Human activity and damaging landslides and floods on Madeira Island

Abstract

Abstract.Over the last few decades, the island of Madeira has become an important offshore tourism and business center, with rapid economic and demographic development that has 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 landslide and flood events. As a result, the costs of restoration work due to damage caused by landslide and flood events have become a larger and larger component of Madeira's annual budget. Landslides and floods in Madeira deserve particular attention because they represent the most serious hazard to human life, to property, and to the natural environment and its important heritage value.The work reported on in this paper involved the analysis of historical data regarding damaging landslide and flood events on Madeira (in particular from 1941 to 1991) together with data on geological characteristics, topographic features, and climate, and from field observations. This analysis showed that the main factor triggering the occurrence of damaging landslide and flood events is rainfall, but that the increase in the number of damaging events recorded on Madeira Island, especially in recent times, seems to be related mostly to human activity, specifically to economic development and population growth, rather than to natural factors.

Geohydrological hazards and urban development in the Mediterranean area: an example from Genoa (Liguria, Italy)

“…variations in the flood channel width of the streams with a narrowing of the effective discharge section (Corominas and Alonso, 1990;Baioni, 2011;Faccini et al, 2014);…”

A dependence modelling study of extreme rainfall in Madeira Island

“…Other southern areas like Machico, Santa Cruz, Campanario, Ribeira Brava and Calheta were also affected by this devastating event. In the last century, six catastrophic rainfallinduced events were registered in Madeira, namely in 1920Madeira, namely in , 1929Madeira, namely in , 1956Madeira, namely in , 1979Madeira, namely in , 1993Madeira, namely in and 1997, totaling more than 60 deaths and several dozens of injured people and houses destroyed (see, e.g., Baioni, 2011;Fragoso et al, 2012;Quintal, 1999). More recently, already in the 21st century, two significant events of this type were registered in Madeira Island, the first in March 2001, with five deaths and material damages of several tens of million euros (Rodrigues and Ayala-Caicedo, 2003), and the second one in February 2010, which caused 45 casualties, six missed people, more than a hundred injured and about 1.4 billion euros of material losses (Baioni, 2011;Fragoso et al, 2012), which indicate an increase in the frequency of such events and in the damage caused by them.…”

“…In the last century, six catastrophic rainfallinduced events were registered in Madeira, namely in 1920Madeira, namely in , 1929Madeira, namely in , 1956Madeira, namely in , 1979Madeira, namely in , 1993Madeira, namely in and 1997, totaling more than 60 deaths and several dozens of injured people and houses destroyed (see, e.g., Baioni, 2011;Fragoso et al, 2012;Quintal, 1999). More recently, already in the 21st century, two significant events of this type were registered in Madeira Island, the first in March 2001, with five deaths and material damages of several tens of million euros (Rodrigues and Ayala-Caicedo, 2003), and the second one in February 2010, which caused 45 casualties, six missed people, more than a hundred injured and about 1.4 billion euros of material losses (Baioni, 2011;Fragoso et al, 2012), which indicate an increase in the frequency of such events and in the damage caused by them. This emphasize the need for appropriate statistical models of extreme hydrological events, particularly in the current context of global and regional climate and environmental changes, since the modelling of extreme rainfall has an important role in the design of water-related structures, in rural and agricultural engineering, and in many other areas, such as civil defense, where the hydrological monitoring and the knowledge concerning weather and climate extremes are fundamental.…”

“…Rainfall-induced debris flows are one of the most dangerous natural hazards in mountain regions (Hu et al, 2009), because their occurrence is unpredictable and this type of waterrelated natural disaster can be catastrophic, affecting significantly not only the landscape, but also causing damage to houses and infrastructures (Kanji et al, 2008), loss of lives (Wilford et al, 2004), and other negative economic and social impacts due to the increasing anthropisation of such areas (Hürlimann et al, 2006). Floods and associated landslides and debris-flows triggered by extreme rainfall events have been in reality the most devastating of natural disasters, both in Madeira Island (Baioni, 2011;Quintal, 1999) as in the rest of the world (Hong et al, 2007).…”

Semiautomated object-based classification of rain-induced landslides with VHR multispectral images on Madeira Island

“…1), with a population of 250 000 inhabitants, has a long record of flash floods, with at least 30 flash flood events of significant intensity registered since the beginning of the 19th century (Baioni, 2011;Lira et al, 2013). These flash floods usually last a few hours, during which a large amount of sediment is transported downstream very rapidly and with very high energy.…”