《天工开物·中篇·舟车》
从中夏到中秋期间，江水涨满封峡，船就停航几个月，等到以后水位降低，船只才继续开始往来。
中夏至中秋川水封峡，则断绝行舟数月。过此消退，方通往来。
<number>. During the period from mid-summer to mid-autumn, the river would fill and block the canyon, resulting in ships not being able to sail for a few months until the water level dropped so that ships could continue sailing.