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N.M. Jackson

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

6 recordsLinked to original sources

Cost-effectiveness of the stream-gaging program in North Carolina

This report documents the results of a study of the cost-effectiveness of the stream-gaging program in North Carolina. Data uses and funding sources are identified for the 146 gaging stations currently operated in North Carolina with a budget of $777,600 (1984). As a result of the study, eleven stations are nominated for discontinuance and five for conversion from recording to partial-record status. Large parts of North Carolina 's Coastal Plain are identified as having sparse streamflow data. This sparsity should be remedied as funds become available. Efforts should also be directed toward defining the efforts of drainage improvements on local hydrology and streamflow characteristics. The average standard error of streamflow records in North Carolina is 18.6 percent. This level of accuracy could be improved without increasing cost by increasing the frequency of field visits and streamflow measurements at stations with high standard errors and reducing the frequency at stations with low standard errors. A minimum budget of $762,000 is required to operate the 146-gage program. A budget less than this does not permit proper service and maintenance of the gages and recorders. At the minimum budget, and with the optimum allocation of field visits, the average standard error is 17.6 percent.

North Carolina↗

Manual for leveling at gaging stations in North Carolina

This manual was prepared to serve several purposes in the U.S. Geological Survey North Carolina District. This manual sets forth District policy as to frequency of levels, accuracy criteria, procedures for checking the datum and setting of the various types of gages, general rules to follow in establishing the original datum of a gage, and contains sample notes to be used as guides in level notekeeping. The manual also serves as a training tool in that the reasoning behind District policy is explained and reasons are given for following the recommended techniques to assist in a better understanding of the purpose of levels and maintaining gage datum.

North Carolina↗

A technique for estimating flood heights on small streams in the city of Charlotte and Mecklenburg County, North Carolina

A method for estimating the height reached by floods having recurrence intervals of 10, 20, and 100 years is defined for unregulated streams in Charlotte and Mecklenburg County draining areas of less than 1.0 square mile. Flood heights, defined as the vertical distance between the streambed at riffles and the floodwater surface, can be used to estimate flood elevations on small streams where flood profiles and flood inundation maps are not available. An illustrative example is given of how the method can be used with streambed elevation data and topographic maps to estimate flood elevations and delineate inundated areas.

North Carolina↗

Magnitude and frequency of floods in North Carolina, technique for estimating the magnitude and frequency of floods on natural streams in North Carolina

Methods are provided to estimate the magnitude and frequency of floods on natural North Carolina streams with drainage areas greater than 0.5 square mile (1.3 square kilometers). For 257 gaged sites, the magnitudes of floods having recurrence intervals from 2 to 100 years are provided in tables. For ungaged sites, equations, graphs, and maps allow estimation of flood magnitudes. Multiple regression techniques were used to define the relation between flood peaks and seven basin and climatic variables. Drainage area is the most significant variable. Inclusion of the other six variables reduced the standard error of estimate less than 4 percent. Regression equations gave consistently different results for stations in the Coastal Plain than for stations in the mountains and Piedmont. Accordingly, stations were divided into two groups and estimating equations were developed for each geographic area.

North Carolina↗