GROUNDWATER GOVERNANCE Priorities to Sustain a Critical Resource Prof Dr Stephen Foster Global Water...
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Transcript of GROUNDWATER GOVERNANCE Priorities to Sustain a Critical Resource Prof Dr Stephen Foster Global Water...
GROUNDWATER GOVERNANCE Priorities to
Sustain a Critical Resource
Prof Dr Stephen FosterGlobal Water Partnership–Senior Adviser
International Association of Hydogeologists–Past President
GLOBAL WATER PARTNERSHIP
FAO-UN Investment Days 2014
Global WaterPartnership
GROUNDWATER – A GLOBAL OVERVIEW • Strategic Importance & Sustainability Concerns
• Intimate Relation with Irrigated Agriculture • Strengthening Groundwater Governance• Specific & Urgent Investment Priorities
GROUNDWATER – NATURAL DISCHARGE fundamental role in sustaining aquatic ecosystems
FRESHWATER DISCHARGE TO COASTAL
LAGOONS
NATURAL BASEFLOW TO RIVER ECOSYSTEMS
• groundwater – the ‘traditional role’ source of >50% (rural/urban) drinking water-supply
REGIONGROUNDWATER
IRRIGATION AREA Mha total
GROUNDWATER VOLUME USED
km3/a propn
GLOBAL TOTAL 112.9 38% 545 43%
South Asia(India/Pakistan)
48.3 57% 262 57%
East Asia (China) 19.3 29% 57 34%
South-East Asia 1.0 5% 3 6%
Mid-East & North Africa
12.9 43% 87 44%
Latin America 2.5 18% 8 19%
Sub-Saharan Africa 0.4 6% 2 7%
GROUNDWATER IRRIGATION USE
the global boom
• groundwater extraction increased 300% in 50 years (1960-2010)
• massive growth of irrigation waterwells in some regions facilitated by government (energy subsidies/construction loans/crop guarantees)
(Siebert et al, 2010 for FAO-UN)
GROUNDWATER DEPLETION – NEGATIVE EXTERNALITIES onset and impact varies widely with aquifer type
• energy consumption• carbon footprint
• contribution sea-level rise
GROUNDWATER DEVELOPMENT STAGES environmental and socio-economic impacts
GROUNDWATER RESOURCE DEPLETION a widespread and accelerating phenomenon
Konikow, 2011
• ~15% of existing staple grain
irrigated with non-renewable groundwater resources• mining of fossil
groundwater during 1955-2005 contributed 10-15 mm to sea-level rise
GROUNDWATER – A GLOBAL OVERVIEW • Strategic Importance & Sustainability Concerns
• Intimate Relation with Irrigated Agriculture • Strengthening Groundwater Governance• Specific & Urgent Investment Priorities
IRRIGATED AGRICULTURE & GROUNDWATER RESOURCES an intimate multi-facetted relationship
• irrigated land-use practices are a major influence on groundwater recharge
• groundwater salinisation is a serious and complex threat associated with irrigated agriculture in more arid climates
• groundwater very popular with farmers (self control/direct local access/drought secure)
irrigated agriculture is the major consumer of groundwater resources
• agricultural land-use is a ‘leaky activity’ and a major source of diffuse groundwater pollution
• scientific tools now available to characterise the dynamics of these interactions with confidence and in
detail
SURFACE-WATER IRRIGATION MANAGEMENT effect on groundwater recharge rates and quality
permeable soil profiles
quality cannot be divorced from
quantity
PERU-ICA VALLEY : ASPARAGUS PRODUCTION sustainability threatened by decreasing recharge
Dddddddddddd
Ddddddddddd
• relatively stable groundwater abstraction over past 50 years
• recent falling water-table due to
abandoning spate/flood irrigation
• modernisation of irrigated cropping
with increasing consumptive use –
urgently needs supporting by managed recharge measures
PAKISTAN PUNJABgrowing groundwater dependence for staple crop production
but continuing long-run battle with the ‘salinity dragon’
arid zone with fresh groundwater recharge primarily from riverbed and irrigation canal seepage – but freshwater salinity increasing
due to salt fractionation in irrigated soils, extensive phreatic evaporation and use of deep irrigation waterwells
semi-arid zone with diffuse groundwater recharge
from annual monsoonal rainfall
GROUNDWATER SYSTEM SALINISATION factors entering into aquifer salt balances in arid
areasfreshwaterrecharge
return watersvarying salinity
other factors in aquifer salt balances :• drawing-in from phreatic and
vadose zone salinity • mobilisation via deep waterwells
• inflow from saline formations
mmm
DIFFUSE POLLUTION FROM
AGRICULTURAL LAND-USE
nutrient leaching
pesticide mobility
Cryptosporidium hazard
saline returns
cultivation of permeable soils is a ‘leaky activity’ – farmers cultivating land also (accidentally) harvest
groundwater
GROUNDWATER – A GLOBAL OVERVIEW • Strategic Importance & Sustainability Concerns
• Intimate Relation with Irrigated Agriculture • Strengthening Groundwater Governance• Specific & Urgent Investment Priorities
historically groundwater resources have largely been ‘abandoned to chance’ in face of agricultural
development ‘business-as-usual’ will result in further irreversible degradation and growing conflict
government role must transform from ‘promoter of short-term development’ to ‘long-term resource guardian’
widespread need to strengthen governance provisions : building effective institutions creating an adequate base making essential linkages aligning financial incentives implementing management plans
promote more integrated and sustainable policy with appropriate monitoring and assessment as basis for adaptive management to cope with global change
GROUNDWATER GOVERNANCE & MANAGEMENT
size matters – understand context
evident governance provisions/ management approaches must to a degree be context
specific and take account of :
HYDROGEOLOGICAL SETTING• Groundwater Resource
Renewability• Susceptibility to Degradation
• Scale of Aquifer Storage • Connectivity with Surface Water
POLITICAL ECONOMY OF RESOURCE • Propn of Population Using
Waterwells• Number of Abstraction Points
• Economic Significance of Resource Use
• Capacity of Water Resources Agency
‘one size cannot fit all’ Groundwater Resource Management
TAILOR TO CONTEXT
GROUNDWATER – A GLOBAL OVERVIEW • Strategic Importance & Sustainability Concerns
• Intimate Relation with Irrigated Agriculture • Strengthening Groundwater Governance• Specific & Urgent Investment Priorities
CONJUNCTIVE USE FOR IRRIGATED AGRICULTUREmanaged evolution from spontaneous to planned development
SPONTANEOUS PLANNED
waterlogging & salinization risk if
water-table shallow
groundwaterdepletion risk
GROUNDWATER & IMPROVED IRRIGATION TECHNOLOGY ‘irrigation-water efficiency’ a misleading term
• ‘irrigation-water efficiency’ improved 40% to 80% (230 mm for wheat crop)
• but ‘real water-resource savings’ (reductions in non-beneficial evaporation)
only by 55 mm for crop (< 40 mm/a over entire land area) • most so-called ‘water losses’ were in fact irrigation returns to
groundwater
• modifying monsoon rice cultivation in Indian Punjab more successful –
delayed-planting generated reduction in non-beneficial evaporation of 90-100 mm/a for rice crop (80-90 mm/a over entire land area)
DEMAND MANAGEMENT• align fiscal incentives in support of resource sustainability (construction grants, electricity subsidies, crop guarantee prices)
• regulate waterwell extraction and consumptive use (‘smarter approaches’ to controlling waterwell use) (focus on reduction of non-beneficial evapotranspiration) (innovative use of financial nexus with energy
provision/charging)
SUPPLY ENHANCEMENT reward land stewardship that augments recharge promote productive land-use that protects groundwater
quality
INSTITUTIONAL FOUNDATION• strengthen government agency capacity to administer
resource• integrate responsibility for resource conservation
and quality protection • establish essential linkages with dependent
sectors/activities nuture stakeholder participation via financial
and regulatory support improve groundwater system and soil-water accounting (including groundwater level/quality status monitoring –
with telemetry to provide basis for adaptive management)
• finance revenue cost of monitoring (from selective levying of a resource fee)
promote and optimise conjunctive use with canal-water in alluvial systems (understanding physical connectivity and overcoming socioeconomic impediments)
GROUNDWATER GOVERNANCE
Priorities to Sustain a Critical Resource Prof Dr Stephen Foster
Global Water Partnership–Senior Adviser
International Association of Hydogeologists–Past President
GLOBAL WATER PARTNERSHIP
FAO-UN Investment Days 2014
Global WaterPartnership