SSTEMP is a much-scaled down version of the Stream Network Temperature Model (SNTEMP) by
Theurer et al. (1984). SSTEMP may be used to evaluate alternative reservoir release proposals, analyze
the effects of changing riparian shade or the physical features of a stream, and examine the effects of
different stream withdrawals and returns on instream temperature. Unlike the large network model,
SNTEMP, this program handles only single stream segments for a single time period (e.g., month, week,
day) for any given “run”. Initially designed as a training tool, SSTEMP may be used satisfactorily for a
variety of simple cases that one might face on a day-to-day basis. It is especially useful to perform
sensitivity and uncertainty analysis.
The program requires inputs describing the average stream geometry, as well as (steady-state) hydrology
and meteorology, and stream shading. SSTEMP optionally estimates the combined topographic and
vegetative shade as well as solar radiation penetrating the water. It then predicts the mean daily water
temperatures at specified distances downstream. It also estimates the daily maximum and minimum
temperatures, and unlike SNTEMP, handles the special case of a dam with steady-state release at the
upstream end of the segment.
With good quality input data, SSTEMP should faithfully reproduce mean daily water temperatures
throughout a stream reach. If it does not, there is a research opportunity to explain why not. One should
not expect too much from SSTEMP if the input values are of poor quality or if the modeler has not
adhered to the model’s assumptions.