A small catchment absorbs a mean daily radiation energy flux
Rn= 4200 W m-2during the month of
August. Apply the energy balance approach to estimate
evapotranspiration from the catchment during the month of
August.
- Write a complete energy balance equation (include all terms)
for the catchment for the month of August.
- Neglecting conduction to the ground (G) and the change
in energy stored, simplify your energy balance equation for the
catchment so that it can be solved for the latent heat flux,
El. Also, replace the term H (the sensible heat
flux) with B*El(whereB is the Bowen
ratio.
- Using a mean Bowen ratio of 0.24 for the catchment, calculate
the mean daily flux of latent heat to the atmosphere (W
m-2) and mean evapotranspiration rate (mm
day-1)-3from the catchment. Use a water
density, ρw= 995 kg m.
- Calculate the total evapotranspiration from the catchment
during the month of August.