GL102 Lecture Notes - Lecture 9: Viscosity, Aquifer, Hydraulic Head
Document Summary
Streams lengthen their course by headward erosion: extending valley head upslope. Headward erosion may result in stream piracy: the diversion one stream into another. When the stream that cut the notch has its course changed by a pirate stream, a wind gap may occur (abandoned water gap) Groundwater: water in pores of soil and sediment, plus narrow fractures in bedrock. Largest reservoir of fresh water readily available to humans. Groundwater slowly dissolves rock such as limestone, creating surface depressions: sinkholes. Figure 16. 1 - groundwater, lakes and reservoirs, river water volume of fresh water (km3) (highlight these) Water held by molecular attraction on soil particles near the surface. Water percolates downward: zone where all open spaces are completely filled with water: groundwater. Extends upward from water table by surface tension in pore spaces between grains of sediment. Capillary fringe and belt of soil moisture. Water table helps to predict the productivity of wells.
