PREWet - Pollutant Estimates for Wetlands


Identification Information

Model Title

Pollutant Removal Estimates for Wetlands (PREWet)

Version of Model

2.3

Responsible Party of Model

Compound

 

Responsible Party Individual Name

Mark S. Dortch

 

Organization Affiliated with Responsible Party

US Army Corps of Engineers - Waterway Experiment Station

 

Position Name of Responsible Party

Supervisory Research Civil Engineer, Water Quality and Contaminant Modeling Branch

 

Responsible Party Contact Information

Compound

 

 

Delivery Point

US Army Corps of Engineers

 

 

 

Waterways Experiment Station

 

 

 

3909 Halls Ferry Road

 

 

City

Vicksburg

 

 

Administrative Area

MS

 

 

Postal Code

39180-6199

 

 

Country

United States of America

 

 

Telephone Number

(601) 634-3517

 

 

Electronic mail Address

dortchm@wes.army.mil

 

 

Facsimile Number

(601) 634-3517 Ex. 3219

 

 

Responsible Party Individual Name

Jeffrey A. Gerald

 

Organization Affiliated with Responsible Party

ASCI, Inc.

 

Position Name of Responsible Party

Engineer

 

Responsible Party Contact Information

Compound

 

 

Delivery Point

ASCI, Inc.

 

 

 

1365 Beverly Road

 

 

City

McLean

 

 

Administrative Area

VA

 

 

Postal Code

22101

 

 

Country

United States of America

Date of Creation

September, 2000

Model Citation

Dortch, M. S. and J. A. Gerald (2000). Pollutant Removal Estimates for Wetlands (PREWet),Ver2.3. Vicksburg, VA, United States of America, US Army Corps of Engineers.

 

Intended Use

Application Purpose

004 - Public Administration

 

005 - Research

 

Description

Conceptual Model Description

The pollutant removal for wetlands (PREWet) screening model was designed with the objective of estimating the removal efficiency for a specific pollutant by a wetland given a limited amount of basic information about the wetland. The model is a screening-level assessment that uses simplified quantitative methods that minimize time and effort for the end user.

Model Typology

008 - Algebraic Equations

Field of Study

0603 - Conservation

 

0605 - Ecology

 

0612 - Hydrology

 

0699 - Other Earth Science

Other Field of Study

Hydrologic Pollutant Removal

Keywords

Hydrologic Pollutant Removal, Wetlands, Water Filtration, Water Quality

Source of Additional Information

Compound

 

Additional Information Text

Dortch, M. S. and J. A. Gerald (1995). Screening-Level Model for Estimating Pollutant Removal by Wetlands, US Army Corps of Engineers - Waterways Experiment Station. Report No.WRP-CP-9

 

 

Dortch, M.S. 1996. "Removal of Solids, Nitrogen, and Phosphorus in the Cache River Wetland," Wetlands, 16(3), 358-365.

 

 

Kadlec, R.H. and R.L. Knight, 1996. Treatment Wetlands. Lewis Publ., CRC Press, BocaRaton, FL, USA.

 

Additional Information URL Address

http://www.wes.army.mil/el/elmodels/pdf/wrp-cp-9.pdf

 

Access and Availability

Access or Use Constraints

003 - Available after registry

Availability Contact

Compound

 

Availability Contact Individual Name

Mark S. Dortch

 

Organization Affiliated with Availability Contact

US Army Corps of Engineers - Waterway Experiment Station

 

Position Name of Availability Contact

Supervisory Research Civil Engineer, Water Quality and Contaminant Modeling Branch

 

Availability Contact Information

Compound

 

 

Delivery Point

US Army Corps of Engineers

 

 

 

Waterways Experiment Station

 

 

 

3909 Halls Ferry Road

 

 

City

Vicksburg

 

 

Administrative Area

MS

 

 

Postal Code

39180-6199

 

 

Country

United States of America

 

 

Electronic Mail Address

dortchm@wes.army.mil

 

 

Telephone Number

(601) 634-3517

 

 

Facsimile Number

(601) 634-3517 Ex. 3219

Ordering or Access Procedure

The model is free to download after registration from the following Internet Address: http://www.wes.army.mil/El/elmodels/index.html#wqmodels

Cost of Model

No cost involved

 

System Requirements

Hardware Requirements

The program is a protected-mode DOS program that requires a computer with a minimum of an 80386 central processor, with at least two megabytes of random excess memory. The files necessary for using the program are PREWET.EXE, DOS4GW.EXE, and PREWET.DAT, which must be located in the same directory. The program creates temporary tiles while executing; therefore, there should be sufficient hard disk space available. The output files created by the program are RE.OUT and any file specified by the user to save as an input file. The file RE. OUT is created for any run that the user has selected with the Run Model button. This tile can be viewed or printed after exiting the program and contains the summary of the userís session showing input parameters and the calculated removal efficiencies.

Software Requirements

any DOS operating system

Operating System

Windows

Expertise Required

Compound

 

Expertise to Obtain

Basic understanding of .ftp server downloading procedures.

 

Expertise to Run

Basic computational mouse and keyboard operation techniques, Understanding of wetland properties and water pollutant types.

 

Expertise to Interpret

Basic understanding of pollutant filtration results.

 

Input Data Requirements

Input Data Extent and Resolution

Compound

 

Minimum Spatial Resolution

Watershed coverage

 

Spatial Extent

Watershed coverage

 

Spatial Resolution and Extent Explanation

The model is designed to specify the filtration properties of an entire watershed. The size of the watershed can be specified in terms of volume, area, depth, length, or width.

 

Temporal Resolution

0.1 days

 

Temporal Resolution and Extent Explanation

The hydrologic residence time (in days) of water in the watershed is derived by the volumetric values specified. The detention time (in days) is calculated using the mean velocity of flow (in cm/s) and the spatial gradients (longitudinal gradients or fully mixed).

Input Data File

http://www.wes.army.mil/El/elmodels/pdf/wrp-cp-9.pdf (Chapter 4 of the PDF formatted report)

 

Data Processing

Programming Language

C++

Algorithmic Representation

The equations used in the model are available in the report available from the following address: http://www.wes.army.mil/El/elmodels/pdf/wrp-cp-9.pdf

Iterative Cycles

The model is not designed to accommodate iterative cycles.

 

Model Output

Output Documentation

http://www.wes.army.mil/El/elmodels/pdf/wrp-cp-9.pdf (Chapter 4 of the PDF formatted report)

Output Comment

The model is designed to determine the outflow of the following hydrologic contaminant: Total Suspended Solids (TSS), Total Coliform bacteria (TCB), Biochemical Oxygen Demand (BOD), Total Nitrogen, Total Phosphorus, and "Contaminants (organic chemicals and trace metals).

 

Calibration Efforts and Validation

Calibration Efforts

PREWET was tested against TP, TN, and 1SS data obtained from the Cache River wetland. The model performed well for the Cache River application where RE predictions were within 15 percent of RE estimates obtained for a 3-year period of observations. Similar long-term data sets were not available for testing the other model variables (i. e., BOD, TCB, and contaminants). However, recommendations are provided for estimating rate constants needed to compute RE for each of these constituents. As with any new model, additional applications are needed to gain a better understanding of the modelís strengths and limitations.

Current Use or Application

Dortch, MS 1996. "Removal of Solids, Nitrogen, and Phosphorus in the Cache River Wetland," Wetlands, 16(3), 358-365.

Strengths and Weaknesses

The total phosphorus removal rate coefficient can be either specified by the user or computed from first principles (given the appropriate input information). Please be aware of the assumptions used in developing the algorithm for computing the phosphorus (TP) removal rate coefficient in PREWet. This algorithm is based on the assumption that the growth and death of aquatic plants have no net effect on the long-term removal of TP. The justification for this is that plants take up P when they grow, but recycle it when they die. So for steady-state conditions, there is no net effect. TP is assumed to partition only between water and solids, and its fate is affected by settling of suspended solids, resuspension of sediment, diffusion of sediment pore water, and sediment burial. A steady-state mass balance for the water column and sediment bed is used to derive the relationship of TP removal rate to these processes. The above approach is probably adequate for most forested wetlands, such as the Cache River w

 

Metadata Source

Metadata Creation Date

5 November, 2001

Metadata Responsible Party

Compound

 

Metadata Responsible Party Individual Name

Scott J. Crosier

 

Organization Affiliated with Metadata Responsible Party

University of California, Santa Barbara

 

Position Name of Metadata Responsible Party

Graduate Student, Geography Dept.

 

Role of Responsible Party

Creator

 

Metadata Responsible Party Contact Information

Compound

 

 

Delivery Point

University of California, Santa Barbara

 

 

 

3510 Phelps Hall

 

 

City

Santa Barbara

 

 

Administrative Area

CA

 

 

Postal Code

93106-4060

 

 

Country

Unites States of America

 

 

Electronic Mail Address

scott@geog.ucsb.edu

 

 

Telephone Number

(805) 893-2714

 

 

Facsimile Number

(805) 893-8617

Metadata Source of Information

Dortch, M. S. and J. A. Gerald (1995). Screening-Level Model for Estimating Pollutant Removal by Wetlands, US Army Corps of Engineers - Waterways Experiment Station. Report No.WRP-CP-9

 

Dortch, M. S. and J. A. Gerald (2000). Pollutant Removal Estimates for Wetlands (PREWet),Ver2.3. Vicksburg, VA, United States of America, US Army Corps of Engineers.

Metadata Standard Name and Version

Alexandria Digital Earth Prototype, Metadata for Models Working Group, Content Standard for Computational Models, version 1.2 (2001)



Last Updated on 11/5/01
By Scott Crosier