Extreme weather and climate change are threatening bridges with collapse

A bridge in Genoa, which partially collapsed during a 2018 storm. Image: Getty.

The recent collapse of a bridge in Grinton, North Yorkshire, raises lots of questions about how prepared we are for these sorts of risks. The bridge, which was due to be on the route of the cycling world championships in September, collapsed after a month’s worth of rain fell in just four hours, causing flash flooding.

Grinton is the latest in a series of such collapses. In 2015, first Storm Eva and then Storm Frank caused flooding which collapsed the 18th century Tadcaster bridge, also in North Yorkshire, and badly damaged the medieval-era Eamont bridge in nearby Cumbria. Floods in 2009 collapsed or severely damaged 29 bridges in Cumbria alone.

With climate change making this sort of intense rainfall more common in future, people are right to wonder whether we’ll see many more such bridge collapses. And if so – which bridges are most at risk?

We know that bridges can collapse for various reasons. Some are simply old and already crumbling. Others fall down because of defective materials or environmental processes such as flooding, corrosion or earthquakes. Bridges have even collapsed after ships crash into them.

Europe’s first major roads and bridges were built by the Romans. This infrastructure developed hugely during the industrial revolution, then much of it was rebuilt and transformed after World War II. But since then, various factors have increased the pressure on bridges and other critical structures.

For instance, when many bridges were first built, traffic mostly consisted of pedestrians, animals and carts – an insignificant load for heavy-weight bridges. Yet over the decades private cars and trucks have got bigger, heavier and faster, while the sheer number of vehicles has massively increased.


Different bridges run different risks

Engineers in many countries think that numerous bridges could have reached the end of their expected life spans (between 50-100 years). However, we do not know which bridges are most at risk. This is because there is no national database or method for identifying structures at risk. Since different types of bridges are sensitive to different failure mechanisms, having awareness of the bridge stock is the first step for an effective risk management of the assets.

In Newcastle, for example, seven bridges over the river Tyne connect the city to the town of Gateshead. These bridges vary in function (pedestrian, road and railway), material (from steel to concrete) and age (17 to 150 years old). The risk and type of failure for each bridge is therefore very different.

Flooding is recognised as a major threat in the UK’s National Risk Register of Civil Emergencies. And though the Met Office’s latest set of climate projections shows an increase in average rainfall in winter and a decrease in average rainfall in summer, rainfall is naturally very variable. Flooding is caused by particularly heavy rain so it is important to look at how the extremes are changing, not just the averages.

Warmer air can hold more moisture and so it is likely that we will see increases in heavy rainfall, like the rain that caused the flash floods at Grinton. High resolution climate models and observational studies also show an intensification of extreme rainfall. This all means that bridge collapse from flooding is more likely in the future.

To reduce future disasters, we need an overview of our infrastructure, including assessments of change of use, ageing and climate change. A national bridge database would enable scientists and engineers to identify and compare risks to bridges across the country, on the basis of threats from climate change.

Maria Pregnolato, Lecturer in Civil Engineering, University of Bristol and Elizabeth Lewis, Lecturer in Computational Hydrology, Newcastle University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

As EU funding is lost, “levelling up” needs investment, not just rhetoric

Oh, well. Image: Getty.

Regional inequality was the foundation of Boris Johnson’s election victory and has since become one of the main focuses of his government. However, the enthusiasm of ministers championing the “levelling up” agenda rings hollow when compared with their inertia in preparing a UK replacement for European structural funding. 

Local government, already bearing the brunt of severe funding cuts, relies on European funding to support projects that boost growth in struggling local economies and help people build skills and find secure work. Now that the UK has withdrawn its EU membership, councils’ concerns over how EU funds will be replaced from 2021 are becoming more pronounced.

Johnson’s government has committed to create a domestic structural funding programme, the UK Shared Prosperity Fund (UKSPF), to replace the European Structural and Investment Fund (ESIF). However, other than pledging that UKSPF will “reduce inequalities between communities”, it has offered few details on how funds will be allocated. A public consultation on UKSPF promised by May’s government in 2018 has yet to materialise.

The government’s continued silence on UKSPF is generating a growing sense of unease among councils, especially after the failure of successive governments to prioritise investment in regional development. Indeed, inequalities within the UK have been allowed to grow so much that the UK’s poorest region by EU standards (West Wales & the Valleys) has a GDP of 68 per cent of the average EU GDP, while the UK’s richest region (Inner London) has a GDP of 614 per cent of the EU average – an intra-national disparity that is unique in Europe. If the UK had remained a member of the EU, its number of ‘less developed’ regions in need of most structural funding support would have increased from two to five in 2021-27: South Yorkshire, Tees Valley & Durham and Lincolnshire joining Cornwall & Isles of Scilly and West Wales & the Valley. Ministers have not given guarantees that any region, whether ‘less developed’ or otherwise, will obtain the same amount of funding under UKSPF to which they would have been entitled under ESIF.


The government is reportedly contemplating changing the Treasury’s fiscal rules so public spending favours programmes that reduce regional inequalities as well as provide value for money, but this alone will not rebalance the economy. A shared prosperity fund like UKSPF has the potential to be the master key that unlocks inclusive growth throughout the country, particularly if it involves less bureaucracy than ESIF and aligns funding more effectively with the priorities of local people. 

In NLGN’s Community Commissioning report, we recommended that this funding should be devolved to communities directly to decide local priorities for the investment. By enabling community ownership of design and administration, the UK government would create an innovative domestic structural funding scheme that promotes inclusion in its process as well as its outcomes.

NLGN’s latest report, Cultivating Local Inclusive Growth: In Practice, highlights the range of policy levers and resources that councils can use to promote inclusive growth in their area. It demonstrates that, through collaboration with communities and cross-sector partners, councils are already doing sterling work to enhance economic and social inclusion. Their efforts could be further enhanced with a fund that learns lessons from ESIF’s successes and flaws: a UKSPF that is easier to access, designed and delivered by local communities, properly funded, and specifically targeted at promoting social and economic inclusion in regions that need it most. “Getting Brexit done” was meant to free up the government’s time to focus once more on pressing domestic priorities. “Getting inclusive growth done” should be at the top of any new to-do list.

Charlotte Morgan is senior researcher at the New Local Government Network.