As part of the government funded science challenges, Water New Zealand has been invited to participate in “Deep South Science Challenge” dialogue on drought. The outcomes of the dialogue will be funded research projects that look at the Impacts and Implications of climate projections of drought.
Impacts and Implications projects will build on improved understanding of future climate and existing initiatives developed by NIWA;
- A drought monitor system for keeping track of drought conditions across New Zealand
- Potential evapotranspiration deficit (PED) projections available in Section 3.8 of the Ministry for Environment Climate Change Projections for New Zealand
Scientists noted that projections of soil moisture and drought remain relatively uncertain compared to other aspects of the water cycle. Nonetheless, a major message is that drought severity increases over time, and the extent will be influenced by the extent of future greenhouse gas emissions. Key takeaways from NIWA were:
- Drought risk is expected to increase this century in already drought-prone areas,
- ‘Severe droughts’ occur more often by mid and late-century and worsen as greenhouse gas forcing increases
- Low flow conditions are expected to be reached earlier in the water year for much of the North Island and eastern South Island, increasingly so with higher radiative forcing scenarios and towards the end of the century (except the West Coast)
- Summer Mean conditions during spring, summer and autumn seasons are expected to remain about the same or become slightly wetter by mid-century for the lowest radiative forcing scenario. With increased radiative forcing and time, soil moisture conditions are expected to become drier in the North Island and in South Canterbury, Otago and Southland.
- Soil Moisture Deficit conditions during summer are expected to remain about the same or become slightly lower by mid-century. With increased radiative forcing and time, soil moisture deficit conditions are expected to increase in the North Island while reducing in South Canterbury, Otago and Southland.
- Less stream water will be available during summer months, and that there is likely a potential reduction of agricultural/plant water needs in the summer months in South Island versus an increase in the North Island.
The projects will complement existing water related research projects being undertake as part of the challenge;
- Impact of climate change on New Zealand’s frozen water resources (A Mackintosh)
- Robust adaptation decision-making under uncertainty in the water sector (A Wreford)
- National hydrological and water resource impacts of climate change (C Zammit)
- Drinking water in Te Hika o te Iku (Northland) (W Henwood)
Members with an interest in existing research streams, or feedback on research priorities for the upcoming funding round should contact: Lesley.firstname.lastname@example.org. Priorities for future research will be developed at a workshop on 12th June.