Full Coupling Between the Atmosphere, Surface, and Subsurface for Integrated Hydrologic Simulation

Abstract

An ever increasing community of earth system modelers is incorporating new physical processes into numerical models. This trend is facilitated by advancements in computational resources, improvements in simulation skill, and the desire to build numerical simulators that represent the water cycle with greater fidelity. In this quest to develop a state‐of‐the‐art water cycle model, we coupled HydroGeoSphere (HGS), a 3‐D control‐volume finite element surface and variably saturated subsurface flow model that includes evapotranspiration processes, to the Weather Research and Forecasting (WRF) Model, a 3‐D finite difference nonhydrostatic mesoscale atmospheric model. The two‐way coupled model, referred to as HGS‐WRF, exchanges the actual evapotranspiration fluxes and soil saturations calculated by HGS to WRF; conversely, the potential evapotranspiration and precipitation fluxes from WRF are passed to HGS. The flexible HGS‐WRF coupling method allows for unique meshes used by each model, while maintaining mass and energy conservation between the domains. Furthermore, the HGS‐WRF coupling implements a subtime stepping algorithm to minimize computational expense. As a demonstration of HGS‐WRF's capabilities, we applied it to the California Basin and found a strong connection between the depth to the groundwater table and the latent heat fluxes across the land surface.

Untangling global change impacts on hydrological processes: Resisting climatization

“…Thus, appropriately accounting for these interactions is central to properly understanding global change impacts. Noting the importance of accounting for impacts of groundwater pumping when predicting climate change effects, physically based coupled surface–subsurface hydrologic modelling has advanced rapidly from conceptual proof of concept (Davison, Hwang, Sudicky, & Lin, ; Jones, Sudicky, Brookfield, & Park, ; Maxwell et al, ; Sudicky, Jones, Park, Brookfield, & Colautti, ) to basin‐scale simulations (Davison, Hwang, Sudicky, Mallia, & Lin, ; Erler et al, ; Ferguson & Maxwell, ; Hwang et al, ; Maxwell & Condon, ). Variable local weather systems alter hydrological processes, and human water use exaggerates this feedback.…”

Intra-catchment variability of surface saturation – insights from longterm observations and simulations

“…HGS has been used in the past for addressing diverse questions at various temporal and spatial scales (e.g. Ala-aho et al, 2015;Davison et al, 2018;Erler et al, 2019;Frei et al, 2010;Munz et al, 2017;Nasta et al, 2019;Partington et al, 2013;Schilling et al, 2017;Tang et al, 2018). It also has already been applied for a 6 ha headwater region of the Weierbach catchment (Glaser et al, 2016.…”

A Comprehensive Review of Low Impact Development Models for Research, Conceptual, Preliminary and Detailed Design Applications

“…PCSWMM, MIKE Urban and Win-SLAMM consider a maximum of two layers for bioretention cells, while HEC-HMS is limited to one layer for the catchment. The hydrological models typically model the system as a one-dimensional system (with a focus on surface flow), but adding multiple soil layers requires the addition of a second dimension to model the subsurface flow [85]. Modelling subsurface flow has the additional complexity of integrating the flow interactions between the surface and subsurface flow, both in the vadose and saturated zones.…”