Nick van de Giesen

Science for the benefit of people. All people. Worldwide.

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9

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Straight as rain: Africa’s rainfall measured, modelled, mapped, and analysed

In the next few decades, the worldwide demand for food is set to double. Africa and South-America look to be the main producers. But how can large-scale agriculture be achieved if there are no reliable data on the availability of water, when the rain is going to fall, and where? Nick van de Giesen wanted an answer to these questions and that is why he and his colleague John Selker of Oregon State University, U.S.A., founded the Trans-African Hydro-Meteorological Observatory (TAHMO) some eight years ago. Their goal: to establish a network of 20,000 weather stations around Sub-Saharan Africa. Now that the groundwork has been done the first PhD candidate is ready to do the research, supported by the TU Delft Global Research Fellowship.

“It all started in 2007, when I was in the States. I was taking a stroll with John and we were talking about what really needed doing in our field. One of the challenges facing scientists is understanding the water balance in Africa – from a food production point of view, and also because we want to know more about the earth’s climate system in general. It’s scientifically unacceptable that we know so little about what is such a huge part of the world. John and I had both worked in Africa before and we found that one of the major problems is the lack of available data. This was before the smartphone, although we did see a revolution on the horizon in terms of micro-electronics, telephones, sensoring.” One thing that was happening was satellite observation. But rainfall needs to be measured on the ground as well. The satellite may well spot clouds but it will still be unclear if it is raining, and if it is, how much rain is falling. “To improve rain forecasts, satellite data and weather models have to be combined with observations on the ground. That’s when it came to us: if we put up low-cost technology weather stations and accumulate ground data we’d be in business. So TAHMO was conceived during that stroll in 2007. We were very enthusiastic about the project and it didn’t take us very long to sort out what it should look like.”

The start-up phase proved to be a protracted one, however. Van de Giesen and Selker had to pore over business models, import regulations, MOUs – in short, they were two academics getting to grips with the organisation side of things. “It wasn’t until this year, 2015, that we made some real progress. We now have weather stations in Ghana, Kenya and Uganda and fieldwork projects are under way. We hope Nigeria will be next. Researchers there saw what we were doing and have started their own project! Now, for the first time, we are receiving large-scale data – satellite data, weather models and our own measurements on the ground – all of which will be put into a mathematical model by our PhD candidate. We will show that it’s possible to collect data from Africa that are just as reliable as the data we have of the Netherlands.”

After twenty years of fieldwork in Africa Van de Giesen knows like no other that when a project comes to an end so does the infrastructure that supports it. “There is simply not enough money to maintain it. That is why it’s essential for TAHMO to become self-sustaining. Selling data is one way of doing that. We can use the revenue to maintain the network and extend it all over the continent.” In Western Kenya TAHMO is already in partnership with Acre Africa, a company for local insurances for farmers. If there is a period of drought and the farms are within a ten mile radius of a certain weather station, farmers are automatically compensated. “It’s a good example of a working model which helps to increase food production.”

Co-workers: Marjan Kreijns, Rolf Hut, Friso Vos de Wael, Nadine Rodewijk, Els Veenhoven, Boukje Vastbinder, Ellen van Andel, Jos van der Boom, Ali Abbasi and Frank Annor

Global Research Fellowship

Global Challenges
Water and food security, robust and cost-effective weather stations

High-tech Science
Sonic anemometer, drip-counting rain gauge

Co-Creation
Trans-African Hydro-Meteorological Observatory, Oregon State University (U.S.A.) and Decagon Devices Inc. (U.S.A.), IBM, Acre Africa (Kenya)

Story nr.

9

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