Fig. 1: Spatial distribution of long-span pipeline risk assessment in Hong Kong.

The figure presents a multi-panel map showing the risk assessment of long-span pipeline networks in Hong Kong. The central panel (red border) displays the main overview of Hong Kong Island, Kowloon, and surrounding areas, with pipeline segments color-coded according to risk levels: high-risk (red), medium-risk (orange), low-risk (yellow), and safe-level (green). Two detailed inset maps are shown in black and blue borders, focusing on specific districts with dense pipeline networks. The top-right corner includes a smaller overview map (green border) showing the geographical context of the study area, and a legend indicating the risk level classification. A north arrow is provided for orientation. The purple boxes in the main map highlight urban areas with detailed views.