About SWASH

General Information

SWASH is the acronym of Surface WAter Scenarios Help. It is a user-friendly software shell, developed to perform the so-called Step 3 FOCUS runs for the FOCUS Surface Water Scenarios. It was developed by Alterra, in close co-operation with W!SL, the Wageningen Software Labs, both located in Wageningen, the Netherlands.

The SWASH development team consists of (in alphabetical order):
Erik Van den Berg (Alterra)
Johnny te Roller (W!SL)
Mechteld ter Horst (Alterra)
Paulien Adriaanse (Alterra)

The SWASH Developers co-operated with the developers of the various tools that are linked to the SWASH shell. These are:

Short Model Description

Main functions of SWASH

SWASH is an overall user-friendly shell, encompassing a number of individual tools and models, involved in Step 3 calculations for the FOCUS Surface Water Scenarios. Its main functions are:

  1. Maintenance of a central pesticides properties database for use in MACRO, PRZM and TOXSWA
  2. Preparation of other input for MACRO, PRZM and TOXSWA, notably application patterns, application methods and dosages
  3. Creation of projects, containing all Step 3 FOCUS runs required for use of a pesticide on a specified crop
  4. Calculation of spray drift deposition onto ditch, stream and pond like waterbodies
  5. Provision of an overview of crop and waterbody combinations in each scenario, of the extent of each scenario and of the installed versions of each model, including its shell and database.

Short description of the SWASH software package

SWASH is aimed to create and link the runs of the various models in an easy and consistent way. With the exception of the Drift Calculator SWASH does not perform any model simulations, so the user should run himself the MACRO, PRZM and TOXSWA models. First pesticide entries via spray drift and drainage or runoff/erosion need to be simulated. This is done by the Drift Calculator (embedded in SWASH), and the MACRO or PRZM model, respectively. Next TOXSWA simulates the behaviour of the pesticide in the FOCUS water bodies. Pesticides can enter the waterbody by two entry routes only: spray drift plus either drainage or runoff.

See the following figure, illustrating the sequence of tools and models used to calculate pesticide exposure in the Step 3 EU FOCUS Surface Water Scenarios.

The SWASH User Interface was developed as a user-friendly environment for preparing input for the FOCUS models and make them communicate in a robust way. The interface is an integrated environment for data storage, data retrieval, drift deposition calculations and calling of models.

SWASH, MACRO, PRZM and TOXSWA must be installed in an agreed directory structure to enable the communication between the various models. The user interface is linked to a relational database for easy data access. It reads and writes data into one of the MACRO databases and reads and writes several input files for PRZM. TOXSWA makes use of the SWASH database. The FOCUS input is stored and locked in the SWASH database. The user can generate an overview of all needed runs for a desired compound-crop combination with a FOCUS wizard.

Role and Place in FOCUS scenarios calculation

SWASH is designed for Step 3 FOCUS runs and the FOCUS Surface Water Scenarios Working Group recommends the user to perform all Step 3 FOCUS runs with SWASH, i.e. to always have SWASH prepare input for all FOCUS runs and start the individual models via SWASH. The FOCUS wizard in SWASH prepares projects composed of runs for all valid crop-scenario-waterbody type combinations, while the user-defined wizard allows the user to make a selection out of these FOCUS combinations.

The SWASH tool may also be useful for refined risk assessment calculations of Step 4 by editting the input files prepared by SWASH outside the shells of the MACRO, PRZM and TOXSWA models.

Current use outside FOCUS

The SWASH tool was designed for Step 3 calculations for the FOCUS Surface Water Scenarios. It is also useful for Step 4 calculations for the FOCUS Surface Water Scenarios. No use outside FOCUS has been foreseen.

Excerpt of existing model documentation