ePTM

Criterion

Explanation

General Description

The ePTM adds juvenile salmon swimming behavior and predation mortality to the DSM2 PTM. Apart from these additions, the ePTM linearly interpolates all hydraulic and hydrodynamic quantities between DSM2 HYDRO timesteps to account for simulated juvenile salmon (SJS) movement within an ePTM time substep. Broadly, the scope of the ePTM can be summarized into its representation of the hydrodynamics, the fish behavior, and the mortality of SJS.

Model Domain

Same domain as DSM2

Developer

NMFS-SWFSC, NMFS-NWFSC, QEDA Consulting, UC-Santa Cruz

Hardware computing requirements

Not specified

Code language

Java

Original application

Sub-model of NMFS Winter Run Life Cycle Model (WRLCM)

Public/proprietary and cost

N/A

Physically or empirically based

Physical and empirical

Mathematical methods used

Linear interpolation of all hydraulic and hydrodynamic quantities between DSM2 HYDRO timesteps. Simulated juvenile salmon movement is modeled as a Weiner process. The XT model is used for predator-induced mortality.

When running simulations, 1000 simulated juvenile salmon (SJS) are released uniformly each month at Sacramento and in the floodplain node. The survival probability of each SJS escaping the Delta at Chipps Island is resampled with replacement to produce 1000 survival probabilities. A similar exercise is carried out for Delta fry and smolts with 100 simulated salmon released uniformly over all the nodes within the North and Central Delta corridor, which results in more than 15,000 SJS released over all release nodes.

Input data requirements

Requires outputs from DSM2 HYDRO and Delta Habitat Capacity Model

Outputs

The primary output is survival to Chipps Island on a monthly time step.

Pre-processing and post-processing tools

No processing tools provided

Representation of uncertainty

The ePTM is a stochastic model, but parameter uncertainty is only incorporated in swimming speed.

Prevalence

High profile modeling effort involving collaboration of government agencies, universities, and consultants. No peer-reviewed publications. Used in WaterFix.

Ease of use for public entities

Ease of obtaining information and availability of technical support

No formal user group and no commercial help desk

Source code availability

N/A

Status of model development

Model is under active development. The next update of ePTM will include a CSTR model for flooded islands as well as a parameterization of simulated juvenile salmon movement at channel junctions based on fitting beta distributions to observed juvenile salmon distributions at key junctions in the Delta. NMFS and USBR host workshops to address questions about the model structure and capabilities.

Challenges for integration

The ePTM is currently an example of an integrated model because it depends on outputs of DSM2 and Delta Habitat Capacity Model and the outputs of the ePTM are used by the WRLCM. The primary challenge for integration with other models is that the ePTM is under active development and not generally accessible to modelers outside of the core development team.