Observed controls on resilience of groundwater to climate variability in sub-Saharan Africa

被引：197

作者：

Cuthbert, Mark O. ^{[1
,2
,3
,4
]}

Taylor, Richard G. ^{[1
]}

Favreau, Guillaume ^{[5
]}

Todd, Martin C. ^{[6
]}

Shamsudduha, Mohammad ^{[1
,7
]}

Villholth, Karen G. ^{[8
]}

MacDonald, Alan M. ^{[9
]}

Scanlon, Bridget R. ^{[10
]}

Kotchoni, D. O. Valerie ^{[11
]}

Vouillamoz, Jean-Michel ^{[12
]}

Lawson, Fabrice M. A. ^{[11
]}

Adjomayi, Philippe Armand ^{[13
]}

Kashaigili, Japhet ^{[14
]}

Seddon, David ^{[1
]}

Sorensen, James P. R. ^{[15
]}

Ebrahim, Girma Yimer ^{[8
]}

Owor, Michael ^{[16
]}

Nyenje, Philip M. ^{[17
]}

Nazoumou, Yahaya ^{[18
]}

Goni, Ibrahim ^{[19
]}

Ousmane, Boukari Issoufou ^{[18
]}

Sibanda, Tenant ^{[20
]}

Ascott, Matthew J. ^{[15
]}

Macdonald, David M. J. ^{[15
]}

Agyekum, William ^{[21
]}

Koussoube, Youssouf ^{[22
]}

Wanke, Heike ^{[23
,24
]}

Kim, Hyungjun ^{[25
]}

Wada, Yoshihide ^{[26
]}

Lo, Min-Hui ^{[27
]}

Oki, Taikan ^{[25
,28
]}

Kukuric, Neno ^{[29
]}

机构：

[1] UCL, Dept Geog, London, England

[2] Cardiff Univ, Sch Earth & Ocean Sci, Cardiff, S Glam, Wales

[3] Univ New South Wales, Connected Waters Initiat Res Ctr, Sydney, NSW, Australia

[4] Cardiff Univ, Water Res Inst, Cardiff, S Glam, Wales

[5] Inst Rech Dev, Niamey, Niger

[6] Univ Sussex, Dept Geog, Falmer, England

[7] UCL, Inst Risk & Disaster Reduct, London, England

[8] Int Water Management Inst, Pretoria, South Africa

[9] British Geol Survey, Lyell Ctr, Edinburgh, Midlothian, Scotland

[10] Univ Texas Austin, Jackson Sch Geosci, Bur Econ Geol, Austin, TX 78712 USA

[11] Univ Abomey Calavi, Inst Natl Eau, Inst Rech Dev, Chaire Int Phys Math& Applicat, Cotonou, Benin

[12] Inst Rech Dev, Grenoble, France

[13] Direct Gen Eau, Cotonou, Benin

[14] Sokoine Univ Agr, Dept Forest Resources Assessment & Management, Morogoro, Tanzania

[15] British Geol Survey, Maclean Bldg, Wallingford, Oxon, England

[16] Makerere Univ, Dept Geol & Petr Studies, Kampala, Uganda

[17] Makerere Univ, Dept Civil & Environm Engn, Kampala, Uganda

[18] Univ Abdou Moumouni, Dept Geol, Niamey, Niger

[19] Univ Maiduguri, Dept Geol, Maiduguri, Nigeria

[20] Cemex, Rugby, England

[21] Water Res Inst, Accra, Ghana

[22] Univ Ouaga Pr Joseph Ki Zerbo, Dept Sci Terre, Ouagadougou, Burkina Faso

[23] Univ Namibia, Dept Geol, Windhoek, Namibia

[24] Univ West England, Dept Geog & Environm Management, Bristol, Avon, England

[25] Univ Tokyo, Inst Ind Sci, Tokyo, Japan

[26] Int Inst Appl Syst Anal, Laxenburg, Austria

[27] Natl Taiwan Univ, Dept Atmospher Sci, Taipei, Taiwan

[28] Univ Tokyo, Inst Future Initiat, Tokyo, Japan

[29] Int Groundwater Resources Assessment Ctr, Delft, Netherlands

来源：

NATURE | 2019年 / 572卷 / 7768期

基金：

日本学术振兴会; 英国工程与自然科学研究理事会; 新加坡国家研究基金会; 英国自然环境研究理事会;

关键词：

RECHARGE; LAND; RAINFALL; IRRIGATION; DYNAMICS; PATTERNS; DIFFUSE; BALANCE; BENIN;

D O I：

10.1038/s41586-019-1441-7

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Groundwater in sub-Saharan Africa supports livelihoods and poverty alleviation(1,2), maintains vital ecosystems, and strongly influences terrestrial water and energy budgets(3). Yet the hydrological processes that govern groundwater recharge and sustainability-and their sensitivity to climatic variability-are poorly constrained(4,5). Given the absence of firm observational constraints, it remains to be seen whether model-based projections of decreased water resources in dry parts of the region(4) are justified. Here we show, through analysis of multidecadal groundwater hydrographs across sub-Saharan Africa, that levels of aridity dictate the predominant recharge processes, whereas local hydrogeology influences the type and sensitivity of precipitation-recharge relationships. Recharge in some humid locations varies by as little as five per cent (by coefficient of variation) across a wide range of annual precipitation values. Other regions, by contrast, show roughly linear precipitation-recharge relationships, with precipitation thresholds (of roughly ten millimetres or less per day) governing the initiation of recharge. These thresholds tend to rise as aridity increases, and recharge in drylands is more episodic and increasingly dominated by focused recharge through losses from ephemeral overland flows. Extreme annual recharge is commonly associated with intense rainfall and flooding events, themselves often driven by large-scale climate controls. Intense precipitation, even during years of lower overall precipitation, produces some of the largest years of recharge in some dry subtropical locations. Our results therefore challenge the 'high certainty' consensus regarding decreasing water resources(4) in such regions of sub-Saharan Africa. The potential resilience of groundwater to climate variability in many areas that is revealed by these precipitation-recharge relationships is essential for informing reliable predictions of climate-change impacts and adaptation strategies.

引用

页码：230 / +

页数：15

共 54 条

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