Changlu is not first of all a place but a kind of ground. The name appears earliest in the Water Classic and its commentary, given because the shore there was thick with reeds beside the water. Its old range ran the whole Bohai coast, from Shanhaiguan in the north to the Yellow River mouth in the south. The seat moved to Cangzhou in the Song, and in the Yuan the court set up a Changlu salt transport commissioner there to oversee sea salt production; from that point the name stopped belonging to one settlement and became the standing word for the salt-producing coast. Under the Ming a transport commissioner at Changlu town had twenty-four salt fields under him; under the Qing the area was reorganised as the Changlu salt district.
From the journal
The Salt Pans of the Bohai Shore
Salt made the western Bohai coast worth governing. Changlu was the name of the whole salt shore, taken from the reeds at the water's edge; the working fields today are on the Tianjin side.
In the same city · Binzhou ↗The name means reeds by the water
When salt was the treasury
For a few centuries the salt of this coast was money. In the Republic it was the largest sea-salt region in China; in the early 1930s its average output was about 15 per cent of the national total and its salt tax about 11 per cent, both first in the country. In the late nineteenth century Tianjin, living on Changlu salt as its main source of revenue, was once the economic centre of northern China, and a young French officer, arriving for the first time, is said to have exclaimed that it looked like a country made of salt. Industry followed the money: in 1914 the entrepreneur Fan Xudong founded a refinery at Tanggu that sold refined salt under the Sea King brand, and in 1918 the Hanguo field was enlarged with its own rail line.
Where Binzhou's salt ground begins
Today the fields carrying the Changlu name are on the Tianjin coast, with the modern industry grouped around Hangu, Dagu, Tangshan's Nanbu and Cangzhou's Huanghua, and Hangu also gives its name to the sea-salt geographical indication. East of Huanghua the shore is Binzhou's: 126.44 kilometres of coastline, 96,000 hectares of ground fit for salt, rock salt and natural brine among thirty-two proved minerals, and a prefecture that is Shandong's second largest sea-salt production base and home to one of the country's four fishing grounds. The saltworks leave archaeology behind too, in the Yangjia salt industry site group, one of the five national monuments. Flat ground, wide tidal flats, a short rainy season and hard sun are the conditions the whole shore shares.