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]

Core Viewpoint - The article highlights the historical and cultural significance of the Daicun Dam, which has been a crucial infrastructure for water management and navigation in the Grand Canal system for over 600 years, and its recent recognition as a heritage site by the Ministry of Water Resources in China [4][5][9]. Group 1: Historical Significance - The Daicun Dam, located on the Dawan River in Shandong Province, has played a vital role in directing water flow to the Grand Canal, facilitating transportation and flood control throughout its history [4][6]. - The dam was constructed to address the challenges posed by the high terrain of the Grand Canal in the Jining Nanwang section, which hindered the passage of large vessels [5][6]. Group 2: Engineering and Design - The dam's design includes a main stone dam, a Dougong embankment, and a spillway, which work together to manage water flow effectively [7][8]. - The foundation of the dam is reinforced with closely packed cypress piles, which are treated to enhance durability and reduce water absorption, ensuring stability against flooding [7][8]. Group 3: Modern Developments - Since 2022, the Daicun Dam has transitioned from its original function of water diversion to becoming a recreational area, attracting visitors for leisure activities and cultural tourism [9][10]. - The local government is promoting the integration of water management with cultural tourism, enhancing the ecological environment and preserving the heritage of the Grand Canal [9][11].