GE CLST M1A Lecture Notes - Lecture 20: Maritime Geography, Vadose Zone, Food Security
Document Summary
Health: mental, social, physical, well-being; not just un-diseased. Freshwater: relatively pure with few dissolved salts, only 2. 5% of total water. 79% freshwater is tied up in glaciers & polar ice caps, and is inaccessible. The hydrologic cycle: evapotranspiration: evaporation and transpiration. Transpiration: plants take in water through roots and release it through leaves. Evaporation: radiant energy from sun heats water, causing water molecules to be so active that some rise into the atmosphere as vapor: condensation: water changes from vapor to liquid. Cloud formation: precipitation: water releases from clouds as rain, sleet, snow, hail, surface runoff: precipitation turn to streams, lakes, etc, infiltration: a portion of the precipitation water seeps underground. Hits water table, where the spaces between rocks and particles are saturated. Instead of treating water from treated waste water, we are more comfortable with infiltrated water from sewers that is in fact contaminated with chemicals. Freshwater shortages are affecting millions in the world.