1i1p1f1	pr	0.4598	0.4101
MPI-ESM1-2-LR	MPI-M	1.875, 1.875 (gn)	r1i1p1f1	ta	0.9739	0.9735

Index value	Category
Extreme drought	SPI ≤ ‒2.0
Severe drought	-2.0 < SPI ≤ ‒1.5
Moderate drought	-1.5 < SPI ≤ ‒1.0
Near normal	-1.0 < SPI ≤ 1.0
Moderately wet	1.0 < SPI ≤ 1.5
Very wet	1.5 < SPI ≤ 2.0
Extremely wet	SPI > 2.0

Region	Margin	p value
Water intake	Normal	0.9837
	Logistic	0.9057
	Generalized extreme value	0.9675
	t location-scale	0.9762
	Extreme value	0.3369
Water receiving	Normal	0.9246
	Logistic	0.9627
	Generalized extreme value	0.8944
	t location-scale	0.9389
	Extreme value	0.3159