Elizabeth Curmi, Keith Richards, Richard Fenner, Julian.M Allwood, Bojana Bajželj and Grant M. Kopec

Transcription

1 A new representation of integrated management of water resources: Sankey diagrams that link water sources and services for humans and nature at different scales Elizabeth Curmi, Keith Richards, Richard Fenner, Julian.M Allwood, Bojana Bajželj and Grant M. Kopec

2 The Foreseer Project Water Land Energy Nexus Integrated resource use To identify where changing one resource impacts on others (eg biofuels) Sources to Services Surface water, groundwater etc Line thickness proportional to fluxes Food, Industry, Domestic etc Sankey Diagrams Provide a visualisation tool Track the various transformations from source to service (pumping, treatment) Highlight inter-dependencies (multiple connected diagrams) Can be rendered dynamic (scenarios of future climate and socio-economies) An inter-disciplinary project 7 Departments in the University Funded by BP Energy Sustainability Challenge

3 Global water resources and resource use Complementary conceptualisations Green and blue water Virtual water Water footprint Complementary visualisations Global maps (GWSP Digital Atlas) Green water consumption Sankey diagrams Highlight transformations occurring between source, services and sinks Include all water resources and uses in a single diagram Identify roles of different sources in supplying particular services Enable assessment of technical and policy changes (as scenarios) GWSP Digital Water Atlas (2008). Map 63: Green Water Consumption on Cropland (V1.0). Available online at Blue water consumption GWSP Digital Water Atlas (2008). Map 64: Blue Water Consumption on Cropland (V1.0). Available online at

4 Global terrestrial precipitation Figure 1. The allocation of global precipitation Precipitation source services sinks Renewable Fresh Water Resource (RFWR; Oki & Kanae, 2006) Disaggregate amounts by continent, land cover, and usage (service provision) Uses: terrestrial ecosystem services, rain-fed food (60-70% of total water for food; green water), industrial/domestic uses Green water : should this be this direct consumption by crops, or difference cf natural cover? RFWR sustained by precipitation becomes surface and groundwater for further use Source Annual precipitation Services Sinks Terrestrial evaporation/ evapotran Africa ~65,500-70,000 ~20,000 Asia Forests ~27,000 Latin America ~30,000 N.America ~13,500 Oceania ~5,000 Europe ~12,500 Total precipitation on land ~ Wetlands 300 Lakes 2400 Grasslands Cropland Others Ecosystem services Food Others Maximum renewable resources Africa Asia Latin America N.America Oceania Europe Surface water ~28,000 Groundwater recharge ~12,600 RFWR to (Figure 2) Data in km 3 a -1 Doll & Fiedler, 2008 Molden, 2009 Oki & Kanae, 2006 Shiklomanov, 2000 UNESCO, 2012 Vorosmarty et al, 2000

5 Renewable Fresh Water Resource (a) Figure 2 RFWR Again, disaggregate by continent, services; distinguish accessible v inaccessible flows Uses: Environmental services (aquatic ecology), managed flows for agriculture (blue water) Minimum level of environmental flows = c.20-50% of annual runoff; but seasonal variability Sinks: environmental flows to oceans, blue water used consumptively in crop growth Pumped groundwater amounts appear small, but see Fig 3. Recycled water (treated) returns to supply; only 92 km 3 a -1 so opportunities here... but see Fig 4 RFWR in different regions Total applied water Services Post-use treatment Sinks 45-55% of river runoff occurs during periods of flooding ~17,000-20,000. Africa Remote flows Geographically inaccessible ~7,700 Africa Outflow to salt sinks ~30,000-39,000 from rive Surface water from Figure 1 Asia Geographically accessible surface water Asia Environment Aquatic ecosystems ~2,400 from groundwater Hydropower Groundwater from Figure 1 Latin America Groundwater outflow to surface water Latin America North America Agriculture ~2630 Biofuels Food Atmosphere ~1750 Return flows into surface North America Oceania Groundwater Pumping Desalination Oceania Europe Environment Industry ~785 Domestic ~380 Energy ~470 Domestic & Industry ~790 Untreated Wastewater Sewage Treatment Recycled water (direct to Europe Recycling ~92 Groundwater discharge to oceans Min environmental water requirements (approx 20-50% of mean annual runoff) are needed to maintain freshwater ecosystems in fair condition (Smakhtin et al, 2004) Min environmental water requirements (approx 20-50% of mean annual runoff are needed to maintain are needed to maintain

6 Renewable Fresh Water Resource (b) Per capita water use Need data on both total RFWR and per capita water availability Differences between continents, and also within a continent (eg, North Africa is water scarce, with <5% of per capita availability of Africa as a whole).

7 Some issues in global water use Enlarging sections of Figure 2 Fig. 3 Over-use of groundwater Groundwater mining Shallow groundwater extraction leading to wetland decline and loss of ecosystem service Excessive pumping and increasing cost of energy Fig.4 Polluted return flows Small volumes of domestic/industrial return flows, but polluted Much is reused untreated, leading to human health problems and ecological damage A serious water governance problem Treatment requires an energy cost A willingness to use problem Outflow to salt sinks India 190 (+-37) Agriculture return flows Return flows into surface water & percolation into g US 115 (+-14) Groundwater non-renewable China 97(+-14) 283 (+-40) km3 Groundwater ~ Discharge from power plants Recycled water Pakistan 55 (+-7) Iran 53(+-10) Groundwater Untreated domestic & industrial wastewater Organic and inorganic compounds; nitogen and phosphorous Mexico 38(+-4) Saudi Arabia Renewable resources 451 Treated domestic & industrial wastewatersewage treatment High temperature (effect on ecosystems) Industrial effluent (silt and rock particles & surfactants, heavy metals h 21 (+-3) Domestic effluent (extreta, urine & faecal sludge together with grey wa Others 165 Treated water (recycled (reused) or discharged)- wastewater effluent t

8 Effective water management Improving water use efficiency in agriculture Requires integrated land and water strategy Green-blue water distinction doesn t really help with this (cf Jewitt, 2006) Four-fold classification of strategies Managing land v managing water; Managing precipitation v managing RFWR Land management for the effective use of precipitation (Fig 1) Soil management (mulching); improved crop selection and cropping pattern Water management for the effective use of precipitation (Fig 1) Investment in rainwater harvesting and other practices to supplement rainfall Land management for the effective use of RFWR (Fig 2) Agronomic measures; crop selection, pest control Water management for the effective use of RFWR (Fig 2) Investment in improved irrigation technology and practice Managing multiple services: crop production,ecosystem services Terrestrial ecosystems (i) and (iii); Aquatic ecosystems (ii) and (iv)

9 Effective water management

10 Effective water management Managing water resources in the precipitation phase (Fig 1) Interventions (i) and (ii) low technology, agricultural extension Significant consequences because large volumes affected, so efficient/effective measures Source Annual precipitation Services Sinks Terrestrial evaporation/ evapotranspiration Ecosystem services Measure (i) Shifting evaporation to t Wetlands Lakes Measure (i) Importance of terrestrial ecosystems for quality and quantity of water Surface water RFWR to (Figure 2) Food Groundwater recharge Grasslands Cropland Measure (ii) Rainwater harvesting Measure (i) Improvements in soil management, crop selection etc.

11 Effective water management Managing water resources in the RFWR phase (Fig 2) More consideration of/investment in both land phase and water phase Breeding and biotechnology; reduce food waste (food waste = wasted water) Reduce conveyance losses; precision irrigation RFWR in different regions Total applied water Services Post-use treatment Sinks Outflow Measure (iii) : Improvements in land man Surface water from Fig.1 Freshwater ecosystems Groundwater Groundwater outflow to surface water Food Atmosphere from Fig.1 Energy Untreated Wastewater Return flows Groundwater Measure (iv) : Sustainable use of groundwater Recycling Environment Domestic & Industry Recycled water Sewage Treatment Measure (iv) : Multiple use of water through an increase in tre Measure (iv) : Multiple use of water through an increase Measure in treatment (iii): Better & recycling land management for crop production & (iv) managing water for multiple services

12 Calder, I.R., Gosain, A., Rama Mohan Rao, M.S., Bachelor, C., Snehalatha, S., Bishop, E. (2005) FAWPIO-India Progress Report August Forest, Land and Water Policy, Improving Outcomes (FAWPIO) programme. DFID: Forestry Research Programme. Jewitt, G. (2006) Integrating blue and green water flows for water resources management and planning. Physics and Chemistry of the Earth 31, Effective water management More effective management of water and land services A similar idea for integrated management of land and water (and green and blue water)

13 Improved water and land productivity Productivity of land services Improved water productivity leads to improved land productivity

14 Conclusion Sankey diagrams Provide a novel form of visualisation of water resources Global water and its services illustrated in two Sankey diagrams one for direct precipitation (Fig 1), the other for RFWR (Fig 2) A means of refining the blue/green water distinction with realistic link to hydrological process, and better framing for defining management strategies Jewitt (2006): rather than focusing on green or blue water flows, it is the hydrological linkages and their representation in water resources management and planning that needs most attention. Land and water management Increased efficiency of water use requires improved land and water management Land phase strategies - agricultural extension crops, biotechnology, cropping regimes, soil management, reduce food waste, water harvesting Water phase strategies irrigation, new sources reduce conveyance losses, precision irrigation, desalination, more recycling Environmental and ecosystem services Terrestrial (Fig 1) and aquatic (Fig 2) services assessed using the same distinction