Water management in the karst of Apulia, southern Italy.

Among the peculiarities of karst environment, distinguishing it from any other natural settings, the very limited surface runoff and the slightly defined surface watersheds play a significant role. Notwithstanding such features, even in flat karst areas as is the case for most of Apulia (south-east Italy), the surface hydrographic lines were a very important element in the karst landscape, that greatly controlled location and spreading of the first human settlements in the region. In the centuries, the many interventions carried out by man have caused heavy changes in the original hydrographic network: swallets have been covered and/or clogged, water lines diverted, and a complex network of artificial channels progressively took the place of the original surface runoff. The artificial channels are still today used to discharge the urban and industrial wastewaters in many areas of the region. All this situation on the occasion of extreme rainfall determines floods, extending over wide areas, and, as indirect consequence, spreading of pollutants in the fields. Water management in the karst environment of Apulia is discussed in this paper. Two examples are used to describe both history of the anthropogenic actions, and the main effects they caused: Castellana-Grotte, in the Murge plateau, and Nardò, in the Salento Peninsula.