A river that rises in a humid region and flows through an arid region, with discharge decreasing toward the mouth; for example, the Nile River and the Colorado River.
o • rivers have played important role in agriculture, transportation, industrial uses, removal of excess waste, etc. human pop'n grew alongside
o • e.g. North Carolina (1999): Hurricanes Denis, Floyd and Irene (Sept-Oct) deluged NC with several feet of pptsaturated ground; flushed out waste lagoons (each hog 2 tons/year of waste) set on floodplains sent into the ocean dead zone
o • e.g. Bangladesh: 3⁄4 of area on floodplain, densely populatedupstream forest harvesting of Ganges-Brahmaputra watershed leads to increased run-off higher sediment loadsdeposited in delta regions forming island used as nascent farming communities (150,000 dead during flooding 1988, 91)
o • rating floodplain risk: flood - high water flow, over-topping levees; statistically rated for time interval between floods of a certain magnitude - e.g. 10 yr flood (the greatest level of flooding likely to occur every 10 years; 10% chance every year)
exotic stream: Q decreases with distance (high POTET rates arid environments) - e.g. Nile River, Colorado