Fig. 1: Study area.

a The main map illustrates the Ningbo Section of the Grand Canal of China. Elevation is shown with a gradient from light green (low, 0 m) to dark green (high, 958 m), and the county boundary is outlined in gray lines. Red triangles denote agrarian cultural heritage (ACH), orange pentagons denote maritime fishing cultural heritage (MFCH), and blue circles denote maritime trade cultural heritage (MTCH). The Grand Canal of China is indicated with blue lines, with the Ningbo Section specifically highlighted in light blue. b The inset map shows the location of Zhejiang province within China. Open rectangles indicate the boundaries of other provinces, the Grand Canal of China is marked in blue, and Beijing is identified with a red star. The small inset in the lower right displays the outline of islands in the South China Sea. c The inset map highlights Zhejiang province, with the study area shown in red and surrounding cities within Zhejiang displayed in light green (drawn by authors).