Floods, droughts, and doubts

Patrick Love

Job, in the book of the Bible he gave his name to, was a whiner’s whiner. His version of Happy Birthday includes the catchy lines “May the day of my birth perish and may God above not care about it; may no light shine on it. May gloom and utter darkness claim it once more.” Not a man to see a glass as half full or half empty, for Job it would be smashed on the floor and slice open your foot. So his words on precipitation are pretty much as you’d expect: “If He holds back the waters, there is drought; if He lets them loose, they devastate the land”.

To be fair, that was in the days before governments played “a key role in developing targeted policy responses to market failures that impede the efficient mitigation and allocation of drought and flood risks”, as the OECD Studies on Water report on Mitigating Droughts and Floods in Agriculture puts it. These responses, plus progress in agricultural methods and technology, mean that in most countries, droughts and floods don’t have the terrible impact on economies these days they’d had since biblical times.

In that respect, it’s interesting to look at the findings of Rudolf Brázdil from Masaryk University, Brno, in the Czech Republic and his colleagues in their study of data going back a thousand years on droughts in the Czech Lands. Nearer modern times you get data from instruments, but the earlier chronicles, diaries, tax data and so on describe a series of issues the OECD report talks about, too, such as competition for water resources and the way different impacts can interact. In the Czech case lack of rainfall is often described as not only damaging crops, but also making it impossible for water mills to grind what the farmers did manage to harvest.

It may seem odd taking Europe as an example when there are so many striking (and tragic) cases elsewhere. But one of the surprises for me in the OECD data was the figure below, showing the number and duration of droughts by continent. Europe is similar to Africa, and North America is worse than both of them. But their levels of resilience and vulnerability to risks, whether drought or flood, are very different. The report provides brief summaries of what these different terms mean: risk is the combination of the probability that something will happen and the impacts if it does; vulnerability is the capacity of a system to cope with a risk or combination of risks; and resilience is the system’s ability to recover after a shock.

Number and duration of droughts by continent

Source: based on Shefield, J. et al. (2009).

Intuitively, you’d think that for risks you can’t eliminate, reducing vulnerability is the best policy. It’s not so simple: “Physical and economic interdependencies associated with specific characteristics of water imply there can be synergies and trade-offs in vulnerability reductions across water users and uses” says the report. Lord Smith, Chairman of the UK Environment Agency summed it up in February 2014 after particularly bad floods hit England, pointing out that flood defences cost money and the question was how much the taxpayer should be prepared to spend on different places, communities, and livelihoods. Or, as he put it, “this involves tricky issues of policy and priority: town or country, front rooms or farmland?”.

There can even be trade-offs between shorter and longer term vulnerabilities. Increased irrigation could help farmers cope with a drought, but over time groundwater reserves may be used up and the land become damaged irremediably by erosion and over-exploitation.

Fortunately, there are also ways to make everybody better off, by improving the efficiency with which water is used for instance. Given that agriculture accounts for 44% of the groundwater withdrawn in OECD countries, even relatively small changes by farmers could have a significant impact, although if the water allocation system gives them cheap, plentiful water they would have little or no incentive to change their ways of doing things.

Dams and other hydrological infrastructures could help. The Aswan High Dam for example saved Egypt from the impacts of the droughts and floods that provoked so much misery before it was built, but the OECD report argues that big hydrology projects should complement water policies that try to influence demand rather than replace them. It argues, too, for the need to reconcile environmental, social, and economic objectives (or sustainable development as it’s sometimes called).

Even with all the best policies in place, though, the OECD thinks drought and flood risks are likely to become a growing concern in the future for three reasons: increased population and associated rising demand for food, feed, fibre, and energy in the context of rising competition for water resources and increasing water-related vulnerability; increased demand for flood protection and mitigation for urban areas; and climate change increasing the frequency and magnitude of extreme weather events.

And the report reminds farmers of the need to look after themselves by taking out insurance and not just wait for help, for as Job so rightly pointed out, “Those who are at ease have contempt for misfortune”.

Useful links

OECD Studies on Water

OECD work on risk management in agriculture

OECD Conference on the financial management of flood risk, Paris, 12–13 May 2016

OECD work on disaster risk financing

Originally published at oecdinsights.org on February 17, 2016.

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