Client-side Web-based Model Coupling Using Basic Model Interface for Hydrology and Water Resources

A recent trend in hydroinformatics has been the growing number of data, models, and cyber tools which are web accessible, each aiming to improve common research tasks in hydrology through web technologies. Coupling web-based models and tools holds great promise for an integrated environment that can facilitate community participation, collaboration, and scientific replication. There are many examples of server-side, hydroinformatics resource coupling, where a common standard serves as an interface. Yet, there are few, if any, examples of client-side, resource coupling, particularly cases where a common specification is employed. Towards this end, we implemented the Basic Model Interface (BMI) specification in the JavaScript programming language, the most widely used programming language on the web. Using the BMI, we coupled two comprehensive, client-side hydrological applications (HydroLang and HLM-Web) to perform rainfall-runoff simulations of historical events as a case study demonstration. Through this process, we present how a common and often tedious task – the coupling of two independent web-resources – can be made easier through the adoption of a common standard. Furthermore, applying the standard has facilitated a step towards the possibility of client-side model as a service for hydrological models.