Japanese flood control expert Yutaka Takahashi, and American and French gene therapy scientists received the 2015 Japan Prize at a ceremony in the presence of Emperor Akihito and Empress Michiko in Tokyo on Thursday.

The Japan Prize Foundation awards the annual prize to those who have contributed to the development of science and technology.

Takahashi, 88, received the prize for his contribution to river basin management and the reduction of water-related disasters in Japan and other countries.

"I am convinced that we in river-disaster research should review the history of each river and try to conduct integral water control from upstream to downstream, the mouth and the coast," he said in a speech at the ceremony. "I thank you for appreciating my efforts."

American Theodore Friedmann, 79, and Frenchman Alain Fischer, 65, were joint prizewinners in the field of medical and medicinal science for their proposal of the concept of gene therapy and clinical applications.

Friedmann, a pediatrics professor at the University of California, San Diego, proposed the concept of gene therapy during the 1970s. Fischer, a professor at College de France, was the first to prove its effectiveness clinically.