Аннотация:Abstract Abstract Val-di-Chiana, a fertile alluvial valley in north-central Tuscany, was extensively settled by the Etruscans and Romans, but stream gradients were insufficient to prevent the floodplain from turning into a silty wetland after deforestation and tectonic uplift had accelerated the rate of sedimentation by tributary streams. Malarial infestation began in Etruscan times with the inception of marshes and became serious during the Middle Ages and Renaissance, when the wetlands extended over 140 sq. km. Drainage modification was first suggested during the 1300s, and by 1500 had become an important land reclamation strategy in the valley. An artificial channel, the Canal Maestro, was eventually dug in order to reverse the direction of drainage from southward into the River Tiber to northward into the Arno. At the same time tributary streams were canalized, and artificial drainage divides and walled sediment traps, known as colmate, were constructed. Many eminent men were involved in the debate over the best strategy for land reclamation in Val-di-Chiana. Among them was Count Vittorio Fossombroni, who superintended completion of the Canal Maestro in 1840 and wrote an important monograph on the history of Val-di-Chiana, which also contributed to the development of theoretical geomorphology and hydrometric instrumentation. Key Words: land reclamationriver managementItalyhistorical geographyhistory of geomorphology
