Digital computer methods for water‐quality data

The digital computer is used on a routine basis in the ground-water program in Kansas for tasks ranging from the listing of water-quality data in tabular and publishable form to statistically and graphically analyzing a mass of data.

In the past year a number of computer programs in FORTRAN IV have been developed by Charles O. Morgan and Jesse M. McNellis using an IBM-7040 computer to store, retrieve, and manipulate water-quality data. These programs:

(1) Tabulate data at the rate of 40 chemical analyses of water per minute in a format similar to that found in the Kansas ground-water publications.

(2) Perform necessary calculations and print Stiff diagrams at the rate of 30 per minute.

(3) Perform necessary calculations and print Piper diagrams, including a square modification of the normally diamond-shaped cation-anion diagram, and trilinear diagrams of the cations and anions. The symbol representing the analyses located on the diagrams can be designated by either an analysis number or a geologic unit number. A cation-anion diagram showing the average chemical composition of water for an aquifer can also be printed. These diagrams for 50 analyses can be produced in 1.5 minutes.

(4) Plot maps of 42 individual, combined, or calculated parameters obtained from the data cards. These maps can be plotted to any specified scale and for as many as 10 designated geologic units. Computer time involved for one map with 50 plotted points is 15 seconds.

It is estimated that the use of these programs will save several man-months during a ground-water study, and the error inherent in the manual manipulation of data is greatly reduced. The present cost for running 50 analyses through the four water-quality programs on the computer is approximately $20.