运河,作为古今中外存在广泛的人工河道景观,有着丰富的历史地理内涵。《新大英百科全书》里说,"Canal,artificial waterway built for navigation,crop irrigation,water supply,and drainage. Canals are usually connected with natural bodies of water or other canals"(1)。即其认为,"运河是为航行、作物灌溉、供水和排水而建造的人工水道,它们通常与天然水体或其他河道相连接"。