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Geography: Water Resources

This guide provides geography resources for Texas State University students, faculty, and staff.

Recommended Books for Water Resources Classes

Important Terminology

  • Digital Orthophoto Quarter Quads (DOQQ) - digital aerial images produced by the USGS. They contain orthorectified aerial photography at a resolution of 1 meter.

  • Drainage Basin - Regions or areas bounded by drainage divides and occupied by drainage systems; specifically the tract of country that gathers water originating as precipitation and contributes it to a particular stream channel or system of channels, or to a lake, reservoir, or other body of water. (Definition Source)

  • Chronostratigraphic Units - "A body of rocks that includes all rocks formed during a specific interval of geologic time, and only those rocks formed during that time span. Chronostratigraphic units are bounded by synchronous horizons.The rank and relative magnitude of the units in the chronostratigraphic hierarchy are a function of the length of the time interval that their rocks subtend, rather than of their physical thickness" (Definition Source).

  • Koppen Climate - "the most widespread system used to classify the climates of places on our planet. The system was developed German climatologist and amateur botanist Wladimir Köppen (1846-1940) who divided the world's climates into several major categories based upon general temperature profile related to latitude." (Definition Source)

  • PET (Potential Evapotranspiration) - Potential sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. (Wikipedia Entry)

  • Penman Equation - The Penman equation describes evaporation (E) from an open water surface, and was developed by Howard Penman in 1948. Penman's equation requires daily mean temperature, wind speed, air pressure, and solar radiation to predict E. (From Wikipedia)

  • Thornthwaite Equation -  An equation to calculate PET.  "The amount of evaporation that would occur if a sufficient water source were available. If the actual evapotranspiration is considered the net result of atmospheric demand for moisture from a surface and the ability of the surface to supply moisture, then PET is a measure of the demand side." (Wikipedia Entry)