GEOG 1700 Lecture 12: Chapter 5
Document Summary
Physical boundaries helped create cultural region distinguished by. Temperature and rainfall= 2 of most important factors for a biome, or large ecological unit with similar vegetation and climate. High pressure cells lead to dry air around tropic of cancer (24. 5 degrees north), which runs through region. Often perceived as scare and root of ethnic tension. 2 major river systems: nile and tigris and euphrates. Once much wetter region: been arid for 9,000 years. Qanats, or underground conduits, collect water from aquifer on slope of hill. Use natural gradient of land and gravity to transport water underground to agricultural areas or towns. 1st developed in iran: predated roman aqueducts. Despite age, much of ancient qanat network still works. Qanat technology made it possible to develop and sustain crop agriculture in water scarce region. Unlike modern irrigation, does not deplete aquifer or require energy to move water, and the quality of the water is maintained.
