Using the Parallel WASH123D Code to Simulate Overland-Subsurface Interactions

WASH123D model is a first-principle, physics-based model, where water flow and/or contaminant and sediment transport within a watershed system are computed. In the WASH123D model, a watershed is conceptualized as a coupled system of 1-D canal /stream network, 2-D overland regime, and 3-D subsurface media. It is designed to answer the environmental issues concerning both water quantity and quality. To reach numerical solutions with reasonable and tolerable computer time for a regional scale watershed simulation, numerical algorithm improvement and code parallelization are two essential tasks when a distributed numerical model, WASH123D, is used. This paper presents the code parallelization approach, followe d by demonstrating its scalability performance. The test problem of a large mesh uses the topographic data in the C -111 Spreader Canal Project. Background The C-111 Spreader Canal Project is one component of the more than 60 restoration plans under the Comprehensive Environmental Restoration Plan (CERP) and has a goal to provide water deliveries that will enhance the connection between the natural areas in the Southern Glades and Model Lands area of South Dade County. The spreader canal