Assessment of microscale economic flood losses in urban and agricultural areas: case study of the Santa Bárbara River, Ecuador

To reduce and prevent significant economic flood losses, reliable tools are required to estimate potential river inundation effects. This paper focuses on the estimation of direct damages caused by flooding with different return periods in urban and agricultural areas. A univariable deterministic flood loss model was developed to estimate potential damages, based on water depth. This approach involved assessing the mapping of local flood risks based on the combination of historical inundation marks, land-use and economic data. The primary objective of this study is to determine whether it is possible to use accessible data at the municipality level to assess economic flood losses. For the Santa Bárbara River case study, the results reveal that the greatest proportion of damages (approximately 99%) is expected to occur in the urban area. In addition, results showed that the approach is useful for identifying and mapping flooded areas with critical damage. The proposed methodology can be applied to microscale analysis, thereby providing quantitative results for flood risk assessment, the outcomes of which could assist local decision-makers in the prioritization of critical risk areas, and the development of mitigation options and countermeasures. As such, this is the first study to propose and provide an open-access methodology for quantifying flood losses in the inter-Andean region of Ecuador.