EESA01H3 Lecture : Chapter 11 Notes.docx
Document Summary
Roughly 97. 5% of earth"s water resides on the oceans and is too salty to drink or to use to water crops: 2. 5% is considered freshwater , water that is relatively pure, with few dissolved salts. Some of which is tied up in glaciers, icecaps and underground aquifers, just over. 1 part in 10000 of earth"s water is easily accessible for human use. Water is moving among reservoirs via the hydrological cycle: as it moves it redistributes heat, erodes mountain ranges, builds river deltas, maintains organisms and ecosystems, shapes civilizations, and gives rise to political conflict. Water from rain, snowmelt, or springs runs downhill and converges where the land dips lowest, forming streams, creeks or brooks: these watercourses merge into rivers, which eventually lead to ocean. A small river flowing into a larger one is a tributary. The area of land drained by a river and all its tributaries is that river"s drainage basin or watershed.
