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Geology topics

J.F. Turner

Publications and source records attributed to J.F. Turner.

5 recordsLinked to original sources
USGS1980

Evaluation of remote hydrologic data-acquisition systems, west-central Florida

The study provides an evaluation of the hydrologic applications of a land-line and two satellite data-relay systems operated during 1977-78 in the Southwest Florida Water Management District. These systems were tested to evaluate operational and reliability characteristics. Telephone lines were used to relay data in the land-line system, and the Geostationary Operational Environmental Satellite (GOES) and Land satellite (Landsat) were used in the satellite system. The land-line system was tested for 15 months at a streamflow site. Accurate data were obtained 94% of the time during the test period. Data losses were attributed to telephone-line interference, low-battery voltage, and vandalism. The GOES system was tested at a rainfall site for 17 months. During this period, 79% of the transmissions received from the station were relayed by the GOES system to the U.S. Geological Survey computer, resulting in successful processing of 88% of all possible rainfall observations. On the average, seven data transmissions were completed each day. The Landsat system was tested at a rainfall site for about 17 months and for about 8 months at a streamflow site. During these periods of operation, only about 2% of all data observations for the stations were successfully relayed by the Landsat system to the U.S. Geological Survey computer. An average of about three data transmissions was completed each day for each site. (USGS).

Florida↗
USGS1979

Streamflow simulation studies of the Hillsborough, Alafia, and Anclote Rivers, west-central Florida

A modified version of the Georgia Tech Watershed Model was applied for the purpose of flow simulation in three large river basins of west- central Florida. The model was calibrated for six streamflow stations located in these basins using 4 years of historical and current rainfall, runoff, and estimated evapotranspiration data. Watersheds modeled range in size from about 70 to 650 square miles. Calibrations were evaluated by comparing the following synthesized and observed data: annual hydrographs for the 1959, 1960, 1973 and 1974 water years, flood hydrographs (maximum daily discharge and flood volume), and long-term annual flood-peak discharges (1950-72). Annual hydrographs, excluding the 1973 water year, were compared using average absolute error in annual runoff and daily flows and correlation coefficients of monthly and daily flows. For stations used in the study, average absolute errors in simulated runoff range from 9 to 21 percent and errors in daily flows range from 48 to 71 percent. Correlation coefficients for monthly flows range from 0.81 to 0.95 and correlation coefficients for daily flows range from 0.68 to 0.87. Correlation coefficients for simulated and observed maximum daily discharges and flood volumes used for calibration range from 0.91 to 0.98 and average standard errors of estimate range from 18 to 45 percent. Cor-relation coefficients for simulated and observed annual flood-peak dis-charges range from 0.60 to 0.74 and average standard errors of estimate range from 33 to 44 percent. The number of flood events used for calibration varies for each streamflow station, but range from 6 to 18. The number of annual flood-peak discharges used also vary but average about 20 for each station. On the basis of these results, it is concluded that flood calibrations have been achieved for stations used in this study; however, because of data limitations, calibrations and prediction errors cannot be completely verified until additional rainfall, runoff, and evapotranspiration data become available.

Florida↗
USGS1978

Magnitude and frequency of flooding on the Myakka River, Southwest Florida

Myakka River is a coastal stream that drains approximately 550 square miles in southwest Florida. Under natural conditions, Tatum Sawgrass, a large depression, served as a flood overflow area for the upper part of the Myakka River basin. A recently constructed (1974) dike system across the lower part of Tatum Sawgrass has reduced previously available storage, thereby affecting downstream flooding. An evaluation of the effects of Tatum Sawgrass dikes on flooding indi-cates that flood-peak discharges and flood heights having recurrence inter-vals of up to 25 years are increased. As a result, about 1,200 additional acres along Myakka River main stem may be inundated during 2-year flood conditions. Maximum effects include a 19 percent increase in flood-peak discharge at State Road 780 and a 0.8 foot increase in flood height near the downstream end of the study reach. Floods having recurrence intervals of 50 years or greater will over-top dikes and the storage capacity of Tatum Sawgrass will revert to natural condition capacity. As part of the evaluation, diked condition flood profiles, having recurrence intervals of 2, 5, 10, 25, 50, 100, 200, and 500 years were determined for the nontidal part of a 45-mile reach of Myakka River main stem, Clay Gully, and Blackburn Canal. These data indicate that Clay Gully flood water will overflow embankments at State Road 780 during the 2-year flood and will overflow the bridge on State Road 780 during the 25-year flood. Myakka River flood water will overflow embankments at State Road 72 and Border Road during 100-year flood conditions and at State Road 780 during 500-year conditions.

Florida↗
USGS1966

Evaporation study in a humid region, Lake Michie, North Carolina

The mass-transfer and water-budget techniques of calibrating a reservoir for evaporation were evaluated through a study of Lake Michie, N.C. The techniques appear adequate for estimation of lake evaporation and net seepage in humid regions where lake storage is affected by streamflow and ground-water seepage, under conditions no more adverse than those affecting Lake Michie. The analysis of 25 months of mass-transfer and water-budget data collected at Lake Michie indicates pronounced seasonal variation in both evaporation and seepage.

North Carolina↗