Newsletter #99
Tēnā koutou katoa,
As everyone reading this is aware, following rainfall, braided rivers (try to) rapidly transition from narrow interweaving channels to covering their braidplains with large volumes of water. And you will also be aware that braided river birds and many other species have evolved to adapt to these extremes.
The more a natural braidplain is confined by humans, the less habitat is available for these species. And following rainfall, the harder it is for the rivers to reclaim their braidplains (what we humans call ‘flooding’). Hence, many rivers and their braidplains have been engineered to mitigate the risk of floods impacting us humans and our vast quantities of stuff.
These risk-mitigation structures, like levees, stopbanks, introduced trees, and drainage systems were designed based on projected levels of flooding caused by rainfall. Some (albeit not many) have even been re-engineered to accommodate a changing climate, based in good part on 200-year old thermodynamic principle which states that for every 1°C of warming, the atmosphere can hold about 7% more moisture.
But this thermodynamic principle isn’t working in the real world :
“What we’re seeing is that thunderstorms can likely dump about double or triple that rate – around 14–21% more rain for each degree of warming.” – Dowdy et al, May 2024
This is a global phenomena. Links to research papers and a video at the end if this newsletter help explain. Along with humans and our stuff, our taonga braided river, estuarine, and coastal ecosystems (see slider image below) are at greater risk than many models currently predict. Ultimately, the sooner we give our braided rivers room to move, the better the outcome for all.
Ngā mihi,
Sonny Whitelaw
manager@braid.org.nz
Left 05 March 2025 | Right 06 May 2025.
Image: NASA Earth Observatory Image of the Day – ‘Late-Autumn Storm Lashes New Zealand’
Annual Braided River Seminar
Thanks to the Waitaha Action to Impact Fund and the Department of Conservation contributing funding.
As with 2024, we will be charging a moderate fee of $49.00 to help cover the balance of the costs. Lunch, morning, and afternoon teas are included, and there is plenty of free parking at the venue (map). I look forward to seeing you there. Booking is essential as spaces are limited.
Tarapirohe black-fronted tern workshop
The following day, a Tarapirohe black-fronted tern workshop will be held at Environment Canterbury. The format and duration of this workshop is now being developed. If are interested in attending, please complete this online form.
Bird Surveys
- Orari River: 2023-2024 Bird Survey Data (xls spreadsheet with raw data)
- Ashburton River Mouth: bird monitoring data 2017 to 2025 (xls spreadsheet with raw data)
- Ashburton River Mouth: 2024-2025 bird monitoring report
- Please remember to send me your bird surveys when they are completed. These are added to each of the river pages on the website. This helps researchers and community groups to discern trends over time.
- Please also send a copy to Miles Burford at ECan, as Miles is compiling an amazing database with the aim of eventually making it accessible online through Canterbury Maps.
News/articles
- The Conversation: Rivers are increasingly being given legal rights. Now they need people who will defend these rights in court
- Greenpeace: slams Govt for failure to commit to protecting rivers “…after Parliamentary Under-Secretary for RMA Reform, Simon Court, refused yesterday to commit to upholding Water Conservation Orders, which protect lakes and rivers.”
- DW News (Youtube 45mins): Wind farms in the sea – Opportunity or risk for nature? Excellent coverage of research in the North Sea of the positive and negative impacts of offshore wind turbines on wildlife, including birds, and how risks (from new wind farms, not existing ones) are being reduced as a consequence of the research.
- The Guardian: Study using citizen data finds three-quarters of nearly 500 species in decline, with steepest trend in areas where they once thrived; “The locations where these species were thriving in the past, where the environments were really well suited to birds, are now the places where they are suffering the most,” says ecological statistician and co-author Alison Johnston. “The way I interpret this result is that it’s indicative of major changes in our world.”
- The Conversation: A secret mathematical rule has shaped the beaks of birds and other dinosaurs for 200 million years
- The Conversation: Landmark new research shows how global warming is messing with our rainfall “...the findings pose new challenges for weather and climate predictions, as well as for resilience and adaptation by societies and ecosystems.”
Research & Reports
- Management and monitoring of shorebirds in the Ashley-Rakahuri River during the 2023-24 season
- Ashley Rakahuri February 2025 Operations Report
- Carneiro et al; Typology of the ecological impacts of biological invasions, Trends in Ecology and Evolution 25 April
- Da Silva & Haeter; Super-Clausius–Clapeyron scaling of extreme precipitation explained by shift from stratiform to convective rain type, Nature Geoscience 18 pp382-288 (28 April 2025; open access)
- Wasco et al; A systematic review of climate change science relevant to Australian design flood estimation, Hydrology and Earth Systems Sciences, 28 | 5 pp1251-1285 (15 March 2024; open access)
- Plain English explanation: Dowdy et al; Why are we seeing ‘supercharged thunderstorms’ in Australia? Australian Geographic
- Zhang et al; Anthropogenic amplification of precipitation variability over the past century Science 385 | 6707 pp427-432 (25 July 2024)
