Wind Speed

Wind speed is required by SWAT+ when the Penman-Monteith equation is used to calculate potential evapotranspiration. Mean daily wind speed is generated in SWAT+ using a modified exponential equation:

$\mu _{10m}=\mu wnd_{mon}*(-ln(rnd_1))^{0.3}$ 1.3.6.1

where $\mu _{10m}$ is the mean wind speed for the day (m s$^{-1}$), $\mu wnd_{mon}$ is the average wind speed for the month (m s$^{-1}$), and $rnd_1$ is a random number between 0.0 and 1.0.

Table 1:3-6: SWAT+ input variables that pertain to generation of wind speed.

Variable Name	Definition	File Name
WNDSIM	Wind speed input code: 1-measured, 2-generated	file.cio
WNDAV(mon)	$\mu wnd_{mon}$: Average wind speed in month (m/s)	.wgn