What is "lingdingyang"

Lingdingyang or Lingding Channel, the middle channel of the Pearl River estuary, it runs from Humen to Jiuzhouyang. The Humen separates Lingdingyang and Shiziyang the upper channel of the Pearl River Estuary in the north and the Jiuzhouyang the lower channel of the Pearl River Estuary at the southern tip of Xiangzhou and the western tip of Lantau all the way till the southern end of the Wanshan Archipelago. Currently, Humen Pearl River Bridge is the only bridge that crosses Lingdingyang at the northern end with Hong Kong–Zhuhai–Macau Bridge a bridge and tunnel across Lingdingyang is being built in the southern end of bay.