Japan's Emperor Naruhito has delivered a keynote speech at a special United Nations' session on water and disasters.

The event was held in New York on Tuesday. The Emperor has long studied issues related to water.

In the 20-minute video speech, he first expressed his condolences to victims of natural disasters that have occurred around the world.

The Emperor then spoke about the waterways in Japan's Edo period, from the 17th to 19th centuries.

The Emperor said Tokugawa Ieyasu, the first shogun of the bakufu administration at the time, and succeeding shoguns utilized water in full to achieve the sustainable development of Edo, now Tokyo.

He added that Ieyasu built a 150 kilometer-long water distribution network, which stretched through the city.
Water flowed into public storage wells through the network for use by people across the city.

He also said transportation of goods through rivers and canals was vital to the development of Edo.

The Emperor said people can learn from the legacy of Edo and meet their common challenges by adopting broader perspectives on the water cycle.

He said, "It is hoped that water, disaster risk reduction, and climate change issues will be fully connected, leading to comprehensive solutions to meet our challenges."

The speech marked the fifth time that the Emperor has addressed the UN water conference, including those dating back to when he was Crown Prince.