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Water 1: Processes. Water: Celebrated Throughout History. Water, water, everywhere, And all the boards did shrink. Water, water everywhere, Nor any drop to drink. - Samuel Taylor Coleridge (1772-1834), "The Rime of the Ancient Mariner" 1798 .
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Water: Celebrated Throughout History Water, water, everywhere,And all the boards did shrink.Water, water everywhere,Nor any drop to drink.-Samuel Taylor Coleridge (1772-1834), "The Rime of the Ancient Mariner" 1798 "When the well is dry, you know the value of water.” -Benjamin Franklin "Whiskey is for drinking; water is for fighting over."- Attributed to Mark Twain
Water Cycle • Abundance is not a problem • Distribution and time of occurrence are the problems; needs to be in the right place at the right time • As water moves from one reservoir to another, it carries sediment, chemicals, waste, nutrients, etc. • 1 is balanced by 2 & 3 • 3 is balanced by 6 • 3 & 4 are balanced by 5 • 60% of terrestrial precip evaporates (4), whereas 40% returns to ocean (6)
World’s Water Supply Source: U.S.G.S.
Water: Unique Liquid (H-O-H) • General Properties • Covalently bonded – electron sharing • Dipolar – charge distribution leads to … • Cohesion vs. adhesion (hydration of clay particles) • Triple point on phase diagram (s-l-v) – transfers easily between water cycle reservoirs on Earth • Specific heat – great capacity to store and absorb heat • Only common substance with a solid form lighter than its liquid form – why ice floats
Surface Runoff and Sediment Yield • Effect of underlying geology (rock type) on surface run-off within a watershed or drainage basin • Large drainage basins are divided into smaller basins • Rain falling on either side of a divide may end up in very different places
Factors Affecting Runoff • Geologic factors (drainage density) • Physiographic factors • Basin shape • Relief and slope • Orientation of stream basin • Climatic factors • Timing and magnitude of precipitation • Biologic factors • Vegetation – interception/transpiration efficiency • Animals – burrowing/grazing • Soil organisms – opening of macropores to enhance infiltration capacity of landscape
Surface Runoff Runoff Paths • Throughflow – shallow subsurface flow above water table • Overland flow – when precip. Intensity exceeds infiltration capacity • Groundwater flow – movement through the saturated zone