WAM was developed by SWET and has been in use by both private and public sectors for over 15 years.  The first WAM GIS based interface was developed before commercially available GIS software was even available, which resulted in SWET developing its own version of a GIS.  Since then WAM has been upgraded to work as an extension in the ESRI software platform.  This extension was originally built into the ArcVIEW 3.2 environment, and was recently upgraded to a fully compatible .NET framework that operates as an series of "dockable" windows and tools inside of the ArcGIS platform.

WAM has been linked to other hydrologic and constituent transport models to provide additional capabilities and specificities.  These linkages have been used in various projects, espacially for the development of TMDL's in Florida.  Please review the WAM projects pages for specific details.

SWET’s Watershed Assessment Model is being integrated into NASA’s Coastal On-line Assessment and Synthesis Tool (COAST). By merging these tools the end user will be able to implement BMP’s to hydrology and water quality responses on water being discharged into coastal waters within the COAST Interface. SWET is working with NASA to create a conceptual design report for the “area of interest” tool and the COAST/WAM Tool.   The tools created will provide data transfer and operational protocols for the COAST environment.

The Everglades Agricultural Area (EAA) is a an important agricultural region that covers about 500,000 ac to the southeast of Lake Okeechobee and to the north of the Everglades system.  The area has primarily flat organic soils with naturally high water tables (Histosols).  When these Histosols are drained for agriculture, aerobic mineralization releases both phosphorus (P) and nitrogen (N) from the organic matter.  The nutrient loss from these soils is of concern to the downstream Everglades ecosystem, since it can cause vegetation changes through eutrophication, especially in an oligotrophic system like the Everglades.

EAAMOD was developed to test the effectiveness of BMPs for reducing the P losses from EAA farms, and to evaluate the long-term effects of various BMPs at the field and farm scale.

In the EAA, an organic topsoil covers the marl bedrock, and is often separated by an impeding layer.  Water content and redox potential change with depth, affecting phosphorus mineralization and partitioning.  The marl layer has a high affinity for P as indicated by the low P concentration of drainage water from ditches penetrating this layer.  Lateral drainage is sometimes to two different ditches (field and regional).  This level of physical complexity steered the model design to a two-dimensional multi-layered approach.

The EAAMOD-FIELD model is a two-dimensional model that predicts flow and P losses from a field.  The hydraulic flow model divides the field into four vertical layers within the soil profile and numerous horizontal cells across the field.  These zones can vary in both hydraulic conductivity and aerobic state.  Any one of the cells can be a ditch and an impeding layer can be implemented.

The P model tracks the size of the mineral P pools (adsorbed and soluble/labile P).  Because the soil organic matter pool is dominant in size, it is the only organic matter pool considered, and it is assumed to be infinite.  Modeled P processes include mineralization and sorption-desorption while inputs of P can be from fertilizer, rainfall, and irrigation water.

Recently, a user-friendly Windows-based interface was developed for the EAAMOD-FIELD model.  The interface is designed to make the model useable by farmers, agricultural technical advisors, and governmental personnel.  It provides access to pre-defined EAA farming scenarios and the ability to manipulate the soils, phosphorus, and management parameters.  Farming scenarios include a number of soils, crops, water management options, and a large record of weather data.  Output is presented graphically or in tables and extensive on-line help is available.  Examples of some of the interface screens are given below.

EAAMOD modules/objects for the South Florida Water Management District’s (SFWMD’s) RSM model have been developed.  These modules will specifically handle the soil and cropping conditions found in the Everglades Agricultural Area south of Lake Okeechobee.  Two modules called EAAMod-Field and EAAMOD-Farm were developed and coded using the SFWMD’s Hydrologic Process Module (HPM) format to simulate the high water table / flatwood and histosol soil conditions for the SFWMD’s Regional Simulation Model’s (RSM) Hydrologic Simulation Engine (HSE).  The EAAMod-Field HPM was developed as a subclass to the PseudoCell class that defines the attributes and methods for simulating HPMs.

SWET in association with Breedlove, Dennis & Assoc. and Hazen and Sawyer performed a major update of the Lake Okeechobee Agricultural Decision Support System (LOADSS).   LOADSS is a GIS-based tool for evaluating the environmental and economic impacts of different agricultural management practices on reducing phosphorus loads from the Lake Okeechobee watershed.  LOADSS stores and retrieves data; edits modeling scenarios; and generates reports and maps.  Within LOADSS, a land use and phosphorus management plan can be developed using a menu-driven user interface.  LOADSS was originally developed with data collected from 1973 to 1987 and was updated by SWET to take into account the substantial changes in dairy land use and phosphorus management practices that occurred since 1987.  The updated LOADSS model also provides a better estimate of in-stream phosphorus assimilation.  In the previous version of LOADSS, the in-stream phosphorus assimilation was estimated using an exponential decay function based on flow travel distance.  However, the assimilation of phosphorus is influenced by many other factors.  In this study, an improved phosphorus assimilation algorithm was developed.  The algorithm is based on a second-order exponential relationship among flow rate, concentration, travel distance, and background concentration.  The updated LOADSS model was re-calibrated using observed tributary phosphorus loads from 1991 to 1995.  The updated model was used by Dr. Joyce Zhang with the SFWMD to evaluate alternative land use and phosphorus management strategies for reducing phosphorus loads to Lake Okeechobee.