Ancient water systems and hydraulic devices

摘要

The earliest designs and applications of water systems initially started with irrigation. Those areas that had level land, warm climates, and of course proximity to streams, were among the first to develop techniques that supplied sufficient amounts of water. Accordingly, the early soci eties that occupied Egypt, Mesopotamia (central Iraq), the Lower Indus River (Pakistan and a portion of north western India), and the Yellow River valley in China were among the first to establish productive agricultural sys tems. Other societies at different times were also con cerned with storing water for immediate and/or later use by building cisterns, dams, and reservoirs, while others developed techniques for flushing wastes away from populated areas. Some civilizations are well known, oth ers less so. As expected with dating events that go back nearly 7,700 years ago, different scholars have suggest ed a variety of time periods for different phases of water development. Table 1 provides an estimate of time peri ods that show the variation in water development tech niques for a selective sample of locations.