Boxmodels; Equation of Continuity ; Residence time or flushing time
a simple example:
Take 40 gallon tank,
fill it at the rate of 4 gph (gallons per hour)
answer ...................
(p.s what was the question? ..................................................)
mathematically:
N
t fill =
---------
dN/dt
plot TIME
on
horizontal
axis,
% FILLED
on
vertical
axis
What happens when tank is full but tap still running? ..........................................
at what rate? .....................................
steady state conditions: N (t+1)= N (t+2)= N (t+n)......................... dNi/dt= dNo/dt
expanding, use sum of all inputs equals sum of all outputs
Box Model
of n
ESTUARY
Land left
Sea right plot R=riverflow, O=outflow, I=inflow
and
show
equation of
continuity ( ..... = ... + .... )
and saltwedge