Geology topics
J. M. Norris
Publications and source records attributed to J. M. Norris.
Surface water-quality characteristics in the upper North Fork Gunnison River basin, Colorado
Analyses of water quality data collected during 1982 and 1983 in the upper North Fork Gunnison River basin indicate that dissolved-solids concentrations are relatively small, with a mean value near 97 milligrams per liter. Most major dissolved constituents also had small measured concentrations throughout the study area. Trace-element concentrations generally were small; however, total-iron concentration generally was large in the area with a mean concentration of about 8,250 micrograms per liter. The cause of this larger iron concentration probably is related to the local geology. Paonia Reservoir, located on Muddy Creek, greatly reduced suspended-sediment and trace-element concentrations. The reservoir had only a slight effect on major dissolved-constituent concentrations. Analyses of alkalinity, sulfate, and dissolved-solids concentrations indicated that little, if any, changes in water quality occur as a result of coal mining; however, more data are needed to make more definite conclusions. Sulfate concentrations increased slightly downstream through the mined area; however, with the small concentrations measured and limited quantity of data, the source of the increased sulfate could not be determined. (USGS)
Application of the precipitation-runoff modeling system to small basins in the Parachute Creek basin, Colorado
The U.S. Geological Survey 's Precipitation-Runoff Modeling System was calibrated and verified for two small basins in western Colorado. Average monthly mean, average monthly maximum, average annual total, and average daily mean observed and model predicted streamflow differences were small, on the average < 10 %, indicating the Precipitation-Runoff Modeling System can, when adequately calibrated, satisfactorily estimate these streamflow factors. Average monthly minimum streamflow generally was over-predicted, but actual differences between observed and model predicted average monthly minimum streamflow are small. To determine relative errors of streamflow prediction in ungaged basins, three different model parameter sets were used to predict streamflow in a nearby gaged basin. The first set of parameters was based on the assumption that little information about this basin was available. Model parameters used to calibrate basins approximately 75 mi away were adjusted to model this basin on the basis of easily obtainable physical basin characteristics, such as elevation and slope. The second set of parameters was based on the first set, except it was assumed that local climate information was available to estimate the model 's climatic parameters for the basin better. The second set of parameters improved streamflow estimation in this basin by about 7% over the first model parameter set. The third set of model parameters assumed that the model had been calibrated to similar, nearby basins. This model parameter set was derived from the model parameters of the earlier calibrated basins. Using these calibrated model parameter values improved streamflow estimates by approximately 21% over the second parameter set. The average difference between observed and predicted average annual streamflow for the basin using these parameters was 16.3%. For comparison, the average difference between observed and predicted average annual total streamflow for the calibration basins was 12.9%. This suggests that, with some increase in error, this model can be used to estimate streamflow in ungaged basins, if the model has been calibrated to a nearby gaged basin with similar physical characteristics. (Lantz-PTT)
Calibration procedure for a daily flow model of small watersheds with snowmelt runoff in the Green River coal region of Colorado
A calibration procedure was developed for the U.S. Geological Survey 's Precipitation-Runoff Modeling System for watersheds in which snowmelt is the major contributor to runoff. The model uses daily values of air temperature and precipitation as input and the output is mean daily discharge. The procedure appears sufficient to calibrate both streamflow volume and the timing of mean daily discharge if other model parameters are reasonably estimated. Model structure and sensitivity analysis suggest that one of the most important parameters is the available water-holding capacity of the soil (SMAX). Changing this parameter through a series of iterations, the calibration procedure minimizes the error between observed and predicted annual discharge. The calibration suggests that the single parameter SMAX may be sufficient for optimizing both the volumes and the timing of runoff, assuming other model parameters are adequately estimated. Additional optimization on parameters sensitive to timing does not appear to improve prediction. This indicates that these parameters were estimated accurately prior to calibration. Further investigation is needed on more watersheds to determine SMAX 's ability to calibrate volume and timing with a constant set of other model parameter values.
Simulated effects of anticipated coal mining on dissolved solids in selected tributaries of the Yampa River, northwestern Colorado
Identifying cumulative effects of coal mining on dissolved solids downstream from multipe coal-mining operations is particularly important in western basins. The problem of identifying cumulative effects is evident in the Trout Creek drainage, a tributary to the Yampa River in northwestern Colorado, where a number of mines are active and mine expansions are planned. As an evaluation tool, a model was developed and calibrated for the Trout Creek drainage and a reach of the Yampa River main stem. This model uses a series of nodes on the stream network to sum water quantity and quality through the network. The model operates on a monthly basis and uses data from water years 1976 to 1981. Output is mean monthly discharge, dissolved-solids concentration, and dissolved-solids load. Observed data are needed to initiate the model and for model calibration. Some data were extrapolated from records of nearby streamflow-gaging stations. Some nodes within the stream network were for inputs from anticipated mining and were inactive during calibrations. After calibration, these nodes were used to input water discharge at a given dissolved-solids concentration to reflect various future mine configurations. (USGS)