These are known as Ternate Bridges as they cross three rivers at their confluence and form anatural ringroad.这些分叉的桥梁，在他们的三河交汇的地方形成一个天然的环城公路。Like most cases of extreme weather, its severity was due to an unusual confluence of events.如同大多数极端天气情况一样，其严重程度是由数个异常气象条件汇聚在一起造成的。The confluence of those two streams forms a big river.那两条小河汇流而成一条大江。