A generic approach for developing process-level hydrologic modeling components

Component software architectures offer an alternative approach for building large, 4 complex hydrologic modeling systems. In contrast to more traditional software 5 paradigms (i.e. procedural or object-oriented approaches), using component-based 6 approaches allows individuals to construct autonomous modeling units that can be linked 7 together through shared boundary conditions during a simulation run. One of the 8 challenges in component-based modeling is designing a simple yet robust means for 9 authoring model components. We address this challenge by presenting an approach for 10 efficiently creating standards-based, process-level hydrologic modeling components. 11 Using this approach, a hydrologic process is implemented as a modeling component by 12 (1) authoring a configuration file that defines the properties of the component and (2) 13 creating a class with three methods that define the pre-run, runtime, and post-run 14 behavior of the modeling component. We present the design and implementation of this 15 approach, which we call the Simple Model Wrapper (SMW), and demonstrate how it can 16 be applied to create an Open Modeling Interface (OpenMI)-compliant modeling 17 component for a basic hydrologic process. 18 Subject Headings: Hydrologic modeling; Modeling software architectures; 19 Component-based modeling; Integrated Modeling; Multi-disciplinary modeling 20