How did the grand canal affect trade in china?

The Grand Canal connected two of China's most important water basins, and a large amount of wealth was dervived from canal trade. Which basically means that the Grand Canal was a convient way to trade and that many people used it. 

Master planned communities outside of chicago. note: population density means people living in an area per square mile. chicago, an urban and highly populated area has a much more higher density than a desert, amish community, settlement, or nomadic region.