Model:LOADEST
LOADEST
Introduction
History
Papers
LOADEST Questionnaire
Contact Information
| Model: | LOADEST |
| Contact person: | Rob Runkel |
| Institute: | U.S. Geological Survey |
| City: | -- |
| Country: | United Kingdom |
| Email: | runkel@usgs.gov |
| 2nd person involved: | -- |
| 3rd person involved: | -- |
Model description
| Model type: | Single model for the terrestrial and the coastal domain. |
| Description: | LOAD ESTimator (LOADEST) is a FORTRAN program for estimating constituent loads in streams and rivers. Given a time series of streamflow, additional data variables, and constituent concentration, LOADEST assists the user in developing a regression model for the estimation of constituent load (calibration). Explanatory variables within the regression model include various functions of streamflow, decimal time, and additional user-specified data variables. The formulated regression model then is used to estimate loads over a user-specified time interval (estimation). Mean load estimates, standard errors, and 95 percent confidence intervals are developed on a monthly and(or) seasonal basis.
The calibration and estimation procedures within LOADEST are based on three statistical estimation methods. The first two methods, Adjusted Maximum Likelihood Estimation (AMLE) and Maximum Likelihood Estimation (MLE), are appropriate when the calibration model errors (residuals) are normally distributed. Of the two, AMLE is the method of choice when the calibration data set (time series of streamflow, additional data variables, and concentration) contains censored data. The third method, Least Absolute Deviation (LAD), is an alternative to maximum likelihood estimation when the residuals are not normally distributed. LOADEST output includes diagnostic tests and warnings to assist the user in determining the appropriate estimation method and in interpreting the estimated loads. The LOADEST software and related materials (data and documentation) are made available by the U.S. Geological Survey (USGS) to be used in the public interest and the advancement of science. You may, without any fee or cost, use, copy, modify, or distribute this software, and any derivative works thereof, and its supporting documentation, subject to the USGS software User's Rights Notice. |
Technical information
| Supported platforms: | Linux, Unix, Windows |
| Programming language: | Fortran77 |
| Model development started at: | 2001 and ended in 2005 |
| To what degree will the model become available: | Source code will be available, and model can be used as well as a teaching tool and executable will be available. |
| Current license type: | U.S. Government software product |
| Memory requirements: | -- |
| Typical run time: | -- |
Input / Output description
| Input parameters: | Given a time series of streamflow, additional data variables, and constituent concentration, LOADEST assists the user in developing a regression model for the estimation of constituent load (calibration). |
| Input format: | ASCII |
| Output parameters: | Estimated constituent loads |
| Output format: | ASCII |
| Post-processing software (if needed): | no, see see http://water.usgs.gov/software/loadest/faq/ |
| Visualization software (if needed): | no |
Process description
| Processes represented by model: | -- |
| Key physical parameters & equations: | -- |
| Length scale & resolution constraints: | -- |
| Time scale & resolution constraints: | -- |
| Numerical limitations and issues : | -- |
Testing
| Available calibration data sets: | -- |
| Available test data sets: | See applications described in software documentation http://water.usgs.gov/software/loadest/doc/ |
| Ideal data for testing: | -- |
User groups
| Currently or plans for collaborating with: | -- |
Documentation
| Key papers of the model: | http://water.usgs.gov/software/loadest/apps/ |
| Is there a manual available: | yes |
| Model website if any: | http://water.usgs.gov/software/loadest/ |
Additional comments
| Comments: | http://water.usgs.gov/software/loadest/ |
