Geology topics

Research about Uvas Creek

Source-linked reports with geographic coverage including Uvas Creek.

3 recordsLinked to original sources

USGS1984

Results of a solute transport experiment at Uvas Creek, September 1972, California

A 3-hour constant-rate injection of chloride, strontium, and sodium was made into Uvas Creek, Santa Clara County, California, to determine solute transport and sorption properties of a small stream. Seven observation stations were selected within a 635-m reach of the stream where water samples were collected before, during and after the injection. Size-sorted stream sediments placed in the stream prior to the injection were sampled to determine sediment sorption properties. Dissolved solute concentration data are presented in both original and normalized forms to illustrate the different transport properties of the three solutes. Sorbed concentrations are tabulated as a function of both time and grain size. Calculations of streamflow and sorptive distribution coefficient are given.

California↗

USGS1984

Low-flow transport models for conservative and sorbed solutes — Uvas Creek, near Morgan Hill, California

Models describing low-flow transport of conservative (nonreactive) and reactive solutes, which adsorb on the streambed, are developed and tested. Temporary storage within the bed plays an important role in solute movement. Three different models of bed-storage processes are developed for conservative solutes. One model assumes the bed is a well-mixed, nondiffusing, nonreacting zone. Solute flux into the bed is then proportional to the difference between stream and bed-solute concentrations. A second model assumes that solute is transported within the bed by a vertical diffusion process. The bed-solute concentration, which matches the stream concentration at the interface, varies with depth in the bed according to Fick 's law. A third model assumes convection in the downstream direction occurs in certain parts of the bed, while the mechanism of the first model functions elsewhere. Storage of absorbing species is assumed to occur by equilibrium adsorption within streambed particles. Uptake rate is described by an intraparticle diffusion process. Model equations were solved using finite element numerical methods. Models were calibrated using data from a 24-hour injection of conservative chloride and adsorptive Sr ions at Uvas Creek near Morgan Hill, California. All models predict well except for some overestimation by the adsorption model during dieaway.

California↗

USGS1976

Solute transport and modeling of water quality in a small stream

An injection of chloride, sodium, and stable strontium was made at a constant rate for 3 hours into Uvas Creek, Santa Clara County, Calif., to determine the mass transport processes in a small stream. Five observation points were selected within a 610-metre reach of the stream below the injection site. Water samples were collected at the observation points during and immediately after the injection. A mathematical model of the stream was obtained by solving analytically and optimally the one-dimensional mass transport equation of the solutes in the stream. Comparison of field results with a simplified mathematical model indicates the dominance of convection in the behavior of sodium and chloride. The concentration of chloride and sodium can be closely simulated by the model. However, strontium cannot be well represented by the simplified model, which contains a first-order decay-type sink.

California↗