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David J. Lystrom

Publications and source records attributed to David J. Lystrom.

5 recordsLinked to original sources

ESTIMATION OF URBAN STORM-RUNOFF LOADS.

The United States was divided into three regions, on the basis of mean annual rainfall, to decrease the variability in storm-runoff constituent loads and to improve regression relations with basin and climatic characteristics. Multiple-regression analyses, in progress, are being refined to determine the best regression models for each of the storm-runoff constituent loads in each of the three regions. These techniques, when finalized, can be used to estimate storm-runoff constituent loads for gaged and ungaged urban watersheds. The preliminary standard errors of estimate for five constituents examined to date ranged from 54 to 223 percent, and the coefficients of determination (r**2) ranged from 0. 39 to 0. 94. Total storm rainfall and total contributing drainage area appear to be the most significant independent variables in the regression models. This paper is a progress report on preliminary results of estimating storm-runoff constituent loads for ungaged watersheds.

Conference Paper↗

Regional analysis of the effects of land use on stream-water quality; methodology and application in the Susquehanna River Basin, Pennsylvania and New York

A framework is presented for compiling available data for assessing statistical relationships between water quality and climate, physiography and land use. Seventeen water-quality characteristics studied represent annual mean concentrations or calculated annual yields of suspended sediment, dissolved solids and various chemical species of nitrogen and phosphorus. Usable multiple-linear regressions were developed relating water-quality characteristics to basin characteristics for 14 of the 17 water-quality characteristics with standard errors of estimate ranging from 17 to 75 percent. These models can be used to estimate water quality at specific stream sites or to simulate the generalized effect of land-use characteristics on water quality. For example, observed nitrate yields were up to 20 times greater than the simulated background yields. This increase is indicated to be the result of chemical fertilizers, animal wastes, and urbanization. It was concluded that this was a viable method of assessing the relationships between water quality and basin characteristics on a regional basis. (Woodard-USGS)

Water-Resources Investigations Report↗

Definition of regional relationships between dissolved solids and specific conductance, Susquehanna River basin, Pennsylvania and New York

This report presents statistical tests for assessing the accuracy and validity of two regional models of the relationship between dissolved-solids concentration and specific conductance. These models are used to estimate dissolved-solids concentrations based on specific-conductance measurements. The two regional models are compared with station models for 27 stream sites in the Susquehanna River basin. The average standard errors of estimate of two regional models, when used to estimate dissolved-solids concentrations for the 27 stream sites, are 10.7 and 10.6 percent. In comparison, the station models have average standard errors of 9.0 and 9.3 percent, respectively. Results of the statistical tests indicate that in the Susquehanna River basin the regional models can be used to estimate dissolved-solids concentrations from specific-conductance data for sites for which chemical analyses are not available.

New York, Pennsylvania↗

Analysis of potential errors in real-time streamflow data and methods of data verification by digital computer

The magnitude, frequency, and types of errors inherent in real-time streamflow data are presented in part I. It was found that real-time data are generally less accurate than are historical data, primarily because real-time data are often used before errors can be detected and corrections applied. Various methods of verifying real-time streamflow data are outlined in part II. Relatively large errors (those greater than 20-30 percent) can be detected readily by use of well-designed verification programs for a digital computer, and smaller errors can be detected only by discharge measurements and field observations. The capability to substitute a simulated discharge value for missing or erroneous data is incorporated in some of the verification routines described. The routines represent concepts ranging from basic statistical comparisons to complex watershed modeling and provide a selection from which real-time data users can choose a suitable level of verification.

Open-File Report↗