BBC: Coping with increased risk of flooding in a changed climate is not just about money. BBC environment correspondent Matt McGrath reports from Japan, where philosophy is just as important as resources.
At a large government research facility in Tsukuba city, engineers have built a 30-sq-m replica of a meandering Japanese river.
At one point along the concrete shore, there's an unremarkable, small square of wood, with red and white triangles on top. But it is a constant reminder of the power of...