I want to estimate sensitivity of evapotranspiration (ET) to meteorological variable (ex. temperature, wind speed etc.).
Equation for Sensitivity Coefficient is:
S = (change in ET/change in X)*(X/ET)
where S is sensitivity coefficient
Change in X is the relative change of model input value X and change in ET is the relative change in ET induced by change in X.
In this equation, how were calculated the change in ET and change in meteorological variable. Is it month to month change or something else? Can anyone help me in this regard?
Dear Aarti,
The equation for sensitivity equation is only based on the derivative (here of ET versus wind). You can plot the function ET(X) by varying X and look at the derivative partial ET over partial X. Then compute with some corresponding mean values of ET and X to obtain your sensitivity coef.... a standard equation study! The computation is similar for obtaining error for multivariable functions.
Hope this can help you.
Hi Aarti,
Do the derivatives exist?
Please consider: http://tinyurl.com/jbdtcg9
Similar concerns exist with partial derivatives. You may want to take a peek at: http://tinyurl.com/jbdtcg9
For fun, you may want to take a look at: http://tinyurl.com/ztwuwb5
Best regards,
Jack
Sensitivity is often performed on a model that fitted. You can fit a statistical model that relates ET with other variables. Then you can use the estimated coefficients to calculate sensitivity.
Other method is to fit ET equations and simulate the process. Then you could perform sensitivity on it by a small change the X value and quantifying change. in Y.
- Badges
- Science topic
- Similar topics
- Geoscience
- Hydrology