Critical datasets & potential new tools for detection of climate impact on the water cycle

1. Critical datasets & potential new tools for detection of climate impact on the water cycle Dr Stuart Minchin CSIRO

2. Outline • Water as an integrator and amplifier of climate change signals • The attribution challenge • Candidates for measureable signal and new technologies for measurement • CO2 Enrichment • Seasonality shifts • Groundwater and storage • Soil moisture and vegetation trends • Rainfall intensity and atmospheric fluxes • New approaches to communication of climate/water links • Common threads

3. source: Australian Water Resources 2005 Water as an integrator and amplifier of climate change signals • Minimal variations and errors in rainfall and ET estimation accumulate in ground and surface water resource assessment • Streamflow is ~9% of rainfall nation-wide (30 mm/y) • Groundwater recharge <2% of rainfall nation-wide (6 mm/y) • A 10 mm/y change in streamflow can be considered pretty significant in most systems.. • Any change in rainfall is amplified 2 or 3 times in streamflow • Water resources generation and use is very localised • The actual resource is only very partially gauged thus needs to be estimated from sparse obs and indirect information • Keywords: Accuracy, Interpolation, Estimation

4. Percent difference in rainfall and runoff

5. Growing Urban Demand Over-allocation to Irrigation Drying & Warming Climate Expanding Plantations Uncapped Groundwater Extraction Bushfire Recovery Impacts Expanding Farm Dams The Environmental Flows Imperative The Attribution challenge The big 8 water scarcity factors

6. River water resources (MDBSY) • Bringing together different data types • Gauging data • Classification • Water use estimates • River network information Research by Mac Kirby, Albert van Dijk and many others

7. The Attribution challenge is a two way problem Murray Darling Basin: Modelling climate impacts the challenge of mega-data

8. 4 Land Use scenarios Model 1 Model 2 Model 3 Model 15 Model 16 Model 70 Murray Darling Basin Sustainable Yields Project 4 IPCC Scenarios 5 km Gridded Rainfall/Runoff Stochastic Rainfall generation 150 y Security of supply for every demand node in river basin under all 16 scenarios over 150 years

9. Surface and groundwater models used in the 18 MDB reporting regions Warrego IQQM Nebine IQQM Paroo IQQM Lower Balonne IQQM St George SGCS13NT Barwon-Darling IQQM Middle Condamine IQQM Condamine MODFLOW Menindee IQQM Upper Condamine IQQM Bidgee IQQM Border Rivers MODFLOW Lower Bidgee MODFLOW Border Rivers IQQM Moonie IQQM Murray BigMod Lower Gwydir MODFLOW Murray MSM Gwydir IQQM Upper Namoi MODFLOW Eastern Mt Lofty Ranges 6*WATERCRESS Peel IQQM Namoi IQQM Lower Namoi MODFLOW Macq-Castlereagh 6*IQQM Southern Riverine Plains MODFLOW Macquarie MODFLOW Lachlan IQQM Wimmera REALM Mid-Lachlan MODFLOW Lower Lachlan MODFLOW Avoca REALM Daily Snowy SIM_V9 Weekly ACTEW REALM GSM REALM Monthly Ovens REALM Mid Bidgee MODFLOW Upper Bidgee IQQM

12. Lessons from this modelling effort • Transparency • Auditability • Provenance and archiving • Court challenges • In the challenging world of terabyte data

13. Candidates for Measurable Climate Change Signal in the Water Cycle?

14. CO2 Enrichment effects on water cycle • More CO2, better photosynthetic efficiency • Some early projections of higher stream flow due to stomata response in energy limited environments • Much debate about whether observed increases in runoff in some areas are evidence of this • Some emerging evidence of increased Vegetation vigour in water limited environments (much of Australia), consistent with CO2 enrichment prediction • There is a clear role here for continental scale observation of possible CO2 enrichment effects using a combination of RS and in-situ measurement

15. Potential tools: Requires long time-series of consistent remote sensing and stream gauging data Also need ability to correct for local anthropogenic effects (land use, water use, etc) DA-09-03a GlobalLandCover

16. Shifts in seasonality of rainfall • Seasonality shifts predicted due to Climate Change • Impacts of seasonal shifts on water cycle can be enormous (SE Australia an example) • Can be quite spatially variable BUT • Perhaps amenable to low tech measurement? • Date and spatial info perhaps more valuable than precise volume measurement? • A role for crowdsourcing, citizen science or community monitoring efforts in developed and developing world?

17. Groundwater and Soil moisture measurement • Traditionally harder to measure than surface water • Hugely important water sources with often long residence times (meaning trends in recharge can take a long time to see in the water supply) • With surface water drought, reliance on Groundwater grows • There are a number of new techniques available to us for measurement of these factors, but all come with constraints. • Our best chance is combining these observation sources with models to account for partitioning in the water cycle

18. New tools for Groundwater and Soil Moisture • GRACE: Great potential but very low resolution. Integrates deep groundwater, surface water, soil moisture and reservoir storage. Very useful for constraining modelling outcomes • SMOS/SMAP- Both~ 35km resolution 3 day revisit. Direct measure of soil moisture but only surface layer. • Cosmic Ray Soil moisture probes- Integrates soil moisture across medium footprint. Low power requirement, still relatively expensive • Time-series vegetation trends from space: integrates across root zone, CO2 enrichment issue. Large archive already potentially available.

19. Independent calibration of continental ET • Additional constraints on the water balance are needed to improve accounting • GRACE: measures regional, monthly changes in the mass of the earth (i.e. mainly water storage). • Agrees well with model water balance estimates (for the whole MDB). • But how does it verify ET? Research by Albert van Dijk, Luigi Renzullo and others

20. If ET is out we see a bias in storage • It turns out to be a valuable new test of credibility and bias in ET estimates over large scales! • Therefore can also be used as a global constraint in calibration over large scales

21. SMOS/SMAP- Soil Moisture from space • Early results from SMOS promising • Numerous CAL-VAL efforts underway • Continuity may be an issue • Images: ESA and NASA

22. Cosmic Ray Probes

23. Time series vegetation trends for soil moisture

24. Mobile phones for rainfall intensity and flux measurements • Mobile rainfall intensity • Uses degradation in mobile phone signal • Potential for huge international network of rainfall intensity data • Flux tower packages • Cheap sensor packages for deployment on Mobile phone towers? • Potentially huge network for flux measurement • Both need cooperation with mobile phone companies in the private sector http://www.eawag.ch/medien/bulletin/20100126/index_EN

25. The need for communication and visualisation innovation?

26. Google Earth: 4d water visualisation potential

27. Visualisation of climate risk

28. Winning the communication war # 076424868# 076424868 # 076424868

29. Catchment detox

30. Common Threads?

31. Common Threads? • Water is a challenging domain for climate science • Need to combine models, space and in-situ observations to achieve anything in the water domain • Advantages of amplification but many confounding influences cause attribution issues • Standard of evidence more critical (cred.\court action). • Lots of potential for new tools but continuity and historical availability a general issue for most. • Nevertheless a multiple lines of evidence approach and the use of combined observation/modelling systems has promise • Critical that high level impacts are translated and communicated effectively to the local/regional scale

32. Contact Us Phone: 1300 363 400 or +61 3 9545 2176 Email: enquiries@csiro.au Web: www.csiro.au Thank you CSIRO Land and Water Dr. Stuart Minchin Research Director, Environmental Sensing, Prediction and Reporting Phone: 02 62465790 Email: Stuart.Minchin@csiro.au Web: www.csiro.au/clw