Historical, biological and morphological aspects of the Roccarainola qanat in the district of Naples, Italy

Abstract

A qanat is an underground channel consisting of verticals shafts connected at their bottom with a sub-horizontal tunnel bringing water from an aquiferous stratum, with a slight downward slope useful for the water tapped to run down it and into the open air by gravity. Qanats were first developed in Kurdistan as a side result of mining activity by the early millennium B.C. at the latest. Qanats exist in more than 34 countries all over the world, but most are concentrated in present day Iran. In Italy, Sicily is usually cited for its “Ingruttati”, but also in the Campania Region, there are some qanats (“Qanate”). As a matter of fact, this paper describes the historical, biological and morphological aspects of the Roccarainola qanat located in the district of Naples, in Southern Italy. It dates back to the Roman Ages, but currently the hypogean environmental condition misrepresents its ancient state. The animal species discovered forty years ago in the Roccarainola qanat were substantially small sized arthropods, a planaria and some species of bats. The Roccarainola qanat is composed of three branches for a total length of 786 m, with a drop of 9 m. The tunnel slope varies from around 1.70 cm/m to 5.20 cm/m. However, original slopes have been modified due to accumulation of debris and waste. Seventeen vertical shafts (not internally covered) with a circular section were found along the hypogeum. On the average, the shafts are spaced 36.5 m apart.