1. General Model Information

Name: Pesticide Registration and Enviromental Application Program

Acronym: PRE-AP

Main medium: terrestrial
Main subject: biogeochemistry, hydrology, ecotoxicology
Organization level: ecosystem
Type of model: not specified
Main application:
Keywords: pesticide transport, leaching, pesticide losses, experimental pesticides, soil layers

Contact:

Texas Agricultural Experiment Station
Blackland Research Center
808 E. Blackland Road
Temple, TX 76502

Phone: 817-770-6634
FAX: 817-770-6561
TELEX: US7401591
email: Griggs @ BRCSUN0.TAMU.EDU

Author(s):

Ray H. Griggs and Bernett Whitman
Texas Agricultural Experiment Station
Blackland Research Center

Abstract:

Purpose:
PRE-AP is a computer simulation model designed for assisting chemists, environmentalists, regulatory agencies, and agricultural chemical companies in assessing the environmental fate and transport of experimental pesticides at a very early stage of development.

PRE-AP is a shell built around the GLEAMS model and contains cropping systems for 10 major U.S. crops, a chemical parameter input editor, a graphical output analyzer and a user friendly interface. Each PRE-AP run is in essence a batch run of 15 years of site-specific weather on 20 different U.S. sites/soils that are significant for the selected crop.

GLEAMS version 1.8.55 plus volatilization, daily half-life adjustments by soil layer depending on soil temperature, moisture and pH, and Koc adjustments based on soil pH/chemical pKa/pKb relationships.

Processes Simulated:
Pesticide processes include application, runoff losses in water and soil erosion, and leaching through the soil profile. Hydrologic processes include precipitation, runoff, snowmelt, erosion, infiltration, evapotranspiration, and storage-routing through the root zone.

Input Parameters:
Pesticide properties include: water solubility, soil/water partition coefficient, Koc soil degradation half-life, date of application, and application method. Sources of soil properties include SOILS-5, and GLMSOIL. Daily weather data is generated using a version of the Weather Generator program (WGEN).

Output Parameters:
Pesticide losses through leaching or runoff and pesticide remaining in root zone. Hydrology, erosion and climate are also available outputs.

Output Flexibility: Graphical, numerical summary, and full GLEAMS available.
Graphing options are:
1) pesticide loss as a function of site-specific variable (e.g., organic matter)for 20 sites or ecosystems;
2) pesticide loss as a function of time for one specific site.

Critical Assessment:
Strengths of Model: Automated bulk processing.
Weaknesses of Model: Limitations in crop and soil environments.

Current Version No.: 1993(?)

source of abstract: ACPA Modeldatabase (04/1998)

II. Technical Information

II.1 Executables:

Operating System(s): Moderate - IBM compatible 80286 with 640K bytes RAM; MS-DOS 3.3 or higher; 30 MBytes hard disk for entire data base, math co-processor recommended; CGA or higher graphics is required for graphical display. Pre- and Post-Processors: PRE-AP is a pre- and post-processor shell linking pre-built crop, soil, and management data sets to GLEAMS. Utilizes UTIL editor (Universal Text Integration Language) for chemical parameters. Also contains "Graphical Output Analyzer".

II.2 Source-code:

Programming Language(s):

II.3 Manuals:

Dokumentation: Griggs, R.H. and J.K. Estes, undated. PRE-AP: Pesticide registration and Environmental Application Program, Texas Agricultural Experiment Station, Blackland Research Center, Temple, TX. Documentation constitutes a "what is" paper rather than a"how to use it" manual.

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

Internal Diagnostics: Basic input data ranges and order checked.

III.2.2 Output