An urban heat island is the effect that buildings create on hot days. They absorb a lot of heat and they reflect it out and they re-radiate out and they really heat up the air around them. So, they create this bubble of heat over the city centre that just doesn't disperse in the same way that it would in the countryside.
With climate change we know that extreme heat events are going to get more common even in this country. Our canals and rivers are in many of our main urban areas and big cities so we were interested to find out whether our canals could actually have an impact of reducing these urban heat islands, whether we could deliver urban cooling if you like. So, we partnered with the University of Manchester, who've got lots of expertise in this field, to see what contribution canals could actually make to helping local urban communities.
What we wanted to find out was, do canals help cool urban areas, and can we find a model to test this in different places. We didn't really know; we have a gut feeling - we know we think it helps cooling but we weren't sure how much. So, we created a model that uses physical equations and understanding of heat transfer to make predictions about water temperature and then it was validated by testing actual water temperature in Manchester, Birmingham and London.
The findings were that canals do indeed help with cooling, for up to 100 meters wide and 10 meters tall, up to 1.6 degrees centigrade. When we finally saw the graph and we saw, yes there is that cooling, and it was actually more than we thought, the key thing was there was no cooling in the winter when you don't want it. Also, what we found out was that it really matters how you've got the buildings around the canals and how close and how tall they are, so, yes the canal helps cool, but how we have our building an urban form around the canals makes a big difference as well.
These findings are truly significant and ground-breaking because we now have the evidence, and we have created a model that can show that this canal actually cools down the buildings surrounding it. The potential of this work to change the way that we value things like canals, to design buildings and infrastructure, which really uses is the concept of cooling is huge.
We've done a model which is based on canals, but the potential is for water bodies per se. We can now add another value to that water body.
For people that live or work near canal this will have a big impact on their general comfort, and it'll be much cooler for them during those hot summer days. It can also mean that you don't need to put the air conditioning on. It shows that canals can have this impact without needing to build new infrastructure, without more energy new air conditioning units, as long as we protect the waterways we already have in place.
Research projects like this are important because we know we're facing major climate change challenges, but we can do something about it, and bringing together expertise from different areas, working in partnership with organizations like the Canal & River Trust mean that we can actually think what can we do to make a difference.
The fantastic thing about this particular project is that we're working with MSC students and we're not giving them any restraints, so we're coming up with a hypothesis: do the canals cool urban cities like Manchester? And we're using their expertise, so there was expertise of modeling, there was expertise of planning. Basically allowing them to fly, but giving them guidance in terms of what could the bigger picture be.
The main reason that we started this journey and had the courage to continue this journey was because of Professor Walter Menzies, who was a truly inspirational leader and chaired the Manchester and Pennines Canal & River Trust, and he led us to believe rightly that there's no boundaries in research, and that we should take joy in working in partnerships and with working with the wonderful talent within this great city of Manchester.
It's really exciting to be part of this research. The next step for us and the experts at the University of Manchester is clearly to do further work on what sort of design elements need to be built into canalside buildings in the future. New buildings are going up all the time and it's important that as we build new structures we're making them future-proof and making them deliver the best benefit that they can.
One of the really good things about working for an organisation like the Canal & River Trust is that we've got this 200-year-old historic estate, but it's delivering benefits that really matter to people now and in the future. It proves our waterways have a role to play in helping local communities in our urban areas and further afield in fighting the impacts of climate change, and we're looking forward to doing further research in lots of other areas as well.
