water balance Flashcards
what is water balance
difference between inputs and outputs in the drainage basin
positive v negative water balance
precipitation exceeds runoff and evapotranspiration = positive = water stores inc
runoff and evap exceed precipitation = negative= dec stores
winter seasonal pattern
high rain
low evap
high storage
high runoff as inc rain and dec evap
surplus
summer seasonal patterns
low rain
high evap
low storage
low runoff as low rain and inc evap
defecit
what is soil moisture budget
change in vol water stored in soil over yr
factors of soil moisture budget
rain
potential evapotranspiration
temp - more evap and air hold more
soil moisture recharge
water added to soil by rainfall or potentially irrigation
soil moisture utilisation
soil water used by plants
soil moisture defecit
little water
plants wilt and die
soil moisture surplus
more water available than can be used by plants
summer soil moisture budget
plants grow
soil moisture utilisation + defecit
high evap
autumn soil moisture
cooling down
plants dying
less evap
winter soil moisture budget
soil moisture recharge
plants dormant
spring soil moisture budget
surplus
