干旱区生态环境知识资源中心

The Hohokam (AD 100-1450), their descendants the Akimel O’Odham (>AD 1694) and the white pioneers (19th c. AD) have cultivated and irrigated the lower Salt River valley in the semi-arid Phoenix Basin for almost two thousand years. This occupation is characterized by major changes in agriculture, social organization, architecture and landscape, which have modified this semi-arid valley on the long-term. Because of the continuous interaction of its members with water, a rare resource used in the region for domestic and agricultural purposes, the question of its availability and scarcity on the long-term needs to be answered. To do so, we have reconstructed the evolution of the Salt River alluvial dynamics by means of a systemic geomorphological and chronological approach. Second, in order to measure how these communities have adapted to hydro-climatic changes in a constraining environment, we have confronted these results to archeological, paleoenvironmental and ethnographic data on water management, agrarian practices, subsistence strategies and settlement pattern. The results obtained allow us to discuss the relative impact of human factors, such as human pressure and environmental constraints, mainly abrupt climate changes, on the cultural evolution of agrarian communities and therefore suggest an illustration of systemic answers to ecological and social issues in semi-arid environments.