410 likes | 604 Views
WATER. WE LIVE ON A WATER PLANET. WE REQUIRE WATER (FRESH) TO SURVIVE. BUT, MOST WATER IS SALTY AND FRESH IS LIMITED. MAYBE THERE IS A WAY – KNOW YOUR PLANET. MOST ALL LIVING THINGS REQUIRE WATER. From the sea we and all evolved. Our blood chemistry and tissue fluids
E N D
From the sea we and all evolved • Our blood chemistry and tissue fluids mark all of us – it’s salty; and
ONE-salt water • Greatest mass – 97% • 3.5 wt% dissolved material • Covers 71% of Earth
TWO-fresh water • 4 places • Atmosphere as gas • On land surface as liquid • In the land as groundwater • On land as ice • Low content of dissolved material • Most land life requires fresh • Limited – only as rain
ONE-solid • Density = 0.92 g/cm2 • Types • snow • glaciers • polar caps, when present
TWO-liquid • Density = 1 g/cm2 • Types • rain • as small, suspended droplets • seas • on and in land
THREE-gaseous • Density varies but (typically) <1 g/cm • Not visible
Effects of pressure and temperature • The changes of state • (in pure, standard system) at 0o and 100o C
Structure and properties This end a partial - charge This end a partial + charge
Structure and properties-cont. • Excellent solvent
Structure and properties-cont. • When hot and under high-pressure –nearly a universal solvent
Structure and properties-cont. • Disassociation HOH OH- + H+
Structure and properties-cont. • Liquid solid (EXPANDS!)
Structure and properties-cont. • In atmosphere exists as both liquid and gaseous – because the atmosphere is a mixture of gasses
THE WATER CYCLE An internal system driven by an external source of energy
gaseous • Mostly as one of atmospheric gases
liquid (not including atmospheric) • EROSION • by wave action • by flowing water water doesn’t run!!! • STEAM CYCLES DRIVEN BY GRADIENT • flowing water creates valleys • GROUNDWATER • In upper porous and permeable soil and alluvium
solid • Polar caps and large ice masses • Thick enough to cover the land completely • Or to form significant floating masses • Ice confined to valleys • Thin enough to be confined by topography • Shapes the valley differently
‘NEW’ SOURCES OF FRESH WATER Things to do
California’s rain • Storms mostly from gulf of Alaska
Water Law – a mess • Riparian rights (state) • Appropriative rights (state) • Reclamation laws (federal) • Environmental laws (state and federal)