It’s raining…raining in my hard drive: computer studies map nation’s rainfall risk

Photo: DutchNews.nl

All Dutch cities are expecting extreme rainfall in the next two years – in computer modelling systems at least.

According to the Volkskrant on Thursday, half of the country’s municipalities have already mapped their landscape and exposed it to severe rain, so they know what to do to create ‘climate-proof cities’.

By the end of 2019, the paper writes, the rest will have conducted the same kind of study in order to withstand the effects of climate change predicted by 2050. This involves more extreme rainfall, like the cloudburst that inundated Copenhagen in 2011, but also heat waves and droughts.

Dr Jeroen Kluck, who has created a Water Nuisance Landscape Map system for engineering firm Tauw, told DutchNews.nl that he and his colleagues have examined the water risks for areas including Apeldoorn, Amsterdam, Breda, Den Bosch and Eindhoven.

‘This is being taken very seriously in the Netherlands at the moment,’ he said. ‘About half of the country is yet to be done, and some of them are already hard at work. The municipalities are funding studies – but they must also come up with money for the remediation.’

Coordination

With planning and coordinated thinking this doesn’t involve much extra expense, he argues in his book, Het klimaat past ook in uw straatje.

‘They should marry it with other work, for example if sewage systems need to be removed or the road needs replacing and you then make more room for water too, it doesn’t cost that much more,’ he said. ‘In some places, you can lower the pavements and by not letting water flow into vulnerable places, you can avoid problems.’

Kluck’s analysis shows that most at risk are places with a lot of slopes – rather than where water just spreads over a flat plane – and areas such as Amsterdam canals where homes may sit under the water level.

Municipalities can adjust drains and streets but, he said, people can also slow down the flow of water with things like gardens and water-absorbing green roofs – with the help of local subsidies and advice from initiatives such as Amsterdam Rainproof.




Historic bodies

But, he added, sometimes listed building protection bodies can get in the way of climate-proofing efforts.

‘There are stimulants for green roofs, but they make it difficult when they are for historic buildings,’ he said. ‘On the one hand, municipalities are trying to promote turning flat roofs into green ones, and on the other hand historic protection departments are very concerned with how it looks. It is, of course, a question of them working together.’

Cities are, however, investing money into studies such as his and initiatives like the Amsterdam Project Smart Roof 2.0, a two-year study that aims to investigate and improve evaporation and cooling with a ‘blue-green’ roof.

Meanwhile, innovative companies like brewer De Prael are even diverting rain into products like a beer called ‘heavenly water’.

Hemelswater is beer made from rainwater