Water Management in Ancient Peru

摘要: Water management in ancient Peru began the north coast Zana Valley (Fig. 1). Here a 2.5 km-long canal dating to 4705 BCE was sourced by Rio Nanchoc and supplied water small field system (Dillehay et al. 1997). Upon excavation, two additional, earlier profiles lay bedded below topmost profile. Apparently earliest, bottommost covered soil deposition episode requiring construction of higher level canal; this later event uppermost built. Starting from deepest canal, each successive had shallower slope built over depositional layer covering previous canal. The cross-sectional area increased highest In essence, ancients discovered basic tenet fluid mechanics: maintain same flow rate for all phases, must increase as decreases. From these early origins, archaeological record demonstrates continued progress hydraulic technology millennia meet demands large populations predictable food supplies. Ancient Peruvian civilizations exhibited wide variety agricultural systems compatible with different ecological conditions found coastal highland settings. societies farmed alluvial river valleys using rivers supply networks supplying systems. south areas where were deeply downcut tectonic uplift unable support irrigation, underground galleries cut deep into groundwater aquifer conducted distal surface contrast irrigation practices, Andean agriculture depended on mountainside terraces rainfall valley bottomland runoff streams originating mountainous watershed regions. A characteristic revealed their vulnerability periodic El Nino flooding drought (Moseley, 1987, 1997, 2008; Ortloff, 2009). Climate research (Abbott, 1997; Binford, Kolata, & Brenner, Shimada, Schaff, Thompson, Moseley-Thompson, 1991; Thompson al., 1982, Hastenrath, Arnao, 1989; Weng 2000) reveals sixthand tenth-century CE periods affecting survivability major (Ortloff Moseley, Fig. 2). other cases, caused severe damage canals through deposition/erosion events geophysical landscape change that degraded marine resource (Contreras, 2010; Moseley Deeds, 1982; 2012). For extensive periods, indicates migration homeland greater water/land resources (Dillehay, 2001). intervalley projects initiated transfer adjacent, water-rich resupply desiccated intravalley canal-supplied (Ortloff, Feldman, 1983). Where reconstruction/repair solutions not feasible whose did permit modification or innovative management/transfer solutions, disappear societies, terrace able elevations levels prevailed initiated. Bolivian