永定河
In 1344, however, a grand plan to divert the Yongding River to facilitate water transport to the capital of Dadu (modern Beijing) generated heavy opposition, and Toqto’a resigned, joining his father in Gansu. During the 1330s, plague and famine devastated the Huai River area, while unrest appeared in the South Chinese, Manchurian, and the Tibetan borderlands. Massive flooding of the Yellow River inundated more than a decade of cities, putting the Grand Canal out of service and beginning the river’s migration to a new channel north of the Shandong peninsula. Meanwhile, piracy made the sea route for transporting South Chinese grain to the capital increasingly risky. Toqto'a's successor, the new councillor, Berke-Buqa, was too weak to handle all those issues. In August 1349, Toqto’a was recalled to the imperial capital and reappointed grand councillor.