| A | B |
| water budget | a description of "incoming" and "outgoing" water of an area |
| precipitation (P) | "incoming" water added to the soil |
| potential evapotranspiration (Ep) | "outgoing" water removed from the soil; depends on temperature |
| climate ratio | P/Ep = a comparison of all the incoming and outgoing water for an area |
| recharge | when water is added to the soil for storage |
| surplus | when more precipitation falls than is used by plants, animals, humans->FLOOD |
| usage | when stored water is needed and is taken from the ground |
| deficit | when need for water is greater than rainfall, and soil's water is gone-> DROUGHT |