juv_temp: Monthly Mean Water Temperature

Description Usage Format Details Watershed Modeling Details Source

Description

A dataset containing the monthly mean water temperature in celsius for each CVPIA watershed 1980-2000.

Usage

1

Format

dataframe with 7,440 rows and 3 variables

date

calendar date, monthly value 1980-2000

watershed

CVPIA watershed name

monthly_mean_temp_c

modeled monthly mean temperature in °C

Details

The following four methods were used to estimate the monthly mean water temperature for the watersheds during 1980-2000:

HEC-5Q
Temperature assignments were determined by Mike Wright using the input files for the three HEC-5Q runs, i.e. AR_5QCS.dat and AR_5Q-CL.OUT.

Empirical Data
Only the Lower Sacramento had sufficient measured water temperature during the period of the CVPIA salmon life cycle model. The few missing values were imputed using forecast::na.interp.

Double Regression Modeling
Data from many temperature gauges was collected from several CVPIA watersheds. In these watersheds, a double regression technique was employed to predict water temperature based on equilibrium temperature and the river mile of interest. Equilibrium temperature is the temperature a pool of water would approach if left in contact with the air for an infinite time, generally equivalent to the air temperature. The results were applied to both watersheds of origin and as surrogate data for ungauged watersheds.

Modeling Details

Additional Temperature Modeling
For streams without major dams, water temperature is highly correlated with air temperature. For each watershed not included in the HEC-5Q model that had partial water temperature data, a linear model was fitted to estimate water temperature as a function of air temperature.

Generally, the air temperature record spans both the period of the CVPIA salmon life cycle model and the complete period of record of available water temperature data. In the cases where there were missing air temperature values between 1980-2000, we imputed the missing values using forecast::na.interp in order to have a complete air temperature dataset for water temperature estimation.

Air Temperature Data Source:

Stream Water Temperature Data Sources:

Watershed Modeling Details

Source


FlowWest/cvpiaTemperature documentation built on Oct. 31, 2020, 11:28 p.m.