Willmott, Cort J.2017-02-092017-02-091977http://udspace.udel.edu/handle/19716/2048755 pages : illustrations ; 28 cm.The computer program described is designed for use in a variety of problems, and requires a minimum amount of input information. Every effort was made to make the code transparent, so that it could be easily modified should additional or alternative computations be desired. Currently the program uses the Thornthwaite (1948) method for calculating potential evapotranspiration; the subroutines where the estimates are made may be replaced by another method. The advantages of WATBUG over most previously published water budget programs include: (1) budgets can be computed on a monthly or daily basis; (2) records of monthly budgets up to 40 years and daily budgets up to one year can be repeated to 'balance the budget'; (3) all relationships are explicitly specified so that 'look-up' tables are not required; (4) the program is easily modified; and (5) multiple budgets may be done in a single run. The program requires that periods of time evaluated as a single budget be consecutive. A variety of multi-annual monthly and daily data sets were used to test all WATBUG's options. Hand computations made for comparison with the results of each test run were in agreement within a mm or two.FORTRAN IV (Computer program language)Water balanceWATBUGUnited StatesClimateClimatology -- Computer programs.Report