‘The HYDE-portal makes the history of land use both accessible and visible’

Kees Klein Goldewijk
Dr. Kees Klein Goldewijk. Photo: PhotoA

In this series of interviews we show what contribution projects can make to FAIR research IT. The research teams of the projects have received a grant from the FAIR Research IT Innovation Fund.

The History Database of the Global Environment (HYDE) provides global data on population and land use over the past 12,000 years. Through the HYDE portal, that recently went online, you can easily and specifically retrieve data from this database. You can also visualise and download this data interactively. What is the story behind this tool? Founder of this tool Kees Klein Goldewijk explains.

Suppose you are doing research into biodiversity in 17th-century South-America and you want to know more about how agriculture developed in those parts at the time. Or you want your students to analyse how the spread of humanity is connected to climate change. Wouldn’t it be great it if you could easily search for and download this data yourself? And what if you could even visualise these developments with interactive graphs and maps? The HYDE portal makes it all possible. This tool makes data from HYDE available for reuse in a structured and replicable way, both for scientists and the general public. HYDE is regarded as the most up-to-date, most comprehensive and most widely used reconstruction model for long-term historical land use.

The current times ask for reflection. For example, do we still want that steak from Argentina, or soya from there for the pigs here?

HYDE: a life’s work

First some context about HYDE itself. This database evolved over many years, says Klein Goldewijk.“I have been in this business since the early 1990s; first at the environmental section of the RIVM (National Institute for Public Health and the Environment), later at the Netherlands Environmental Assessment Agency. There I was involved in integrated assessment modeling around climate change. I made population and land use maps which are used for the IMAGE model.” These maps formed the basis for his ever-growing database. Over the years, he took the data to various employers, until he finally, also a PhD research further on, ended up at the Copernicus Institute of Sustainable Development of the Faculty of Geosciences. Here he is still working on his database. `I have kept building HYDE. I went further back in time, improved the resolution and added indicators.”

Copernicus Land Change Lab

One theme within the Copernicus Institute is Sustainable land. Researchers deal with land and land use, such as biofuels, biodiversity and sustainable agriculture. Klein Goldewijk falls under the section Environmental Sciences and has placed his activities in the ‘Copernicus Land Change Lab.’ “It is not an official research group, rather a signboard. A recognisable name helps to show people what you are researching.”

Collecting data

HYDE shows how population and agriculture have developed over time. How do you figure out such things? “Nowadays you have satellites and statistical agencies. For instance, I use a lot of census data from countries. But further back in time, that data is unreliable or absent. That is why I work with assumptions. If you know approximately how many people lived somewhere, you can estimate how much farmland they needed. You can also analyse: where is that agriculture likely to be if you look at topography, water availability, climate? You have to think logically. I do so in collaboration with historians, archeologists and paleo-ecologists. In the end the data give an order of magnitued. That is enough for climate models, for instance. Other researchers look at the impact of changing agriculture on biodiversity loss. You can link it to so many things. That is why HYDE is used around the world by all kinds of bodies, such as the Global Carbon Project.

Thanks to the HYDE portal, many more journalists and other interested parties can use the data.”


Klein Goldewijk is trying to make his data available to everybody. “I am the only one who has created such a database, at least on a global scale and this far back in time. That is why it is highly in demand. At first I could only make my data available in a fairly technical manner, to fellow scientists, via Yoda. But for that you need certain (technical) expertise, because those data are in a certain format. And you have to download everything, and the files are huge. So not everybody can work with the data in that way.” So the number of requests was increasing, not only from scientists but also from journalists, secondary school pupils, students. “They asked: I only want to look at one country, or one indicator, could you please provide the data? In itself, yes,  but it involves a lot of work. So I was reluctant to do that. I thought: surely there must be a better way? That is how the idea for the portal was born.”

The power of the portal

With the help of the HYDE tool you can query the data online in a user-friendly way. “That is the power of this portal. You can look at a single country or period, compare certain countries or periods, create graphs, select indicators such as population density, arable farming, pasture or rice cultivation. You can also download the data you want: the spatial maps or graphs.’ So plenty of options. That makes the HYDE portal interesting for a wide audience. “Of course fellow researchers can use it, alongside the Yoda route. But also keep journalists in mind writing about a certain country or period. Earlier on my data was used in  National Geographic magazine and for a documentary by Sir David Attenborough. But then: those teams had the manpower and expertise to work with my data. Thanks to the HYDE portal many more journalists can make use of it.” It is also of interest to students and secondary school pupils. “For instance, this tool can visualize wave movements through time visible. For instance, Europe was almost completely deforested after the Late Middle Ages, what we are trying to plant back now. And think of the colonisation of North-America and the associated changes in agricultural use.”

Kees Klein Goldewijk
Kees Klein Goldewijk. Photo: PhotoA

Wider impact

Klein Goldewijk also hopes that the tool helps raise awareness. “The current times call for reflection. Do we still want that steak from Argentinia or soya from over there for the pigs here? Behind that one product you buy there is a whole story, an ecological footprint. My data can illustrate that story. I make animations, for instance, that show how agriculture has spread like an oil slick around the globe. This helps people realise: there is a lot of agriculture around the world, but there is a link to my local supermarket.” The geoscientist does not want to impose anything on people, but does want to make them think. “I want to provide insight into what we are doing collectively. From that insight we can choose: do we continue as we are now or can we farm in other ways? And what if we change our diet? Cattle farming in particular needs a lot of water and space, so eating less meat would help tremendously. The HYDE portal can help with both substantiation and creating awareness around social issues.”

The HYDE portal can help with both substantiation and creating awareness surrounding societal questions.’

Virtual gaming

The FAIR Research IT Innovation Fund was of great value for this project, says the researcher. “I did not have the time nor the knowledge to develop a portal. Thanks to this fund, I was able to  hire a smart student who figured out how he could make the portal in a technical sense and then set it up with a designer. The funds was a huge help. I am very grateful that it is there.” Thanks to a financial windfall, new ideas are brewing.  “In the end, I did not need to buy a server, but could use an internal server. Our working student worked two days a week, fewer hours than estimated beforehand. The resulting budget space the FAIR project manager allowed me to use for something else. That is why I am now looking into what we can do with virtual reality or augmented learning in cooperation with a virtual gaming company. This will allow us to visualise this data even better. Or maybe we will develop an educational game for school pupils or students.”

Taking data further

One thing is clear: the inspired researcher wants to take his data further, both inside and outside science. “I am always looking for ways to do more with the data in a fun and accessible way. Outreach is also promoted within Utrecht University, showing the public what you do. And the university promotes open access and working FAIR.” The HYDE portal certainly contributes to working FAIR. It makes existing data better findable. It also makes data more accessible: without technical knowledge, people can search for and download data. Moreover, they can reuse the data for all kinds of new research and other purposes.

The HYDE project itself was also set up in a FAIR way. “We have documented everything: how do you build such a portal? That way others have a manual and even more people benefit from this project.” Working FAIR is on the agenda of the Copernicus Institute anyway, according to the researcher. “This is how we create a central gathering space for research projects, so that we can make better use of each other’s scientific efforts.I am very much in favour of collaboration in science. I always say: let’s share as much as we can, and build from there.”


About the FAIR Research IT Innovation Fund

Utrecht University wants each research team to be well supported in the field of research IT. One of the ways to achieve this is through the FAIR Research IT Innovation Fund. Scientists have received a grant for projects which, for instance, improve the IT infrastructure of scientific research. You may think of projects that enable enough storage capacity for data, or of the development of tools and services that help researchers in their work. FAIR and open science principles are the guidelines when selecting projects. Other researchers must be able to easily and quickly reuse the knowledge and solutions. Do not hesitate to contact the fund if you have any questions.