13世纪中叶,北方历唐末、五代、宋、辽、夏、金、蒙古长达数百年战乱,社会经济遭受严重破坏,刚刚建立起的元朝为稳固政局,元世祖忽必烈大量征收南方粮食,即南粮北运。当时江浙行省征收的粮食将近全国各行省总额的二分之一。原先江浙一带的漕粮从扬州沿古运河北上,途中装卸三次,十分不便,因此单靠运河的运输能力不能及时解决问题。如何把江南粮食调运到京都,成 In the middle of the 13th century, the Northern Dynasties experienced many hundreds of years of war and social and economic suffering in the late Tang Dynasty, the Five Dynasties, the Song, Liao, Xia, Jin and Mongolia. The Yuan Dynasty just established a stable political situation. Kublai Khanate Grain, that is, South grain North Games. At that time, the grain levied by Jiangsu and Zhejiang provinces and provinces was nearly one half of the total amount of all the provinces in China. The original Jiangsu and Zhejiang area along the grain transport grain from Yangzhou along the ancient canal north, loading and unloading three times on the way, very inconvenient, therefore, can not rely on the transport capacity of the canal in time to solve the problem. How to transfer the southern grain to Kyoto, into