Auckland New Zealand floods …. Having spent several days hemmed in by a landslide, Professor John Morgan offers a ‘lesson plan’ for Auckland children returning to school to help them understand what’s going on in their city.
“When Auckland schools go back, there’s a case to be made that geography teachers take over lessons for a day or two. Auckland’s ‘state of emergency’ – the floods and landslides that have affected the city and its region, and which will have consequences for years to come – demand a geographical explanation.
This has happened before. In April 2017 I woke to the sound of trees being snapped by a landslide; that time it was small drain at the top of the slope that couldn’t cope with the water coming from the hills above. When the downpour came, the ground was soddened, and the clay started to slide.
Over the past few days, I have had a lot of time to look at and think about this landscape, and the word that keeps coming to mind is ANTHROPOSCENE, a term coined by geographer David Matless to describe a “landscape emblematic of processes marking the Anthropocene”. The Anthropocene is the term many geologists propose to describe the fact that we live in a new epoch, one in which human activity is changing the Earth’s systems – its climate, its soils, its flow of water and so on. There is controversy about this, it hardly needs saying. Is there water-tight (forgive the pun) evidence that the climate is changing? Is it fair to blame all people (Anthros) when clearly some cause more problems than others? There’s plenty to debate, but what children need when they get back to school is a chance to explore what might be happening to their city in the context of these big processes. The one thing we can say for sure is that this is a human rather than natural disaster.
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The first and obvious question is whether what is happening in Auckland can be attributed to human-induced climate change? Children often think in ‘either/or’ terms, and we could never ‘prove’ that the intense rainfall is a direct effect of a changing climate. But looking at storm frequency and intensity, and abnormal weather patterns across the globe, puts what has happened into context.
Coming down to earth, the next thing is to understand what happens to all that rainfall when it hits the ground. Children are taught early that it ends up in rivers and to the sea, before being recycled into the atmosphere. But we need a more detailed picture of the water cycle. At what rates does water travel through the landscape, and through what pathways? Contrary to the views of one Facebook post, trees don’t cause floods. The opposite: they act as a sponge, soaking up rainfall and releasing it slowly. Different land surfaces and soil types are permeable, pervious or impermeable. What about concrete drives and road surfaces? A key concept is that of ‘antecedent moisture condition’ or the state of the ground before the storms.
Once we have a basic model of the physical geography, we can get into the question of how decisions people have made (in the past as well as the present) are involved in these events. After all, most of us know that removing trees to build houses or building houses on floodplains is not ideal, but why are we compelled to do it anyway? Why, across our city, do we increase housing density by sub-dividing property? Thinking of where I live, why, about 100 years ago, was native vegetation removed for farmland, and why has that farmland since been converted to residential areas?
Starting local invariably leads to wider questions, applicable to other cities and places. How are cities like Auckland encouraged to grow in actual and population size? Is the promotion of Auckland as a global city compatible with the Government’s wellbeing agenda? How ‘liveable’ is our city now? And, most important of all, are there ways to prevent this happening again?
Source : https://www.auckland.ac.nz/en/news/2023/02/07/aucklands-emergency-a-lesson-in-geography.html
