7.8 - What is the Difference Between Monthly and Daily Consumptive Use Analysis?

The crop consumptive use methods employed in the program and the interface are the Modified Blaney-Criddle, the Original Blaney-Criddle, and the Pochop (for bluegrass only) methods with calculations on a monthly basis and the ASCE Standardized Penman-Monteith method with calculations on a daily basis. The monthly consumptive use methods require average monthly temperature and frost dates. The ASCE Standardized Penman-Monteith method requires daily maximum temperature, minimum temperature, wind speed, solar radiation, and vapor pressure. Other crop consumptive use methods available when the FORTRAN program is operated independently of the interface include the Penman-Monteith and the Modified Hargreaves methods, operated on a daily time step.

The results of a monthly consumptive use analysis are summarized in several files including the *.obc and the *.cir output files, while the results of the ASCE Standardized Penman-Monteith method are summarized in the *.opm and *.cir output files. The StateCU GUI does not allow the user to perform a monthly and daily analysis in the same scenario. However, the Time Series Data Tool can be used to compare results from a monthly and daily analysis by opening the respective binary (*.bd1) output files and selecting the climate station or structure name and data type.