Rainfall-related impacts on a terraced landscape: Sóller valley (Mallorca, Spain) December 2016-January 2017

Abstract

High Precipitation Events (HPEs) are common in the Mediterranean basin, causing effects such as floods or landslides. Those effects cause impacts, ranging from economic damages to the loss of life. Amongst the damages, the impact on man-made landscapes is also common, affecting both rural and urbanized spaces. The terraced land, built across the Mediterranean, for farming purposes, suffers from HPEs when the terraces cannot cope with the large amount of falling rain. In that sense, it is important to study how rainfall affects the terraces in terms of rock fall and mass movements. Such impacts can damage the economic purpose of the farmlands but also affect other activities developed on rural spaces, like trekking or biking. In this research, the impact of precipitation over a heavily terraced valley in Mallorca is studied, both in terms of impacts and regarding human-related leisure activities as well. The methodology follows five steps, combining aerial photos and satellite images analysis with fieldwork and the study of the obtained data using computer tools. The results show how the terraces cannot cope with large amounts of rain, which increase the risk of collapse and affecting activities developed in these areas. The need of measures to protect those cultural landscapes is highlighted as well as the need of an improved statistical analysis, because results show a moderate correlation between rainfall and stones movement across terraces.