Group 1 - The Jiangnan section of the Grand Canal in Zhenjiang is characterized by its high terrain and shallow water, historically making navigation difficult, leading to its nickname "the roof of Jiangnan" [1] - The section has undergone significant improvements since the establishment of New China, with five major renovations, including a notable one in 1958 that involved cutting nine sharp bends and excavating approximately 10 kilometers of the canal [1] - Historical artworks, such as the "Kangxi Southern Tour Map," depict the challenges faced by boats in this section, highlighting the role of "tugmen" who assisted in navigation through difficult waters [1][2] Group 2 - The Zhenjiang section of the Grand Canal faced severe water shortages in ancient times, often leading to navigation disruptions due to sedimentation and erosion [2] - Recent comprehensive renovations have transformed the Grand Canal in Zhenjiang, with modern infrastructure such as large bridges and high-speed railways replacing the traditional small wooden boats [2] - The once challenging "Taishan Bay" has now evolved into a vital waterway, referred to as a "water expressway," showcasing significant improvements in navigation and accessibility [2]