Influence of Anthropogenic Activity on the Development and Spreading of Flood Hazardous Events in Madeira Island (Portugal)

Abstract

Over the last few decades, the island of Madeira has become an important offshore tourism and business centre, with a rapid economic and demographic development that have caused changes to the landscape due to human activity. In Madeira’s recent history, there has been an increase over time in the frequency of occurrence of damaging flood events. As a result, the costs of restoration work due to damage caused by flood events have become a larger and larger component of Madeira’s annual budget. Flood phenomena on Madeira deserve particular attention because they represent the most serious hazard to human life, property, and the natural environment and its important heritage value. The work reported in this paper involved the analysis of historical data regarding damaging flood events on Madeira in particular for the period from 1941 to 1991, together with data on geological characteristics, topographic features, and climate, and from field observations. This analysis showed that the increase in the number of damaging flood events recorded on Madeira Island, especially in recent times, seems to be mostly related to human activity, specifically to economic development and population growth, rather than to natural factors.