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D.R. Johnson

Publications and source records attributed to D.R. Johnson.

7 recordsLinked to original sources
USGS1999

Effectiveness of an existing estuarine no-take fish sanctuary within the Kennedy Space Center, Florida

Approximately 22% of the waters of the Merritt Island National Wildlife Refuge, which encompasses the Kennedy Space Center, Florida, have been closed to public access and fishing since 1962. These closed areas offer an opportunity to test the effectiveness of “no-take” sanctuaries by analyzing two replicated estuarine areas. Areas open and closed to fishing were sampled from Nov 1986 to Jan 1990 with 653 random trammel-net sets, each enclosing 3,721 m 2 . Samples from no-fishing areas had significantly (P < 0.05) greater abundance and larger fishes than fished areas. Relative abundance (standardized catch per unit effort, CPUE) in protected areas (6.4 fish/set) was 2.6 times greater than in the fished areas (2.4 fish/set) for total game fish, 2.4 times greater for spotted seatrout Cynoscion nebulosus , 6.3 times greater for red drum Sciaenops ocellatus, 12.8 times greater for black drum Pogonias cromis , 5.3 times greater for common snook Centropomus undecimalis , and 2.6 times greater for striped mullet Mugil cephalus . Fishing had the primary effect on CPUE, independent of habitat and other environmental factors. Salinity and depth were important secondary factors affecting CPUE, followed by season or month, and temperature. The importance of specific factors varied with each species. Median and maximum size of red drum, spotted seatrout, black drum, and striped mullet were also significantly greater in the unfished areas. More and larger fish of spawning age were observed in the unfished areas for red drum, spotted seatrout, and black drum. Tagging studies documented export of important sport fish from protected areas to fished areas.

Florida↗
USGS1996

Synthesis of monthly natural flows for selected sites in the Musselshell River basin, Montana, base period 1929-89

Synthesized monthly natural streamflows were required at 13 sites for use in a streamflow- accounting model to evaluate the effects of various water-allocation schemes on water availability in the Musselshell River Basin in central Montana. Records of monthly streamflow at 14 streamflow-gaging stations were used to synthesize monthly natural flows at tributaries and the 13 synthesis sites. A streamflow-record extension program was used to extend flow records at the 14 gaged sites to a common base period, 1929-89. To synthesize monthly natural flows at 10 sites on the Musselshell River mainstem, synthesized monthly natural flows at all signi- ficant tributary streams were required. Results from a previous study were used to synthesize tributary natural flows. Monthly natural flows at each mainstem site downstream from the first site were synthesized by successively adding monthly natural flows from intervening tributaries to the next upstream mainstem site. Special methods using extended-record flows from gaged tributaries were used to synthesize monthly natural flows at three tributary sites. Synthesized mean annual natural flows were found to be greater than mean annual extended-record flows at three selected comparison sites on the Musselshell River. The differences between mean natural and extended-record flows (depletions) at Harlowton and Musselshell were considered to be reasonable given the amount of irrigated acreage upstream from the two sites. The differences at Mosby, the site farthest downstream, was less than at Musselshell, the next upstream site, indicating that the methods of synthesis had error. The synthesis error generally was attributed to the larger natural variability of tributary flows in the lower portion of the Musselshell River Basin.

Water-Resources Investigations Report↗
USGS1995

Simulated monthly hydrologic data and estimated flood characteristics for Cherry Creek at a proposed reservoir site near Terry, Montana

Methods used to simulate a monthly hydrologic budget for water years 1937-92 for the proposed Cherry Creek Reservoir (maximum volume about 14,100 acre-feet) are described and monthly results of the simulation are presented. The budget is based on recorded and estimated streamflow, precipitation, evaporation, and estimated reservoir seepage. The budget also includes water diversions from the Yellowstone River whenever the reservoir depth was less than 20 feet (minimum operating level of 2,260 feet) and outflows whenever the reservoir elevation exceeded a maximum operating level of 2,290 feet. Monthly suspended sediment and dissolved-solids concentrations in the reservoir were estimated from regression relations between logarithms of concentration and streamflow for Cherry Creek and for the Yellowstone River near Sidney, Montana. The results of the reservoir simulation indicate that flows from Cherry Creek, an intermittent stream having a drainage area of about 360 square miles, generally were adequate to maintain the reservoir elevation above the minimum operating level if no seepage loss occurred. With a seepage loss of 3 cubic feet per second, flow diversions from the Yellowstone River were required for 34 percent of the months to maintain the reservoir elevation at minimum operating level. The reservoir elevation generally was maintained near maximum operating level for a seepage loss of 0 cubic feet per second, but generally was close to minimum operating level for a seepage loss of 3 cubic feet per second. Cumulative sediment deposition for the 56-year period was estimated to be about 138 acre-feet from Cherry Creek alone and only slightly more (149 acre-feet) when additional water was imported from the Yellowstone River. The simulated concentration of dissolved solids in the reservoir showed a slightly increasing trend over time, interrupted by several large decreases, for no reservoir seepage loss. The maximum concentration for no seepage loss reached a maximum value of about 2,500 milligrams per liter in 1982. For a seepage loss of 3 cubic feet per second, water was imported from the Yellowstone River, and the concentration generally ranged from about 500 to about 1,200 milligrams per liter throughout the period. Flood hydrographs and volumes for flood discharges having 25-, 50-, and 100-year recurrence intervals were estimated from synthetic 24-hour duration storms having total storm depths with recurrence intervals of 25, 50, and 100 years. These synthetic storms were used in a rainfall-runoff model (HEC-1) based on the Clark unit-hydrograph method to develop flood hydrographs from which volumes were computed. The peak discharges of the 25-, 50-, and 100-year flood hydrographs determined from the rainfallrunoff model compared closely to the 25-, 50-, and 100-year peak discharges determined from regional equations developed by the U. S. Geological Survey. The volume of the 100-year hydrograph developed from the HEC-1 model was about 11,250 acre-feet.

Montana↗
USGS1994

Estimates of monthly streamflow characteristics and dominant-discharge hydrographs for selected sites in the lower Missouri and Little Missouri River basins in Montana

Various streamflow characteristics were estimated for water-reservation purposes for 17 sites in the lower Missouri River Basin and four sites in the Little Missouri River Basin in Montana. The characteristics were mean monthly and annual streamflow and monthly mean streamflow that is exceeded 90, 80, 50, and 20 percent of the time. In addition, dominant-discharge hydrographs were estimated for 10 of the 17 sites in the lower Missouri River Basin and for four sites in the Little Missouri River Basin. Dominant discharge was considered to be equal to the peak discharge having a recurrence interval of two years. Monthly streamflow characteristics generally were based on a common 1937-86 base period. A mixed-station record-extension program was used to estimate missing flow data for streamflow-gaging stations. Two methods were used to estimate characteristics at ungaged sites. One method was based on corre- lating discharge measurements at the estimating site with concurrent discharges at a nearby gaged site. The second method was based on using a drainage-area ratio to transfer characteristics at a gaged site to the estimating site. Dominant discharges for gaged sites were obtained from a previous flood-frequency report or by fitting a log-Pearson Type 3 probability distribution to recorded peak-flow data. A drainage-area-ratio adjustment was used to transfer dominant dis- charges from gaged sites to ungaged sites. Dominant-discharge hydrographs were determined from visual examination of recorded hydrographs having maximum daily discharges that were relatively close to the estimated dominant discharges.

Water-Resources Investigations Report↗
USGS1989

Estimates of monthly streamflow characteristics at selected sites in the upper Missouri River basin, Montana, base period water years 1937-86

Estimates of streamflow characteristics (monthly mean flow that is exceeded 90, 80, 50, and 20 percent of the time for all years of record and mean monthly flow) were made and are presented in tabular form for 312 sites in the Missouri River basin in Montana. Short-term gaged records were extended to the base period of water years 1937-86, and were used to estimate monthly streamflow characteristics at 100 sites. Data from 47 gaged sites were used in regression analysis relating the streamflow characteristics to basin characteristics and to active-channel width. The basin-characteristics equations, with standard errors of 35% to 97%, were used to estimate streamflow characteristics at 179 ungaged sites. The channel-width equations, with standard errors of 36% to 103%, were used to estimate characteristics at 138 ungaged sites. Streamflow measurements were correlated with concurrent streamflows at nearby gaged sites to estimate streamflow characteristics at 139 ungaged sites. In a test using 20 pairs of gages, the standard errors ranged from 31% to 111%. At 139 ungaged sites, the estimates from two or more of the methods were weighted and combined in accordance with the variance of individual methods. When estimates from three methods were combined the standard errors ranged from 24% to 63 %. A drainage-area-ratio adjustment method was used to estimate monthly streamflow characteristics at seven ungaged sites. The reliability of the drainage-area-ratio adjustment method was estimated to be about equal to that of the basin-characteristics method. The estimate were checked for reliability. Estimates of monthly streamflow characteristics from gaged records were considered to be most reliable, and estimates at sites with actual flow record from 1937-86 were considered to be completely reliable (zero error). Weighted-average estimates were considered to be the most reliable estimates made at ungaged sites. (USGS)

Water-Resources Investigations Report↗
USGS1989

Estimates of mean monthly streamflow for selected sites in the Musselshell River basin, Montana, base period water years 1937-86

Estimates of mean monthly and mean annual streamflow were made for 56 selected sites in the Musselshell River basin and 1 site outside the basin. The study area was divided into a Mountain Region and a Plains Region and the estimation methods were applied separately in the two regions. Four methods were developed to estimate mean monthly streamflow at ungaged sites. The first method was based on the regression relation between mean monthly streamflow and various basin and climatic characteristics. The standard errors ranged from 35 to 71% in the Mountain Region and from 98 to 157% in the Plains Region. The second method was based on the regression relations between mean monthly streamflow and active-channel width. The standard errors ranged from 38 to 81% in the Mountain Region and from 71 to 98% in the Plains Region. The third method was based on correlation of measured streamflow at ungaged sites with concurrent daily mean streamflow at nearby gaged sites. The standard errors ranged from 36 to 66% in the Mountain Region and from 109 to 321% in the Plains Region. The fourth method, generally the most reliable, estimated mean monthly streamflows by weighing individual estimates in accordance with their variance and degree of independence. The standard error for this method when all three individual estimates were weighed ranged from 25 to 55% in the Mountain Region and from 71 to 97% in the Plains Region. (USGS)

Water-Resources Investigations Report↗