‘The volcano is erupting again, but it's OK...' Active volcanoes don't tend to feature on UK local government risk registers, but in Kagoshima Prefecture in South West Japan, they have learned to live with Sakurajima, one of the country's most active peaks.

Every summer the citizens of Kagoshima City put up their umbrellas, not to protect against rain – the prefecture is one of the wettest and balmiest in the archipelago – but against the ash that the stratovolcano spews out covering the city streets in fine grey powder.