Hydrogeological Damage: An Overview on Appraisal Issues

The growing frequency of hydrogeological instability reflects the fragility of many territories, due to their geological, geomorphological, and hydrographic conformation. In addition, human actions, such as continuous deforestation, intensive urbanisation, unauthorised building, and lack of maintenance of slopes and watercourses, contribute to and encourage these events. The resulting damage involves the population, infrastructure, real estate, and the environment. This has serious economic, social, and environmental repercussions. The analysis of a phenomenon of hydrogeological instability certainly can’t elude an economic-estimative investigation. This study intends to address the issue of estimating the costs necessary to restore the status quo ante, with specific reference to a hydrogeological instability that involves an urban area. To this end, first, the cost approach is introduced. Then, the analytical estimation procedure and the synthetic-comparative estimation procedure are exposed, both useful to evaluate the reconstruction cost, highlighting their limits and advantages. Finally, a database of parametric reconstruction costs in the Campania Region (Italy) for different types of civil works is built. This represents a tool available to operators for applications aimed at expeditious estimation of damage from hydrogeological instability.