The River Po, which Italians once feared for its flooding, is vanishing as a result of drought, industrialisation and other interventions. Over nine months, Tobias Jones travelled its 400-mile course from delta to source, by canoe, bike, foot and car. In a new book, The Po: An Elegy for Italy’s Longest River (Head of Zeus, £25), he sets out to show that we stand to lose not just a waterway but the many cultures that surround and are sustained by the river. He introduced the book with a piece published today in the New Review section of The Observer.