David J Holtschlag, PStat (Former Employee)

This report documents the results of a study of the cost effectiveness of the stream-gaging program in Michigan. Data uses and funding sources were identified for the 129 continuous gaging stations being operated in Michigan as of 1984. One gaging station was identified as having insufficient reason to continue its operation. Several stations were identified for reactivation, should...

This report contains 17,607 miscellaneous stream discharge measurements made at 2,897 sites in Michigan. An average of 515 measurements were made each year from 1960 through 1984; most of these were made from April through October of each year. Miscellaneous measurements include periodic and occasional measurements of streamflow at sites where systematic records are unavailable.

This report gives the results of an investigation to determine the chemical and physical characteristics of ground and surface water in Van Buren County and to relate these characteristics to the agricultural use of land. Chemical inputs to the hydrologic system, including those from precipitation, animal wastes, septic tanks, and fertilizers, are assessed. Land-use, geologic setting...

Multiple-regression equations were developed to estimate flow characteristics at ungaged sites. Several readily measureable basin characteristics and an areal adjustment factor are required in the equations. Equations have been prepared to estimate mean and mean monthly flow, flow duration, low flow, peak flow, and flood volume. The precision of the flow estimate varies with the flow

Current estimates of station skew indicate that estimates of generalized skew obtained from the skew map of the United States prepared by the U.S. Water Resources Council have a -0.27 bias for Michigan. Station skew was recomputed using currently recommended statistical procedures of the Water Resources Council, and available data through 1982. Generalized skew is combined with station...

An unsteady-flow simulation model was applied to a 19.5-mile reach of Saginaw River. The model provides a method of determining instantaneous discharge for flows from -8,000 to 12,000 cubic feet per second. The currently used slope-rating method can be utilized to compute discharge only under steady and high-flow conditions. Unsteady flow frequently occurs in the Saginaw River as a...