MODSIM: Decision Support System for Integrated River Basin Management

MODSIM 8.0 is a generic river basin management decision support system for analysis of long term planning, medium term management, and short term operations on desktop computers operating under MS Windows 2000/XP. MODSIM is free from expensive licenses for proprietary software since all components are developed from native code or shareware under the MS .NET Framework. MODSIM includes a powerful, interactive graphical user interface for creating, locating and connecting river basin network components, as well as spreadsheet-style data editing in an object-oriented spatial data base management system. Flexible data import and export tools are included for interaction with external data base management systems. One of the greatest advantages of the MS .NET Framework is the ability to customize MODSIM for any specialized operating rules, input data, output reports, and access to external modules such as water quality models running concurrently with MODSIM, all without having to modify the original source code. The basic solver in MODSIM is a state-of-the-art network flow optimization algorithm up to two orders of magnitude faster than solvers in other river basin modeling packages and capable of simulating complex, large-scale networks. An iterative solution procedure allows consideration of non-network and conditional constraints. GEO-MODSIM, a full implementation of MODSIM operating as a custom extension in ArcGIS (ESRI, Inc.), allows automatic generation of MODSIM networks from geometric networks and processing of spatial database information in a GIS.