The flood of October 9, 2018 in the city centre of Sant Llorenç des Cardassar (Mallorca)

Abstract

Since the 1940s, the city centre of Sant Llorenç des Cardassar has suffered from several flooding episodes from the several tributaries of ca n’Amer creek. Five lives lost and a significant impact on the population were the result of the most relevant flood in the series that occurred in 2018. In this paper, an analysis of the historical relationship of the village with floods, the answer provided by the administration to those floods, and the geographic setting and the anthropic actions on the land are considered. Using the data collected by direct observation, witnesses, and graphs and fieldwork, a thorough investigation of the volume, flow, direction and levels of water has been developed. This translates into an exhaustive mapping of the event, discriminating the hydraulic behaviour in each of the affected roads and showing the sequential development of the flood. Flooding is a combination of severe stream flows, avulsion processes and angular sections that combine with infraestructures that interfere with the flow direction and prevent its reintegration into the main channel and where the streets become active channels.

Keywords

• natural hazards
• geography of risk
• mallorca
• sant llorenç
• flash flood
• urban floods