I have managed to successfully run the model below in Google earth engine, however the parameters
β are unknown coefficients that need to be determined through optimization based on the conditions below:
var Q = ee.Image(-1) // Value to use when none of the conditions match .where( evaluate('(Vo) <= ((Sa) - P)'), 0 ) .where( evaluate('((Sa) - P) < (Vo) < (Sa)'), evaluate('(((P - (Sa) + (Vo)) * (P - (Sa) + (2*(Vo)))) / (P - (Sa) + (2*(Vo)) + S))') ) .where( evaluate('(Sa) <= (Vo) <= ((Sa) + S)'), evaluate('( P * ( 1 - ( ( ( ( (Sa) + (S) - (Vo) ) **2) ) / ( (P * ( (Sa) + (S) - (Vo))) + ( S * (S + (Vo)) ) ) ) ) )') )
To compute the initial soil moisture
Vo and the threshold soil moisture,
Sa the following equations were used:
Vo = α√(P5*S)
Sa = βS
P5 is the 5-day antecedent rainfall and
P is the precipitation for the day.
Is there a way to achieve this in GEE?