Hydraulic Engineering and Historical Aspects of the Pre-Columbian Intravalley Canal Systems of the Moche Valley, Peru

AbstractAbstractThe major intravalley canals of the Moche Valley in Peru built during the Late Intermediate Period (ca. 900–1400 A.C.) are analyzed for their engineering design content and design philosophy. An historical overview of the canals reveals successive abandonment of older, higher outlying canals in favor of near-river systems of lesser length. With this retraction there is a concomitant decrease in irrigated land. This paper ascribes this process to tectonically induced coastal uplift and its subsidiary effects. Seen in this perspective the Moche Valley canal sequence represents a logical defensive engineering strategy for combating the destructive effects of tectonically induced landscape changes upon fragile slope-sensitive canal systems. This paper, thus, deals with the process of agrarian collapse and its origins within the Moche Valley. This process, begun in antiquity, continues to the present day, as evidenced by the fact that only 35–40% of ancient arable lands are now under cultivation.