1. John Walton Fall, 2010

6. Grows over shallow water table areas High amount of evapotranspiration Water balance component Q out of reach = Q into reach + Groundwater inputs + Surface runoff -evaporation – transpiration - human use Solve water balance for groundwater input

7. Assume steady state system where groundwater recharge equals discharge Take measured surface water flows and diversions Estimate ET from Salt Cedar/Mesquite/cane bosque area Divide groundwater input by drainage basin area to obtain large scale groundwater recharge rates Answer: ~ 1 cm/year

11. The potential difference between electrodes placed in the ground is measured. When an electric current is passed between two electrodes placed outside the measurement electrodes a potential difference is created. Deeper penetration of the electrical field occurs as the electrodes are spaced further apart. Interpretation of this data can be complex in some cases