Population, land prices, hospitals, evacuation sites... By overlaying various data related to daily life onto a map, one can visualize "what is happening where". Disparate data are linked using location information as a clue, revealing relationships and social structures that were not visible through numbers and tables alone. This is the great power of GIS.

A symbolic example of this power is the episode in 1854 when physician John Snow investigated a cholera outbreak in London's Soho district. Snow examined a map plotting death cases and, based on death records and interviews with residents, revealed that deaths were concentrated around the public water pump on Broad Street. Using spatial visualization as a clue, he approached the source of the cholera outbreak, which was still being debated at the time.

"No matter how much data exists in the form of text or numbers, putting it into a visualization—that is, a 'map'—is highly significant for providing direct inspiration to the human brain."

The perspective of "seeing through space" that Professor Kawabata speaks of may significantly change how we view everyday problems.

For example, in a joint study published by Professor Kawabata and Professor Yukiko Abe (Hokkaido University) in 2018, a trend was shown on a map within the Tokyo metropolitan area where regions with long commute times for men overlapped with regions where labor participation rates and regular employment rates for married women raising children were low.

"For households raising children, especially for women, long-distance commuting becomes a major time constraint. I felt a great sense of accomplishment as a researcher that the structure of the work-residence mismatch, which was intuitively thought to be 'likely true', was visualized as data using GIS methods".

In 2021, in a joint study published by Professor Kawabata, Professor Abe, and Mr. Yuki Shibatsuji, they analyzed the spatial concentration of children in single-mother households in Japan, which has a high poverty risk among OECD (Organisation for Economic Co-operation and Development) member countries. Using municipal data from across the country, it became clear that children in single-mother households are concentrated in specific regions, mainly in Hokkaido and Western Japan. "We also saw correlations with regional characteristics such as low income and population outflow. Poverty risk can be understood in connection with regional structures. This was a study unique to GIS."

Commute times and employment rates, poverty risk and regional characteristics. Problems that seem separate at first glance can be seen as spatial patterns by capturing them through the common axis of "location". GIS is a foundational technology for visualizing these invisible connections and understanding social issues from a new perspective. The insights gained from it serve as clues for thinking about new policies and the nature of cities.

While GIS is now widely used as one of the primary methods in data science, in 1990s Japan, its use was limited to a few fields such as geography and urban planning. How did Professor Kawabata encounter GIS?

"I was interested in economics and finance and studied financial policy, but I entered the job market during the 'employment ice age'. I decided to go to the Graduate School of Media and Governance at SFC (Shonan Fujisawa Campus) just to acquire a practical skill."

She entered the Architecture and Urban Design Program, which grants eligibility to take the first-class architect exam upon completion. However, halfway through, she realized, "I don't have a sense for architecture, and I thought there would be no path forward if I continued like this." At that time, there was an opportunity to conduct research jointly with the neighboring GIS laboratory. Even at a time when the internet was not yet widely available, SFC had a cutting-edge environment.

She digitized land-use maps from the Edo period and overlaid them with location information for temples and shrines. Instantly, the concentration of temples and shrines in specific areas was visualized on the map. "It was a series of fresh surprises, like throwing data into a magic box and having results I'd never seen before appear in front of me." She became so absorbed in GIS that she even assembled computer parts herself to increase processing speeds.

That interest opened a path, leading her to the doctoral program at the Massachusetts Institute of Technology (MIT), where she joined the GIS group in the urban planning department. The theme she tackled was the spatial mismatch between place of residence and employment opportunities, known in academia as "spatial mismatch". This issue related to urban inequality had garnered high interest in the fields of economics and urban planning, and a vast amount of research had already been accumulated.

Professor Kawabata used GIS to analyze the accessibility gap to employment opportunities caused by differences in place of residence and means of transportation. Furthermore, she examined the relationship between employment accessibility and the employment status of workers placed in disadvantageous conditions. She applied GIS, which was still a new analytical method at the time, to this research area with its vast accumulation of studies, attempting to capture urban inequality in a verifiable way.

In 2002, this research was highly acclaimed, receiving the Outstanding Ph.D. Dissertation Award from the MIT Department of Urban Studies and Planning, as well as being recognized as the best doctoral dissertation in the field of urban planning across the United States. The MIT Ph.D. diploma bears the words, "IN RECOGNITION OF SCIENTIFIC ATTAINMENTS AND THE ABILITY TO CARRY ON ORIGINAL RESEARCH". Professor Kawabata took those words to heart—recognizing scientific achievement and the ability to continue original research—and has continued her research ever since.

She returned to Japan after five years of study abroad, but at the time, the use of GIS was still limited in both academic societies and practical fields in Japan, making the job search difficult. In the midst of this, it was Atsuyuki Okabe, then Director of the Center for Spatial Information Science (CSIS) at the University of Tokyo, who reached out to her.

Initially an unpaid researcher, she was soon hired as an institutional researcher (postdoc) at CSIS. In 2005, she became the first Japanese person to obtain the "GIS Professional" certification accredited by the U.S. GIS Certification Institute.

"In Japan, there were still few appropriate textbooks for learning GIS systematically, so I conducted classes while gathering materials from all over." When she took up her post as an associate professor at the Keio University Faculty of Economics in 2012, she set about writing an introductory series of textbooks herself.

Professor Kawabata emphasizes education that makes students "think" rather than just "teaching" them.

For example, in an open seminar for second-year students, she has students think about everything from the concept and target audience to the reasons for the location under the theme of "Where would you open a hamburger shop?" GIS is increasingly used in practice for trade area analysis and other applications, making this learning connected to real-world challenges.

In seminars for third and fourth-year students, the theme setting is also student-led. "Outputs thought up by students themselves are overwhelmingly better than those produced under detailed guidance. Sometimes I, who have been involved with GIS for over 30 years, am taught new ways to use it by students who have just started learning. It is truly 'learning while teaching, teaching while learning' (*)."

GIS is now utilized in many aspects of our lives, and we enjoy its benefits without even realizing it. The cluster maps released during the spread of COVID-19 are one such example. Professor Kawabata says she never imagined a society where it would be used so naturally would arrive.

"One of the triggers for GIS gaining attention was the 1995 Great Hanshin-Awaji Earthquake. Until then, there were many situations where information was grasped by comparing paper maps and individual documents. However, using GIS, aerial photographs, road networks, and damage information can be overlaid on a map. It became easier to grasp the damage situation and the routes necessary for support and recovery, and the effectiveness of GIS became widely recognized."

In 2007, the Basic Act on the Advancement of Utilizing Geospatial Information was enacted, establishing a systemic framework. However, at first, the available data and utilization environment were insufficient, and widespread adoption still took time. Things began to move significantly in the 2010s.

"The preparation and release of data held by the national and local governments progressed, and the amount of usable data increased all at once. For example, the PLATEAU 3D city models, led by the Ministry of Land, Infrastructure, Transport and Tourism, are data that represent urban information such as buildings and land use in three dimensions, and I use them in my classes", says Professor Kawabata.

Furthermore, the evolution of tools supported widespread adoption. GIS, which once required specialized operations, now has environments where it can be handled intuitively, and services available on the web are expanding.

Coupled with these advancements in data and technology, GIS has become an indispensable information infrastructure for society. "From the 2022 academic year, 'Geography' became a compulsory subject in high schools, and all high school students now learn geographical skills related to maps and GIS. The environment for utilization is ready, but there are still not enough people who can master it. Human resource development is becoming increasingly important."

How will the next generation master GIS and what kind of future will they draw? Amid expanding possibilities, Professor Kawabata is currently interested in "GeoAI".

"GeoAI, which combines geospatial information and AI, has been spreading rapidly recently, and I find it very interesting." By utilizing GeoAI, one can predict disaster risks and changes in cities and regions, or when problems arise, quickly grasp the situation and obtain clues for comprehensively considering responses based on various information.

Furthermore, she has high expectations for high-precision 3D geospatial information, such as 3D city models and 3D point cloud data, as game changers.

A 3D city model is geospatial data that reproduces various elements constituting urban space, such as buildings and roads, in three dimensions and links them with attribute information such as usage and structure. It serves as a clue for quantitatively grasping the location, height, shape, and usage of buildings, as well as the three-dimensional structure of roads and transportation facilities. For example, it can be utilized for analyses that capture urban space three-dimensionally, such as inundation risk assumptions, urban planning, and disaster prevention.

On the other hand, 3D point cloud data is data that records terrain, structures, trees, etc., as a collection of countless points including height information. It allows for a detailed and three-dimensional capture of real space, such as the fine shapes of buildings, terrain undulations, and the height and spread of vegetation.

For example, in the large-scale debris flow disaster that occurred in Atami City, Shizuoka Prefecture in 2021, by overlaying 3D point cloud data from before and after the event, it was possible to quantitatively compare and grasp the extent of the collapsed embankment and the status of sediment outflow.

PLATEAU 3D city models and 3D point cloud data released by Shizuoka Prefecture and others can be downloaded and used as open data from the G-Spatial Information Center and elsewhere. Professor Kawabata is interested in using such high-precision 3D geospatial information to analyze various urban issues more three-dimensionally.

Abundant open data and the evolution of tools. New analytical techniques and the accumulation of years of insight. As these elements overlap, Professor Kawabata's research is moving toward a stage of drawing a "future blueprint" that not only deciphers the current state of cities but also envisions safer and more sustainable cities and regions.

Composition: Toru Tamakawa, Editor-in-Chief of Asahi Shimbun GLOBE+

Interview/Text: Maiko Watanabe

Photography: Hidehiro Yamada