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AGNPS Input Data Preparation

ARS, National Sedimentation Laboratory, Watershed Physical Processes Research Unit



AGNPS Modeling Components
Input Data Preparation
AnnAGNPS Pollutant Loading Model
Output Processing

Related Links
Water Quality Models
AGNPS References


The input data set for the AnnAGNPS Pollutant Loading Model consists of many sections of data, which can be generated by the user in a number of ways. The AGNPS Input Data Preparation Model was developed to help the user create a new, or modify an existing, AnnAGNPS data set. It is recommended that the user download, print, and read the AnnAGNPS Input Specifications in order to become familiar with the input data requirements to the pollutant loading model.

Contact: Vance Justice

Flownet Generator

This is a set of programs to assist the user to generate AnnAGNPS amorphous grids with certain stream reach characteristics (stream network, length, elevation, & slope) and cell (drainage area, elevation, aspect, land slope, & receiving reach) data. The program set consists of: (1) an existing operational computer model "TOPAGNPS"; and (2) a Fortran program to generate the DEM-related input parameters.

Contact: Vance Justice

AnnAGNPS Reference Databases

Documentation and nine reference databases are available to the user to assist with the input. They were taken directly from the HU/WQ tool and eventually will be modified to be more consistent with AnnAGNPS. The document (HU/WQ Technical Reference Manual, version 3.0.0, Chapter 3) is in a postscript format and can only be printed to a postscript printer. The "Long Name" in the data definitions of the document is the cross reference to the databases. The nine reference databases are:
AnnAGNPS Reference Database Description
Animal Waste Characteristics Reference animal waste nutrient production by animal type. Nutrient amounts are all relative to those produced by a 1,000 lb steer.
Crop Characteristics Crop type, USLE C factor, residue, leaf area index values,COD factor, yield, nutrient,growth, etc. data.
Equipment / Operations The tillage data describes the effects of the tillage operation on the surface of the ground. The tillage operation names were primarily taken from RUSLE implementation names.
Non-Crop Land Use Characteristics Similar data as crop characteristics needed for non-crop land.
Nutrient Source Characteristics Percent of: (1) elemental nitrogen & phosphorous; (2) soluble phosphorous; (3) organic phosphorous, nitrogen, & matter;nitrate, and (4) ammonia, minerialized elemental phosphorous & amonnia.
Pesticide Characteristics Pesticide data by trade name and common name. Characterizes behavior in the environment. Selected properties in the data table, by Common name, were taken from the NAPRA PPD for import to AGNPS.
Runoff Cover Conditions Runoff cover number to be used with the Runoff Curve Number Data.
Runoff Curve Number Data Runoff curve number by hydrologic soil group and the cover number from the Runoff Cover Conditions.
USLE LS Factors USLE LS factors given the land slope and length.

Contact: Phil Smith.

Climate Data Generator

For many applications, users need a continuous time stream of weather data, typically to be used as input to a computer model of some process of interest, such as water or wind erosion. A weather generator is a statistical model that can be used for this purpose. Using the ARS program GEM (Generation of weather Elements for Multiple applications), the AGNPS development team has created a version that produces output in the proper AGNPS format.

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