Recent decades have seen a proliferation of hydrologic models designed for different purposes and representing different processes at different spatial-temporal scales. The time has arrived for our community to take a collective look at our rich, diverse but disorganized modeling landscape, to synthesize what we know and don’t know, and to agree upon a framework for developing, testing and maintaining a suite of community-level models or model components
CUAHSI directly supports two major modeling initiatives. The National Water Center Summer Institute helps to advance NOAA's National Water Model while the HydroCLM effort seeks to create systematic ways to translate discoveries from the field and laboratory into theories and models that are accessible to the broader earth science community for identifying ways to represent the water cycle at all scales of research.
The National Water Model (NWM) is a hydrologic model developed by NOAA that simulates observed and forecast streamflow over the continental United States. CUAHSI supports the enhancement and applications of the NWM through the Summer Institute.
Initial discussions with the Community Land Model (CLM) working group at NCAR was initiated before and at the CUAHSI fourth Biennial Science Meeting in July 2014 and a follow up workshop was held at NCAR in September 2014. The discussions led to the suggestion that a Hydrology Process Team (HPT) be formed to conduct a synthesis of process-understanding, to incorporate state-of-science schemes into the next generation CLM, and to develop meaningful ways to benchmark model performance. The workshop report can be viewed here.
A second workshop was held at AGU in December 2014 focusing on developing a framework for multivariate and multi-scale hydrologic benchmarking using the rich set of observations at CZOs and research watersheds as well as from satellite remote sensing, supported by the CUAHSI Water Data Center. The workshop report can be viewed here.
A WRR paper on the scientific drivers behind the effort and the opportunities and key challenges to improve hydrologic process representations and benchmarking in earth system models can be viewed here. To obtain funding for this effort, a collaborative INSPIRE proposal between CUAHSI and NCAR was submitted in January 2015, and it is jointly funded by three NSF programs: Hydrologic Sciences, Physical and Dynamic Meteorology, and Climate and Large-Scale Dynamics. We propose to form a Hydrology Process Team (HPT) with the following focused tasks: (1) A first synthesis workshop at NCAR with ~30 leading scientists from the hydrology and atmospheric science communities; the objective is to develop state-of-science synthesis of hydrologic processes and recommend best ways to represent them in large-scale models; (2) Implement synthesis recommendations in the Community Land Model (CLM), supporting a postdoc and a software engineer to complete the coding; (3) Test/benchmark progress in CLM water cycle simulations with observations, bringing in the rich set of hydrologic observations yet to be tapped for testing large-scale water cycle models, e.g., from the NSF-funded Critical Zone Observatories (CZOs), and the research watersheds of USDA, USGS and USFS; (4) Conduct CLM/CESM simulations to demonstrate new model capabilities in addressing long-standing science questions; and (5) A final synthesis workshop; based on the results of benchmarking and demonstration of new science capabilities (or lack of), the synthesis team will analyze model deficiencies and recommend future model development and observation priorities. The Project Summary can be viewed here.