Historical flash flood impact in Mallorca and its futureevolution. Miquel Grimalt Gelabert, Joan Rosselló Geli.

Grup de Climatologia, Hidrologia,Riscs naturals i Territori . Universitat de les Illes Balears. E-mail: joan.rossellogeli@uib.es

Project RECABA. CGL2008-06129-C02-02/CLI

Historical and current spatial flash floods distribution .

The evolution of floods patterns in Mallorca has changedhistorically, due to social and territorial changes. Factorssuch as newest urbanizated areas and the use of the coast fortouristic activities are key for these changes.Factors as intensity, frequency and spatial location forhistorical and current floods have been analyzed. Floodtypologies have been established and evolution factors havebeen studied. Impact of man activities is the key to theevolution of the location of the main flood locations since the1960’s.

Identification of flood events fromdocumentary sources (1229-1900)

Clustering of events intocategories

Cartographicallocation of historical

flood events

Comparisonof historicaland currentdistribution

of flood-prone areas

Future perspectives References

The flood hazard has increased due to negligent buildingprocedures, induced mainly by the tourism industry. Theincrease of population caused by the tourism has led tooccupy flood-prone areas for building residential and leisurespaces.

Urban growth has occupied floodplains regardless of formeroverflow events and the construction of infrastructure suchas roads also effects helping the flood of urban spaces(Grimalt, 2001). The continued development pressure willlikely lead to increased risk cases in the near future.

Furhermore, the climatic change opens an uncertain futureof flash-flood impact as an increase of precipitation of highintensity is expected, precipitation having a great influencein the generation of floods.

In conclusion, recent flash-flood events and the futureprospects lead to the perception that there will be anincrease of the flooding cases in urban areas of Mallorca. Plans to act have been created by authorities but there are failures, specially as the population does not assume or know the existing risk (Rosselló, 2009).

Grimalt, M. (1992): La geografia del risc a Mallorca: les inundacions. EstudisBalearics. Palma.

Grimalt, M. (2001): Les catàstrofesclimàtiques a les Illes Balears. Les inundacions. In: Pons, X. i Guijarro, J. (eds): El canvi climàtic: passat, present i futur. Mon. Soc. Hist. Nat. Balears, 9: 191-203.

Rosselló, J.; Rosselló, Q. (2009): Riscsnaturals , aproximació als fenòmensextrems a Sóller i Fornalutx. III Jornadesd’Estudis Locals. Ajuntament de Sóller. 169-186.

Methodology

The poster analyzes the flood impact in Mallorca from an historical perspective with a focus onthe latest events and its future evolution. A change in the location of the main flood events sincethe 20th century as well as a change on the impacts related to floods has been found.The impact has changed from low cost effects on agricultural areas to expensive damagesaffecting public and private buildings as well as roads, bridges and touristic resources, speciallyin the coast. The future evolution shows a possible increase of the flood events and its impact as the use offlood-prone areas has increased due to the population growth and the expansion of urbanizedland.

Flash floods with a great destructive power and high instant flowpeaks are characteristics in Mallorca’s history. Image: flood in thetorrent de sa Riera (Palma) in 1942 (Source: arxiu VILA).

Identification of flood events fromsources as press, oral sources, graphicand official documentation (1900-2005)

Clustering of events intocategories

Cartographicallocation of actual flood

events

Characterization oftypologies of

historical floods

Characterization oftypologies of

current floods

Analysis ofthe causes of

change in the

territorial distribution

of floods

Possiblefuture

evolution

Historical floods locations

cities

intensiveagriculturalareas

Sóller

ManacorPalma

Sa Pobla

Campos

Current floods locations

coastal turistic areas

new developedurban areas

Historical flood events Current flood events