DECISION TREE ANALYSIS OF PROCESSES GENERATING WATER-RELATED BUILDING DAMAGE: A CASE STUDY IN ROTTERDAM, THE NETHERLANDS

摘要

The objective of this study was to identify the main failure mechanisms behind water-related building damage and to investigate to what extent these processes are related to characteristics of buildings and rainfall events. Results are based on the mining of property level insurance damage data, for a case study in Rotterdam, the Netherlands. This study has found that most frequent causes of water-related damage relate to roof leakages (28%), bursts of household water supply pipes (19%) and blocked household wastewater systems (18%). Cases of sewer flooding or depression filling were less present (2.4% and 0.6%), but showed stronger correlations with heavy rainfall events than any other failure mechanism. Classification tree analysis revealed that water discharges from neighbours is the main damage cause for high-rise buildings on days with no or minor rainfall (＜ 7.5 mm/h). Moreover, damage due to blocked household wastewater systems is associated with low-rise buildings younger than 50 years.