The geographer Graham Chapman, who has died aged 70 after a heart attack, applied complexity theory – showing how order and structure can be found in apparently chaotic situations – to problems in south Asia. In the early 1970s, he explored the way farmers in northern India used folklore and local calendars in their decision-making and noted that their knowledge often clashed with that of outside experts. It led him to develop, with colleagues, innovative role-playing games to simulate the experiences of farmers in the developing world, using real data from his field studies and from climate records.
The games enabled his students to experience the fraught nature of decision-making in fragile situations – a more effective approach in understanding issues than using abstract, intellectual methods. Graham recognised the importance of "experiential learning" long before it became fashionable. The Green Revolution Game simulated the experience of the decision-making processes of small farmers in a rice-growing area of Bihar, northern India, at the height of the Asian Green Revolution in the 60s and 70s, and it came to be used all over the world in training. In the 80s, at the request of the World Bank, Graham adapted the Green Revolution Game to simulate a national economy. The result was called Exaction and this was also used extensively in professional training.
Later, he collaborated on the creation of Africulture, which was based on the working lives of farmers in rural Zambia. Playing these games was great fun, especially if Graham was the moderator, but they also taught abiding lessons. Many of us will never forget the experience of being a farmer confronted with uncertainty and the speed with which it is possible to descend into debt.
His games and studies of folklore were both results of Graham's interest in perceptions of the environment. His later research on India's great rivers included critical studies calling into question the popular view that environmental degradation in the Himalayas caused flooding downstream. He also produced a paper born out of his experience of the Bengal floods of 2000, in which he and a colleague, Kalyan Rudra, advocated an "open" policy, recognising that a flood is also a social issue and needs to be addressed through community involvement rather than fixating on engineering solutions.
Water – rainfall and rivers – brought together his interests in complexity and in geopolitics. He contributed, with colleagues at the Centre for Advanced Study at the Norwegian Academy of Science and Letters, Oslo, to a multivolume History of Water, which has yet to be published.
Some of his writing, such as the recent work with mathematicians of the academy, was pitched at a high level of abstraction. But he also rejoiced in writing pieces such as A Short Walk in the Jungle, a personal account of a field trip in India, in which he explored how an outsider and the people he met arrived at various understandings.
Born in Croydon, south London, Graham was the son of Dorothy, a teacher, and Kenneth, a professional philatelist who worked for the firm Stanley Gibbons. From grammar school he went to Cambridge, becoming an academic geographer just as the discipline began making greater use of statistical methods. He quickly took to this quantitative approach, and to computer programming. His PhD was concerned with systems theory. He lectured for a year at Edinburgh University before moving back to Cambridge, as a lecturer and a fellow of Downing College (1969-87). Professorial positions followed at the School of Oriental and African Studies, London (1987-94), and at Lancaster University (1994-2008).
Graham was an adventurous man who revelled in his forays into south Asia, in fell and mountain walking in north-west England, and in many travels in the canoes that he made.
In 1970 he married Anne Gerd. She survives him, as do his son, Nicklas, and daughter, Christina, his five grandchildren, and Winnehl, a refugee from Liberia whom Graham and Anne helped to bring up.
• Graham Peter Chapman, geographer, born 10 June 1944; died 31 August 2014
