Linking science and development: Experience from groundwater work in Asia and Africa

Transcription

1 Linking science and development: Experience from groundwater work in Asia and Africa Karen G. Villholth Senior Researcher, Groundwater Management, IWMI-Southern Africa Chair, Danish Chapter of IAH ATV-IAH Session: Groundwater for Growth, Development and Climate Change Adaptation March 6, 2012, Vingsted, Denmark

2 Why does GW need special attention? It is invisible It is an open source/common pool resource It is slow reacting

3 Groundwater is the new agenda Not just MGDs and rural water supply GW is considered key to CCA GW in transboundary cooperation

4 How much water is there?

5 Global figures for GW use Total annual GW abstraction: 1000 km 3 ~ 25% of global water abstraction ~ 8% of renewable GW reserves ~ % of global GW reserves

6 Groundwater use Upper limit for sustainable use GW resources GW used today GW understanding and mgt.

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8 Groundwater withdrawal, cubic km/year Global GW use per country India USA China Bangladesh Pakistan Mexico W.Europe Tunisia South Africa Sri Lanka Vietnam Spain Ghana Shah, 2004

9 Total abstraction Number of wells Sustainable level of ressource development with acceptalbe impacts under present conditions time Baseline situation Incipient stress an Significant stress Unstable development Stable development Availability and accessibility of adequate quality groundwater greatly exceeds small dispersed demand Registration of wells required, together with maps of occurrence of usable resources Growth of aquifer pumping, but only few local conflicts between neighbouring abstractors Simple management tools (e.g. appropriate well-spacing according to aquifer properties) Abstraction expanding rapidly with impacts on natural regime and strong dependence of stakeholders on ressource Regulatory framework needed, based on comprehensive assessment Excessive abstraction with irreversible aquifer deterioration and stakeholder conflicts Regulatory framework with demand managemnt and/or artificial recharge urgently needed High-level of abstraction, but sound balance between stakeholder interests and ecosystem needs Integrated management with high-level of user self-regulation, aquifer modeling and monitoring

10 300 m! The hidden drought

11 GW for agriculture, Africa vs. Asia <5% of cropland in Africa is irrigated, comp. to 33% in Asia <1% of cropland irrig. with GW in Africa, comp. to 70 % in India Country Groundwater Irrigated Area (Ha) Percent of Arable Land Botswana Burkina Faso 3, Ethiopia 2, Ghana 12, Kenya Malawi Mali Mozambique Niger 1, Nigeria 64, South Africa 127, Sudan (N&S) 29, Tanzania 17, Uganda Zambia 6, Zimbabwe 14,

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15 Artificial recharge/buffer storage Reservoir storage per capita: Ethiopia 43m 3 South Africa 750m 3 North America 6150m 3

16 Various techniques Aquifer storage and recovery

17 Concept of GW drought Calow et al. (1997)

18 Groundwater drought vulnerability in SADC Present Scenario based on IPCC SRES A1B

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20 Major river basins of Africa Major aquifers of Africa

21 Transboundary aquifers and river basins

22 Transboundary GW

23 Why are transboundary aquifers (TBAs) important? They contain large storages of underground water If properly developed and managed they can benefit human development. Otherwise risk of conflicts They can work as a leverage for better national GW mgt. as well as international cooperation

24 Denmark completely dependent on GW Mostly domestic and industrial use Only little water used for irrigation (30%). Mostly rainfed agriculture Annual extraction: ca. 700 mill. m 3 (0.3 % of India)

25 Prospection to protection

26 Key messages GW is becoming a key priority in development agendas More GW emphasis and development need to go hand in hand with multi-disciplinary expertise GW has great potentials but the right precautionary, adaptive management is needed Policy work is needed to have GW taken seriously and realistically GW mgt. needs work at all levels from community to international Denmark should be at the forefront in addressing this challenge Knowledge base is there but needs to be adapted to the international/development context Missing out on this opportunity is decisive for DK s development credibility in the water sector

27 Recommendations DANIDA and other DK development partners to acknowledge that GW is more than rural water supply Integrated challenges related to GW to be specifically addressed by DANIDA and other development strategies DANIDA and other DK development partners to engage GW professionals with multi-disciplinary knowledge and experience DANIDA to set up a long-term collaboration and funding mechanisms with relevant Danish knowledge base org s for technical and policy support related to GW

28 Thank you! Contact: Visit:Karen Villholth