How did the construction of the Grand Canal under the Yuan dynasty affect older waterways in Anhui?

The construction of the Grand Canal during the Yuan dynasty (1206–1368) led to the decline of older waterways in Anhui.1

Prior to the Yuan period, the Bian Canal—specifically the New Bian Canal constructed during the Sui dynasty—served as a vital communication and transport line, running through Anhui to carry tribute grain to the capital. However, when the Yuan dynasty established its capital at Dadu (modern Beijing), it prioritized the construction of a new north-south Grand Canal located further to the east. As a result of this shift in the empire's political and logistical focus, the previously established east-west canal networks that traversed Anhui lost their strategic importance and fell into disuse.12