The Water Footprint Colours of Wine

Transcription

1 Wellington, 11 th November 2016 The Water Footprint Colours of Wine Brent Clothier 1, Steve Green 1, Indika Herath 2, 1 Plant & Food Research,, New Zealand 2 Coconut Research Centre. Sri Lanka

2 Nature s Bounty: Capital & Interest Natural Capital: Our stocks of natural materials & energy Ecosystem Services: The beneficial flows of goods between natural capital stocks, or stocks & humans

3 Intensification we can temporarily exceed the carrying capacity of the earth, but put our natural capital into decline put another way, the ability to accelerate a car that is low on gasoline does not prove the tank is full P. Hawken, A. Lovins & L.H Lovins 1999 Natural Capitalism

4 Non-sustainable groundwater sustaining irrigation: A global assessment Wada et al., Water Resources Research 2012 Irrigation water is from three sources: rain for root water uptake (green water), water from rivers, lakes & renewable groundwater (blue water), and non-sustainable groundwater (dark blue water). Boxes are % unsustainable. Groundwater depletion is a long outstanding issue. [We must] invest in political, institutional & economic efforts to limit the overdraft. It is important to find adaptive responses that do not reduce current food productivity.

5 Supermarkets: Drivers of Sustainability - Urged on by NGOs

6 Three Water-Footprint Colours: Green + Blue + Grey waters Irrigation When blue water is added as irrigation, or frost fighting Evaporation Soil, the green water store captures rainfall, which is transpired, or drained. Soils leach so-called grey water Leaching

7 It seems there s a lot of transpired water in the products we eat & drink

8 The Water Footprint of Marlborough Wine NZ s largest wine region Area: 11,860 ha Soil types: 24 Climate zones: 18 SPASMO modelling: 38-years of weather Functional Unit (FU): 750 ml bottle at the winery gate

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10 The Water Footprint Network s Consumptive Approach T c R T CI -T c R P E s R E SI -E S R E s, irr Lost return flow Irrigated Grapes Consumption Only Blue Water Resource (B)

11 Using the WFN Consumptive Approach (FU = Bottle) Marlborough Stage Blue (L/FU) Green (L/FU) Vineyard Winery Total Snap! That s 118 L per glass

12 The Hydrological Cycle: The Imperative to Consider All Flows ET Full hydrology DR Surface-Groundwater-Surface Connections TRC Receiving Water Bodies Drainage is not lost. It s a vital recharge of groundwater & surface waters

13 Our Hydrological Approach: Correct Connections T c I P P L R I E s I I Irrigated Grapes Full Hydrology D I Blue Water Resource (B) Flows both up (vapour) & down (liquid)

14 Our Hydrological Approach: The Vineyard Blue-Water Footprint Negative blue-water footprints (i.e. groundwater recharge) a reality The blue-water footprint depends on rainfall Regional production-weighted average: -85 L/kg grapes The blue-water footprint needs to account for within-region terroir

15 The Hydrological Blue-Water Footprint for Marlborough Wine Marlborough Vineyard foreground background 1.1 Winery foreground 2.7 background 10.7 Overall, B FP = L/FU That is, every bottle of wine at the winery gate has contributed, on average, nearly 67 litres to Marlborough s groundwaters. Is that sufficient for the ecosystem services sought?

16 Our Fertilized World May, 2013 If we don t watch out, agriculture could destroy our planet. Here s how to grow all the food we need with fewer chemicals. Fertilizer runoff causes toxic algal blooms. This one covered a third of Lake Erie in 2011

17 The Grey-Water Footprint - WF grey WF [ L /( C C )] m n Y Grey = / C m -maximum allowed concentration C n -natural concentration L - load of pollutant Y- grape yield The water required to dilute the leachate to an acceptable standard

18 The Grey-Water Footprint is Related to Soil Type WF [ L /( C C )] m n Y Grey = / C m - NZDWS of 11.3 mg NO 3 -N L -1 C n For Marlborough: 0.31 mg NO 3 -N L -1 L NO 3 -N loading under vineyards (kg NO 3 -N ha -1 ) Y - Grape yield

19 The Grey-Water Footprint for Marlborough Wine Stage Vineyard Winery Total a Not Accounted for System Foreground Background Foreground Background Impact on water quality (grey-wf) L/FU 40.6 NA a Overall, G FP = 44.4 L/FU This seems large. Is it a useful metric? The footprint could be reduced simply by increasing yield, with no environmental benefit!

20 Standard Metrics of Leaching are More Meaningful Every Kiwi drinks 2 litres of groundwater a day! NZ DWS 11.3 mg/l NO3-N (mg/l) Concentration cf. Standards 2 0 Marlborough Loadings for use in the geohydrological modelling of impacts through consideration of exchanges & attenuation Average NO 3 - N loading rate Marlborough 4.9 kg NO 3 -N ha -1 y -1

21 The Spectre of the NPS-FW & it s NOF Nutrient-Loss Regulations by 2025 Our 5.01 mg NO 3 /L is close to the NOF value But the bottom lines are for receiving bodies The rules will be on the land.

22 Water Quality is Linked to Land Management by Leaching ET RF Land management DR TRC Surface-Groundwater-Surface Connections But what is the linkage & attenuation? Receiving Water Bodies

23 200 mm Rootzone 500 mm Fluxmeters 150 mm 50 mm 1000 mm Wick L 600 mm 150 mm The impact of viticulture on groundwater is transmitted to surface water bodies via an aquaclude at Spring Creek Measuring the impact of N leaching on water resources? From vineyard to groundwater downstream

24 Leaching & Groundwater: From Rootzone to Aquifer 1.2 m depth Groundwater 2.4 km downstream Groundwater Velocity m d -1

25 A Simple Model of Lag (Δτ) & Dilution/Attenuation (α) Groundwater (C G ) Leaching (C L ) ANZECC Surface Water Guideline Groundwater lags leaching by 185 days. And the good news the groundwater concentration is just 10% of that leaching. Attenuation & dilution. Enables meeting of the stringent ANZECC trigger of mg/l

26 Other Returns from Vineyard Stocks... Valuable Cultural Services Aesthetic Social relationships Recreational

27 Ecosystem Services Sustaining Returns from Natural Capital Stocks Green Water Stocks Grey Water Stocks Blue Water Stocks