OHD/HL/HSMB - Hydrology Group

Physically-Based Enhancements to SAC-SMA

Two significant enhancements have been made to the Sacramento Soil Moisture Accounting (SAC-SMA) model. First, a physically based algorithm has been added to model the impacts of frozen soil on the precipitation-runoff process. This new model is called the heat transfer version, or SAC-HT. SAC-HT also generates physically-based soil moisture and soil temperature estimates. The following report provides details of this new approach:

NOAA Technical Report NWS 52     Physically-Based Modifications to the Sacramento Soil Moisture Accounting Model: Modeling the Effects of Frozen Ground on the Rainfall-Runoff Process

Second, the evapotranspiration physics from the Noah land surface model have been added to the SAC-HT model. This new model is called the SAC-HTET. The following report provides details of this new approach:

NOAA Technical Report NWS 53     Modification of Sacramento Soil Moisture Accounting Heat Transfer Component (SAC-HT) for Enhanced Evapotranspiration