i do not wait for rain. at closure i generate half of it.
.~~~~. .~~~~. .~~~~. ( )~. ( )~. ( )~. (__________) (__________) (__________) ' ' ' ' ' ' ' ' ' ' ' ' ''' ' ' ' ' ' ' ' '' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ''' '' ' ' ' ' ' ' ' ' ' ' ' ' '' ' ' ' ''' ' ' ' ' ' ' ' ''' ' '' ' .%%%%. .%%%%. .%%%%. .%%%%. .%%%%. .%%%%. .%%%&%%%%. .%%%&%%%%. .%%%&%%%%. .%%%&%%%%. .%%%&%%%%. .%%%&%%%%. %%%%%%&%%%% %%%%%%&%%%% %%%%%%&%%%% %%%%%%&%%%% %%%%%%&%%%% %%%%%%&%%%% '%%%%%%%' '%%%%%%%' '%%%%%%%' '%%%%%%%' '%%%%%%%' '%%%%%%%' || || || || || || || || || || || || /||\ /||\ /||\ /||\ /||\ /||\ ___,___,__,__,____________._,__.___,_____.___.____.__,___,_.___,_.__,_______ ~~~-~~~-~~-~~-~~-~~-~-~~~~~~~~~~~~~~-~~~~~~~-~-~~~-~~~~~~~~~~-~~-~~~~~~~~~-~ ~~~-~~~~~~~~~~~-~~-~~~~~~-~~~~-~~~~~~~-~~-~-~-~~~~-~~~~~~-~~~~~~-~~~~~~~~~~~
precipitation falls as ' and returns as ^. the return scales with canopy height.
one millimetre over one square metre is one litre. area equals the scalar, so an event on me is the scalar times its depth.
closed forest returns about half its rainfall to the atmosphere through transpiration and interception. that vapour condenses downwind and falls again. cleared ground returns nothing.
my return fraction is one half times maturity. at closure, one half. as a seed bank, zero.
| event | precipitation | interception | evapotranspiration | runoff |
|---|---|---|---|---|
| 5 mm | ||||
| 25 mm | ||||
| 60 mm |
| scalar | stratum | maturity | return fraction | evapotranspiration per 25 mm event | runoff per 25 mm event |
|---|---|---|---|---|---|
| $1,000 | floor | 0.0 % | 0.0 % | 0 L | 25,000 L |
| $10,000 | understory | 33.3 % | 16.7 % | 41,667 L | 208,333 L |
| $100,000 | canopy | 66.7 % | 33.3 % | 833,333 L | 1,666,667 L |
| $1,000,000 | emergent | 100.0 % | 50.0 % | 12,500,000 L | 12,500,000 L |
| $10,000,000 | emergent | 100.0 % | 50.0 % | 125,000,000 L | 125,000,000 L |
| now |
a drop on a leaf has three exits: evaporation from the leaf, uptake and transpiration, or runoff.
the first two are mine. the third belongs to whatever lies downstream.
| area | |
| canopy height | |
| maturity | |
| interception per 25 mm event | |
| evapotranspiration per 25 mm event | |
| runoff per 25 mm event |