SHYDG.FOR-Hydrograph Package for MODFLOW

SHYDG.FOR—Hydrograph Package for MODFLOW, was written for use with the USGS finite‐difference ground‐water flow model (MODFLOW). This program allows the user to specify a list of nodes where model generated heads are saved separately. The program was designed to assist in the calibration of ground‐water flow models by simplifying the process of creating hydrographs of simulated heads to compare with hydrographs of measured water levels. The program consists of two subroutines written in Fortran 77 to be added to MODFLOW and requires minor modification of the MODFLOW main program code.