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M. N. Landers

Publications and source records attributed to M. N. Landers.

9 recordsLinked to original sources
USGS2013

Measuring suspended sediment

Suspended sediment in streams and rivers can be measured using traditional instruments and techniques and (or) surrogate technologies. The former, as described herein, consists primarily of both manually deployed isokinetic samplers and their deployment protocols developed by the Federal Interagency Sedimentation Project. They are used on all continents other than Antarctica. The reliability of the typically spatially rich but temporally sparse data produced by traditional means is supported by a broad base of scientific literature since 1940. However, the suspended sediment surrogate technologies described herein – based on hydroacoustic, nephelometric, laser, and pressure difference principles – tend to produce temporally rich but in some cases spatially sparse datasets. The value of temporally rich data in the accuracy of continuous sediment-discharge records is hard to overstate, in part because such data can often overcome the shortcomings of poor spatial coverage. Coupled with calibration data produced by traditional means, surrogate technologies show considerable promise toward providing the fluvial sediment data needed to increase and bring more consistency to sediment-discharge measurements worldwide.

Book chapter↗
USGS1991

Flood characteristics of Mississippi streams

Flood magnitudes for selected recurrence intervals from 2 to 500 years were determined for 330 gaged sites in the study area where annual peak-flow records have been collected. The principal study area is Mississippi; however, selected data collected in adjoining States on streams draining into or from Mississippi are also included, flood frequency at a gaged stream site is defined by fitting the Pearson Type III probability distribution to the log-transformed annual peaks. The accuracy of the flood frequency determined for a gaged site is determined primarily by the number of years of annual peak-flow record (the sample size). Greater accuracy is achieved in the current analysis than in previous analyses because of the additional years of annual peak-flow record. Flood-frequency and basin characteristics at gaged sites were used to develop regression equations for estimating flood frequency where annual peak-flow records are not available. Flood frequency for ungaged stream sites in Mississippi may be estimated using basin characteristics in regression equations. Regression equations were computed using the generalized-least-squares procedure rather than the ordinary-least-squares procedure used in previous regional hydrologic analyses. The generalized-least-squares procedure considers the variable error of the gaging station flood frequencies and corrects for the cross-correlation of concurrent annual peaks. When the gaging stations in the sample for regression analysis have widely varying record lengths and concurrent peak flows, which are correlated between sites, the generalizedleast-squares procedure provides more accurate estimates of the regression coefficients and model error than does the ordinary-least-squares procedure. These flood-frequency equations provide managers with improved tools for estimating flood frequencies for purposes of management and design.

Mississippi↗
USGS1989

Regionalization of flood characteristics

Regionalization procedures are used to transfer flood characteristics from gaged to ungaged locations. These procedures are an extension of the gaging network that allows planners and designers to make estimates of flood frequency at ungaged sites of interest. The U.S. Geological Survey has a long time involvement in the development of these regionalization procedures. This paper describes the evolution of these regionalization procedures from the index-flood procedure used in the 1940's to the multiple regression procedure based on generalized least squares that is currently being used.

Conference Paper↗
USGS1987

EFFECTS OF LAND SUBSIDENCE ON FLOOD PROFILES.

In this study, the effects of land subsidence on water-surface elevation and depth profiles during flood conditions were investigated for a large, hypothetical, slope-controlled stream. Subsidence depressions, with a range of vertical magnitudes and areas were imposed on a hypothetical stream reach. Step-backwater computations were made to determine water-surface and depth profiles for a large hypothetical flood. Changes in the water-surface and depth profiles were related to the assumed subsidence to determine relative effects on flood profiles. The results may be useful in understanding and evaluating flood hazards where subsidence coincides with the flood plain of a large, upland stream.

Conference Paper↗
USGS1985

Development and testing of highway storm-sewer flow measurement and recording system

A comprehensive study and development of measuring instruments and techniques for measuring all components of flow in a storm-sewer drainage system was undertaken by the U.S. Geological Survey under the sponsorship of the Federal Highway Administration. The study involved laboratory and field calibration and testing of measuring flumes, pipe insert meters, weirs, electromagnetic velocity meters as well as the development and calibration of pneumatic-bubbler pressure transducer head measuring systems. Tracer-dilution and acoustic flow meter measurements were used in field verification tests. A single micrologger was used to record data from all the above instruments as well as from a tipping-bucket rain gage and also to activate on command the electromagnetic velocity meter and tracer-dilution systems. (Author 's abstract)

Water-Resources Investigations Report↗