Calibrating the Soquel-Aptos PRMS Model to Streamflow Data Using PEST Cameron Tana Georgina King HydroMetrics Water Resources Inc. California Water Environmental and Modeling Forum 2015 Annual Meeting Program March 10, 2015
Presentation Outline Study Purpose PRMS Model Model Input Data PEST Model Calibration Model Results
Study Purpose Develop a tool to estimate rainfall vs. deep groundwater recharge relationship Be able to examine how deep groundwater recharge changes spatially and over time Develop information that can be used to determine drought curtailment criteria
Precipitation-Runoff Modeling System (PRMS) USGS developed modeling system Distributed-parameter, physically based hydrologic model USGS provided support and assistance developing the Soquel-Aptos model
Model Input Data Develop Hydrologic Response Units (HRU) HRU attributes Land use Soils Vegetation type Canopy cover Climate data Precipitation Maximum and minimum temperature Model period from Water Year 1984 through Water Year 2009
Groundwater Reservoir Stream and/or Groundwater Reservoir Soil-Zone Reservoir Stream and/or Soil-Zone Reservoir PRMS HRU Components Solar Radiation and Fluxes Evaporation Sublimation Precipitation Air temperature Plant Canopy Interception Evaporation & Transpiration Throughfall Throughfall Snow Pack Throughfall Evaporation Snowmelt Surface runoff Upslope Flow Impervious-Zone Reservoir Fast and Slow Interflow Soil-Zone Reservoir Groundwater Recharge Upslope Flow Groundwater Reservoir Groundwater flow Groundwater Sink Elements and text in light gray are part of PRMS but were not used in the Soquel-Aptos PRMS model
How HRUs are Delineated NRCS Watersheds GIS Watersheds Aquifer Outcrops Land Use "J "J + U + U + U + U + U + "J U Gages + U
Primary Spatial Layers HRU Parameters and Attributes calculated from Primary Layer DEM Aspect Slope Elevation Land Cover Cover Type Root Depth Winter Rain Interception Summer Rain Interception % Impervious SSURGO Soil depth Available Water Content % Clay % Sand Canopy Density Summer Density Winter Density Spatial HRU Parameters PRMS Parameter HRU Attribute HRU parameters from a combination of attributes and parameters Root Depth Minimum of Soil Depth Rooting Depth Product of Available Water Content Rooting Depth Minimum of 18 x AWC Average of % Clay % Sand Rooting Depth Soil Moisture Maximum Soil Recharge Maximum Soil Type Aspect Elevation Max Temperature Adjustment Min Temperature Adjustment Air Temperature Coefficient for Evapotranspiration For details on calculations, see: wwwbrr.cr.usgs.gov/projects/sw_mows/software/gsflow_s/input_instructions/modelattributes/hruattributes.htm
Stepwise Model Calibration Manual calibration Solar radiation Potential evapotranspiration Calibration with PEST Streamflow Steps recommended by USGS
Solar Radiation PRMS calculates solar radiation for each HRU Based on slope, aspect, and day of year Calibrate monthly relationship between air temperature and solar radiation Calibrate to mean monthly solar radiation at local CIMIS station
Potential Evapotranspiration PRMS calculates using modified Jensen-Haise Based on air temperature and solar radiation Calibrate monthly Jensen-Haise coefficient Due to lack of local data, calibrated to mean monthly values from PET maps by National Weather Service
Streamflow 10 gages
Groundwater Reservoir Stream and/or Groundwater Reservoir Soil-Zone Reservoir Stream and/or Soil-Zone Reservoir Calibrate Soil Zone Parameters 15 Parameters Recommended by USGS Coefficients for flow routing Storage capacities Percentage area contributing to runoff Evaporation & Transpiration Evaporation Upslope Flow Soil-Zone Reservoir Impervious-Zone Reservoir Surface runoff Fast and Slow Interflow Groundwater Recharge Upslope Flow Groundwater Reservoir Groundwater flow Groundwater Sink
Grouping by Geology Calibration Zones Group 1 2 3 4 HARDROCK(4) PURISIMA (2) Undifferentiated PURISIMA (3) AROMAS (1)
The PEST Model (Batch File) PAR2PAR PRMS TSPROC
Calibrate Soil Zone Parameters PAR2PAR Translates Zone Based Parameter Values to HRU Parameter Values Creates HRU Based PRMS Input PRMS TSPROC
Calibration to Streamflow PAR2PAR PRMS TSPROC Process Streamflow Timeseries Data Daily Mean annual Monthly mean Mean monthly Nash-Sutcliffe
Daily Calibration Plots from PRMS Gage 5 Red = Measured Blue = Simulated Gage 8 Green = Measured Yellow = Simulated
Daily Calibration Data from PRMS Gage 5 Red = Measured Blue = Simulated Gage 8 Green = Measured Yellow = Simulated
Mean Annual Flow Rate "J 1 +U +U 4 3 "J 2 +U 5 +U 6 910 +U "J +U 7 +U 8
Model Calibration Monthly Mean Mean Monthly "J 1 +U +U 4 3 "J 2 +U 5 +U 6 910 +U "J +U 7 +U 8
Monthly Mean Flow Rate Calibration Statistics Mean Error = -0.4 Absolute Mean Error = 3.7 Standard Deviation = 8.7 Standard Deviation/Range = 1%
Nash-Sutcliffe Goodness of Fit Gage NS < 0 1 1989 2 1985, 1987, 1994 3 none 4 none 5 none 6 1985 7 1988 8 1988, 1994 9 1985, 1992 10 NA
Nash-Sutcliffe Goodness of Fit One day causes NS < 0 Removing one day, moves 1989 NS to 0.4
Model Results 4 Purisima Aquifer 2 3 1 P a c i f i c O c e a n Aromas Aquifer Purisima = 51 miles 2 Aromas = 14 miles 2 All units in Acre-Feet per Year
4 Year Deep Recharge, acre-feet Drought Curtailment Criteria Based on recharge shortfall estimated from 3 year rainfall totals, SqCWD declared Stage 3 drought curtailment in 2014 120,000 100,000 Santa Cruz Stn Identified False Positive Allowable Shortfall Unidentified 97 in. 80,000 thru 2/15 60,000 40,000 20,000 0 Stage 4 40 50 60 70 80 90 100 110 120 130 4 Year Rainfall through March
Acknowledgements Soquel Creek Water District Central Water District City of Santa Cruz US Geological Survey