Structural measures against floods on the Spanish Mediterranean coast. Evidence for the persistence of the “escalator effect”

Abstract

The risk of flooding on the Spanish Mediterranean coast is a constant threat whose importance has progressively increased in recent decades despite the enormous efforts made to mitigate it. Of the two strategies practiced to reduce the effects of this danger, structural measures have prevailed to a great degree over non-structural ones during this period of increased risk. Here, these works carried out from the beginning of the 20th century to the present are cataloged, with a double objective: (i) to show the evolution of the number of infrastructures, their typology, and their distribution on the Mediterranean coastline; and (ii) to evaluate whether the basins with and without a dam have followed differing trends in the occupation of floodplains to show the persistence of the “escalator effect”. The results obtained indicate that there is no statistically significant difference between the occupation of the floodplainsby basins with and without a dam for the Return Periods (RP) 50, 100, and 500 years. However, for RP10, there is a higher occupation by basins with a dam.