Here's an imaginary tube map of Leeds

A detail from Rich Daley's Leeds Tube map.

What do you do when you move to a new city that doesn't have its own metro network? Easy: you invent one.

That, at least, is what Rich Daley did, when he moved to Leeds in 2010. "I'm a huge fan of the metro systems in cities like London, Paris and Berlin," he told CityMetric. "They’re so entrenched in the public consciousness that you think of parts of the city in terms of their locations on the metro map,  rather than their location in reality."

Leeds, though, has no such system to provide a mental map (the government spent £40m planning the modestly-named Leeds Supertram system before cancelling it in 2005). So Daley decided to invent his own, "to provide the same kind of mnemonic" as the London Underground map. It worked, too: "I regularly find myself thinking about where or how to get to parts of the city in terms of the Tube Map."

You can see a detail of the map, showing Leeds city centre, above. To see the whole thing, click on the map below.

How did you decide where the routes should go?

A lot of staring at Google Satellite view to work out where the population centres were and how to link them together. Most of the stations are located in these kinds of organically occurring hubs where shops and services appear. After that I got a lot of feedback on Twitter and connected some places up that weren't on there before. People are still very passionate about how the fictional Tube should look!

Leeds is part of a bigger conurbation, including Bradford, Huddersfield, Wakefield... Why aren’t they on the map?

I wanted to start with Leeds since that's where I live, and maybe work outwards. The Leeds-Bradford line was the first attempt at this, connecting the airport and the Tube network with Shipley station, which functions as a kind of hub for the Bradford borough.

Since Gordon Brown's time there's been talk of something called (awful name) the "Leeds City Region", which places the city in the middle of a larger megalopolis of nine boroughs, rather like Manhattan is in New York City. I like the idea but I'd call it something like the Aire & Calder Metropolis myself – else you'd never get people in Bradford, York and Wakefield on board.


What's the city's real transport network like?

We are basically still in the dark ages. Most routes are only accessible by buses, which are controlled almost exclusively by FirstBus's virtual monopoly.

The local rail network is really good, but provides connections only to very specific parts of Leeds and West Yorkshire: most of the pre-Beeching lines haven't been built on, but the stations are long gone. Leeds City Station itself is one of the busiest stations in Britain outside London, and it simply can't cope with the number of passengers: the Manchester-Salford central zone, by contrast, has five, not including all the tram stations.

There's a big plan for something called NGT ("New generation Transport") in the next few years. It's  a trolleybus with just one line, and it's met opposition from all sides. The right says it’s a waste of money and will clog up Otley Road; the left says it's a glorified bus. The public inquiry has been going on for months and months.

So is this the map finished?

This is version 3: I keep updating it either as I discover more about the city, or someone alerts me to an area I haven't served well. Look at the map now, I realise that it says “Leeds Metropolitan University” when that's now “Leeds Beckett University”, and it also fails to include the forthcoming HS2 New Lane Station. So maybe there'll be a v4 soon.

Spotted a fantasy tube map of your own city? Whiling away the hours drawing your own, and now ready to show the world? Drop us a line.

 
 
 
 

The risk of ‘cascading’ natural disasters is rising

A man watches wildfires in California, 2013. Image: Getty.

In a warming world, the dangers from natural disasters are changing. In a recent commentary, we identified a number of costly and deadly catastrophes that point to an increase in the risk of “cascading” events – ones that intensify the impacts of natural hazards and turn them into disasters.

Multiple hazardous events are considered cascading when they act as a series of toppling dominoes, such as flooding and landslides that occur after rain over wildfires. Cascading events may begin in small areas but can intensify and spread to influence larger areas.

This rising risk means decision-makers, urban planners and risk analysts, civil engineers like us and other stakeholders need to invest more time and effort in tracking connections between natural hazards, including hurricanes, wildfires, extreme rainfall, snowmelt, debris flow, and drought, under a changing climate.

Cascading disasters

Since 1980 to January 2018, natural disasters caused an inflation-adjusted $1,537.4bn in damages in the United States.

The loss of life in that period – nearly 10,000 deaths – has been mounting as well. The United States has seen more billion-dollar natural disaster events recently than ever before, with climate models projecting an increase in intensity and frequency of these events in the future. In 2017 alone, natural disasters resulted in $306bn losses, setting the costliest disaster year on record.

We decided it was important to better understand cascading and compound disasters because the impacts of climate change can often lead to coupled events instead of isolated ones. The United Nations Office for Disaster Risk Reduction, or UNISDR, claims: “Any disaster entails a potentially compounding process, whereby one event precipitates another.”

For example, deforestation and flooding often occur together. When vegetation is removed, top soil washes away and the earth is incapable of absorbing rainfall. The 2004 Haiti flood that killed more than 800 people and left many missing is an example of this type of cascading event. The citizens of the poverty-stricken country destroyed more than 98 per cent of its forests to provide charcoal for cooking. When Tropical Storm Jeanne hit, there was no way for the soil to absorb the rainfall. To further complicate existing issues, trees excrete water vapor into the air, and so a sparser tree cover often yields less rain. As a result, the water table may drop, making farming, which is the backbone of Haiti’s economy, more challenging.


Rising risk from climate change

Coupled weather events are becoming more common and severe as the earth warms. Droughts and heatwaves are a coupled result of global warming. As droughts lead to dry soils, the surface warms since the sun’s heat cannot be released as evaporation. In the United States, week-long heatwaves that occur simultaneously with periods of drought are twice as likely to happen now as in the 1970s.

Also, the severity of these cascading weather events worsens in a warming world. Drought-stricken areas become more vulnerable to wildfires. And snow and ice are melting earlier, which is altering the timing of runoff. This has a direct relationship with the fact that the fire season across the globe has extended by 20 per cent since the 1980s. Earlier snowmelt increases the chance of low flows in the dry season and can make forests and vegetation more vulnerable to fires.

These links spread further as wildfires occur at elevations never imagined before. As fires destroy the forest canopy on high mountain ranges, the way snow accumulates is altered. Snow melts faster since soot deposited on the snow absorbs heat. Similarly, as drought dust is released, snow melts at a higher rate as has been seen in the Upper Colorado River Basin.

Fluctuations in temperature and other climatic patterns can harm or challenge the already crumbling infrastructure in the United States: the average age of the nation’s dams and levees is over 50 years. The deisgn of these aging systems did not account for the effects of cascading events and changes in the patterns of extreme events due to climate change. What might normally be a minor event can become a major cause for concern such as when an unexpected amount of melt water triggers debris flows over burned land.

There are several other examples of cascading disasters. In July, a deadly wildfire raged through Athens killing 99 people. During the same month on the other side of the world in Mendocino, California, more than 1,800 square kilometers were scorched. For scale, this area is larger than the entire city of Los Angeles.

When landscapes are charred during wildfires, they become more vulnerable to landslides and flooding. In January of this year, a debris flow event in Montecito, California killed 21 people and injured more than 160. Just one month before the landslide, the soil on the town’s steep slopes were destabilised in a wildfire. After a storm brought torrential downpours, a 5-meter high wave of mud, tree branches and boulders swept down the slopes and into people’s homes.

Hurricanes also can trigger cascading hazards over large areas. For example, significant damages to trees and loss of vegetation due to a hurricane increase the chance of landslides and flooding, as reported in Japan in 2004.

Future steps

Most research and practical risk studies focus on estimating the likelihood of different individual extreme events such as hurricanes, floods and droughts. It is often difficult to describe the risk of interconnected events especially when the events are not physically dependent. For example, two physically independent events, such as wildfire and next season’s rainfall, are related only by how fire later raises the chances of landslide and flooding.

As civil engineers, we see a need to be able to better understand the overall severity of these cascading disasters and their impacts on communities and the built environment. The need is more pronounced considering the fact that much of the nation’s critical infrastructure is aged and currently operate under rather marginal conditions.

A first step in solving the problem is gaining a better understanding of how severe these cascading events can be and the relationship each occurrence has with one another. We also need reliable methods for risk assessment. And a universal framework for addressing cascading disasters still needs to be developed.

A global system that can predict the interactions between natural and built environments could save millions of lives and billions of dollars. Most importantly, community outreach and public education must be prioritised, to raise awareness of the potential risks cascading hazards can cause.

The Conversation

Farshid Vahedifard, CEE Advisory Board Endowed Professor and Associate Professor of Civil and Environmental Engineering, Mississippi State University and Amir AghaKouchak, Associate Professor of Civil & Environmental Engineering, University of California, Irvine.

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