Floods and droughts, feasts and famines: the challenge of living with an African climate has always been its variability, from the lush rainforests of the Congo to the extreme dry of the Sahara and Namib deserts. In north western Europe, drizzle and rain is generally spread quite evenly across the year, as anyone who has gone camping in British summer will tell you. But when annual rainfall happens within just a few months or weeks of the year then it is a massive challenge for farmers, towns and industry to access enough water through long dry seasons and to protect themselves and their land from flooding and mudslides when the rains come.
New research suggests that Africa’s aquifers could be the key to managing water better. Professor Richard Taylor at UCL explains: “What we found is that groundwater in tropical regions – and Sub-Saharan Africa in particular – is primarily replenished from intense rainfall events – heavy downpours. This means that aquifers are an essential way of storing the heavy rain from the rainy season for use during the dry season, and for keeping rivers flowing.”
Tropical groundwater may prove to be a climate-resilient source of freshwater in the tropics as intense rainfall favours the replenishment of these resources, according to a new study published in Environmental Research Letters.
Roads can devastate a landscape – scarring it, creating barriers for wildlife and accelerating stormwater so that valuable farmland, habitats and homes get washed away or polluted. What if didn’t have to be that way? What if roads would work with the grain of nature rather than against it?
One of the UPGro teams, lead by Frank van Steenbergen, at Meta Meta Research, has being doing just that. Over the last year, their UPGro Catalyst project has been researching how roads can be used for rainwater harvesting on a landscape scale to recharge aquifers and ponds for later use in the dry seasons.
Working closely with the Mekelle University and the Government of Ethiopia, Frank and his team (including the Institute for Development Studies) has not only been testing the theory but they have been putting into practice. In the region of Tigray, the methods of road design have captured imaginations as well as water and now the government is keen to roll these ideas out further around the country.
The Catalyst project is now complete and a number of resources are now available online:
Question: How can dusty roads provide water? Answer: By harvesting and storing rainwater when it falls on them.
A 30 mm rainfall over a 1-kilometre stretch of road can produce up to 100,000 litres of water. This number points to a huge potential. And not one that has not been adequately tapped (around 7 billion USD are spent on road construction in sub-Saharan Africa alone).
“Roads are generally perceived as infrastructure to deliver transport services, but they are more than that. They are major interventions in the hydrology of areas where they are constructed – concentrating runoff and altering subsurface flows. At present, water-related damage constitutes a major cost factor in road maintenance. Using ongoing research from Ethiopia, this article argues to reverse this and turn water from a foe into a friend and integrate water harvesting with road development.