The landscape of man-made terraced slopes in Cinque Terre (Liguria, Italy): a world heritage site at geomorphological risk

Since about 1100 A.D. most of slopes of Liguria have been terraced for agricultural purposes through reworking of millions cubic meters of debris and the construction of thousands kilometers of dry-stone retaining walls. In particular the man-made terraces at Cinque Terre (eastern Liguria), due to their great extent, peculiar construction characteristics, high historical and cultural value, are one of the most famous and emblematic examples of landscape evolution in the Mediterranean area. Therefore the Cinque Terre were included in the \u201cCinque Terre National Park\u201d and recognized as a world heritage by UNESCO since 1997.On an area of ca. 20 km2 a total lenght of nearly 6000 km of terraces, which were cultivated for vineyards and olive groves, can be estimated. Man-made terraces have represented over the centuries a basic factor for erosion control and landslides prevention at Cinque Terre, where geological and geomorphologic complex settings favor slope instabilities. Instability phenomena are increasing during the last decades consequently to the progressive abandonment and degradation of cultivated terraces, which played an important role on water control over the past centuries. Currently, entire sectors of terraced slopes - up to several hectares - have been lost. In this framework, also taking in account the climate change, detailed studies of the relationships between geological-geomorphological conditions and the state of conservation of the terraces are fundamental both for the evaluation of slopes stability and risk scenarios. Currently, a scenario of high geomorphological risk is rising at Cinque Terre. That can also be seen at regional, national and Mediterranean scale in other abandoned terraced areas, which primarily require conservation strategies for preserving the memory of the rural culture and its interrelations with geo-hydrological and landscape dynamics, and for promoting sustainable development of agriculture and tourism