Earth Sciences 1022A/B Lecture 16: Earth Science Lecture March 10 2016
7 Aug 2016
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Document Summary
Takes a long time to get water underground and is most effective by steady rainfall soaking into the ground because of heavy rain produces mostly runoff and little infiltration once plant requirements are met. Zone of saturation: pores of sediment or rock are completely filled with water. Zone of aeration: pore contain mainly air and a minor amount of water held as soil moisture. The surface between the two zones is called the water table that mimics the land surface. The water table is highest under hills and lowest under valleys. Very slow as it depends on the nature of the materials: cm/day. Porosity: volume of open space in rocks or sediment. Porosity is reduced by pores getting filled in with cement and fine particles. Permeability: connection of pore spaces and ability of material to transmit water. Permeable material is called aquifer: groundwater flows under gravity in a pattern of long curving paths toward streams.
