Extraction of Deterioration and Analysis of Vegetation Impact Effects on the South Palace Wall of Weiyang Palace

Abstract

Weiyang Palace, as the royal palace of the Western Han Dynasty, is a part of the Silk Roads: the Routes Network of Chang'an-Tianshan Corridor on the World Heritage list. The south palace wall of Weiyang Palace is a well-preserved earthen site within the palace, but it is undergoing continuous deterioration due to the influence of vegetation and external environmental factors. This study pioneers the integration of high-resolution three-dimensional LiDAR scanning with multi-source data analysis, including unprecedented on-site botanical surveys, to elucidate the nuanced impacts of different vegetation types on the structural integrity of the south palace wall. Through contour line analysis and facade grid analysis, we extracted the deterioration locations of typical sections of the earthen sites. And we classified the overlying vegetation types on the wall using an object-oriented classification algorithm. Our findings reveal a complex interaction between vegetation and earthen structures: paper mulberry exhibits protective qualities against erosion, while ziziphus jujuba significantly exacerbates structural vulnerabilities by inducing cracks. Methods employed in this study for extracting earthen site deterioration and combining multi-source spatial data analysis can serve as a technical application model for monitoring and analyzing the driving forces of surface earthen sites along the entire Silk Road network, thereby better guiding the conservation of earthen sites.