Designing the NextGen Framework to Support Community Engagement

The Next Generation Water Resources Modeling Framework (NextGen) Framework is a standards based, model agnostic, model interoperability tool. The continued evolution of the National Water Model provided the impetus for its creation, but it was not created solely for that purpose. NextGen was intentionally designed to be a modular set of tools for both the National Weather Service, its Federal and academic partners, and the broader hydroscience community. This goal can be seen in both the designs of the framework design and the supporting tools. NextGen was designed to address simulations of varying complexity and spatial scales with simulations varying from a single catchment up to the continental scale. This flexibility means both a broad variety of scenarios can be modeled while keeping the hardware requirements for most modeling tasks modest.

The Framework design allows interoperability between the models being used. NextGen was designed so that it is not necessary to have to source code for models or to compile the models and framework together into a single application for every given task, provided that they comply with two widely accepted standards. These standards include the Community Surface Dynamics Modeling System, Basic Model Interface (BMI) model coupling standard, and the Open Geospatial Consortium, WaterML (version 2) Hydrographic Features (HY_Features) data model. Compliance with these standards allows the Framework to treat models in a fashion similarly to plugins in web browsers.. The tools for the hydrofabric, the underlying data supporting all models executed within the Framework, allows areas to be extracted from the continental domains. In a similar manner, a Forcings Engine was developed to provide atmospheric inputs from official forecasts. The Forcings Engine was designed to provide inputs for subregions and varying model discretizations. Our implementation of the BMI includes support for multiple programming languages, which expands our ability to interface with a wider range of domain science codes.

This presentation focuses on NextGen design decisions that promote community engagement.