EOS-0002 Lecture Notes - Lecture 4: Evapotranspiration, Piezometer, Pressure Head

• School: Tufts University
• Department: Earth and Ocean Sciences
• Course: EOS-0002
• Professor: Jack Ridge

Document Summary

Surface water - channel and sheet flow: flows downhill, air p=1 atm everywhere in a stream, controls: elevation and momentum. Groundwater - saturated flow: flows up and down, very slow momentum (insignificant differences, controls: elevation and pressure differences. Energy - potential energy from elevation, or pressure. Bernoulli"s equation - calculates energy at a point in a fluid. Simplified to remove constants (density of water, air pressure) Reduced to give head values: distance values that tell pressure. Pressure head at water table defined as 0. Drainage basin budget - p=et + q + sgw (evapotranspiration, storage of groundwater) Head - total head h = z + p. Z is elevation head from a datum at zero (sea level normally) P is pressure head from the point to the water table (height of water column)