A cloud model-based quantitative assessment system for surface deterioration of Taihu rockery in Jiangnan gardens: Yunwu rockery in Humble Administrator’s Garden

The Jiangnan Garden Rockery heritage site holds the largest number and highest aesthetic value of rockery among China’s classical gardens. However, its surface has significantly deteriorated. To support conservation planning, this study developed a quantitative evaluation system using a cloud model to enhance reliability and accuracy.. The system classifies deterioration into five levels and was validated through on-site surveys. Digital modelling of artificial rockery provided the ratio of deteriorated to total surface area, indicating Level 3 deterioration. Comparative experiments used ultrasonic velocity and Leeb hardness as degradation indicators. Based on existing standards and prior research, classification criteria for stone cultural relic deterioration were established. Measurements taken from degraded surfaces matched Grade III deterioration. Consistent results over three sets of experiments verified the evaluation system’s scientific validity.