Stochastic Empirical Loading and Dilution Model (SELDM) Transportation Research Board Presentation

Science Center Objects

Note: SELDM is now on version 1.0.3 Please use the new version on the software support page here

The U.S. Geological Survey (USGS) presented information on SELDM at the 93rd Annual Meeting of the Transportation Research Board, (TRB) in cooperation with the Federal Highway Administration (FHWA). This web page provides links to a FHWA fact sheet on the model, a copy of the TRB paper, and the SELDM presentation in several formats.


  Fact sheet:The Stochastic Empirical Loading and Dilution Model (SELDM)--The new Federal Highway Administration runoff-quality model

  Proceedings paper:The Stochastic Empirical Loading and Dilution Model (SELDM) for analysis of flows, concentrations, and loads of highway runoff constituents

Abstract: The Stochastic Empirical Loading and Dilution Model (SELDM) was developed by the U.S. Geological Survey in cooperation with the Federal Highway Administration (FHWA) to supersede use of the 1990 FHWA runoff-quality model. SELDM is designed to be a tool that can be used to transform disparate and complex scientific data into meaningful information about the risk for adverse effects of runoff on receiving waters, the potential need for mitigation measures, and the potential effectiveness of such measures for reducing these risks. SELDM is easy to use because much of the information and data needed to run SELDM are embedded in the model and are obtained by defining the location of the site of interest and five simple basin properties. Information and data from thousands of sites across the country were compiled to facilitate use of SELDM. Use of SELDM for doing the types of sensitivity analyses needed to properly assess water-quality risks are provided in a case study. For example, use of deterministic values to model upstream stormflows instead of representative variations in prestorm flow and runoff may substantially overestimate the proportion of highway runoff in downstream flows. Also, risks for total phosphorus excursions are substantially affected by the selected criteria and the modeling methods used. For example, if a single deterministic concentration rather than a stochastic population of values is used to model upstream concentrations, then the percentage of water-quality excursions in the downstream receiving waters may depend entirely on the selected upstream concentration.


On-Line Presentation

This on-line presentation, which is about 18 minutes in duration, provides an overview of the model and a case study. Several formats are available for use with different computer and browser configurations. The script file provides the text-narration for each slide for the hearing impaired.

 Notes pages with script: GranatoJonesSELDMscript.pdf

 Download Zip file with MP4 format: (41,307 KB)

 Download stand-alone executable-file format: ggranatoJonesSELDM.exe (15,671 KB)

 Spring 2015 Webex
 Webex Slides: WebexIntroSpring2015v1.0.pdf