<
https://theconversation.com/as-climate-change-warms-rivers-they-are-running-out-of-breath-and-so-could-the-plants-and-animals-they-harbor-213297>
"As climate change warms rivers, they are losing dissolved oxygen from their
water. This process, which is called deoxygenation, was already known to be
occurring in large bodies of water, like oceans and lakes. A study that
colleagues and I just published in
Nature Climate Change shows that it is
happening in rivers as well.
We documented this change using a type of artificial intelligence called a deep
learning model – specifically, a long short-term memory model – to predict
water temperature and oxygen levels. The data that we fed the model included
past records of water temperature and oxygen concentrations in rivers, along
with past weather data and the features of adjoining land – for example,
whether it held cities, farms or forests.
The original water temperatures and oxygen data, however, were measured
sparsely and often in different periods and with different frequency. This made
it challenging before our study to compare across rivers and in different
periods.
Using all of this information from 580 rivers in the U.S. and 216 rivers in
central Europe, our AI program reconstructed day-to-day temperatures and oxygen
levels in those rivers from 1981 to 2019. We also used future climate
projections to predict future water temperature and oxygen levels. This enabled
us to consistently compare past and future river water temperatures and oxygen
levels across hundreds of rivers, which would not have been possible without
using AI.
On average, we found, rivers were warming by 0.29 degrees Fahrenheit (0.16
degrees Celsius) per decade in the U.S. and 0.49 F (0.27 C) per decade in
central Europe. Deoxygenation rates reached as high as 1% to 1.5% loss per
decade. These rates are faster than deoxygenation rates occurring in oceans,
and slower than those in lakes and coastal regions.
Urban rivers are warming up most rapidly, while rivers in agricultural areas
are losing oxygen most rapidly. This could be partly due to nutrient pollution,
which combines with warmer waters to fuel large blooms of algae. When the algae
die and decompose, this process depletes dissolved oxygen in the water."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
