Accelerating advances in continental domain hydrologic modeling

Abstract

In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

Understanding hydrologic variability across Europe through catchment classification

“…This knowledge could be valuable when estimating parameter values for continental-scale hydrological models. Currently, there is an emerging need for parameter estimation also in ungauged basins from several modeling communities (Archfield et al, 2015). For instance, traditional catchment models have recently been applied on a pan-European scale, e.g., SWAT (Abbaspour et al, 2015) and HYPE .…”

Toward continental hydrologic–hydrodynamic modeling in South America

“…estimates (Sood and Smathkin, 2015), their ability to reproduce discharge observations at basin scale and to address practical water management issues is still limited (Archfield et al, 2015;Hattermann et al, 2018). Inaccuracies in runoff estimation from GHMs and LSMs may be first attributed to the uncertainty in global satellite precipitation products (Tian and PetersLidard, 2010;Sperna Weiland et al, 2015), but several studies have shown considerable differences between model outputs even when using the same meteorological forcing, given the lack of knowledge about runoff generation processes and 30 deficiencies in parameter estimation (e.g., Haddeland et al, 2011;Gudmundsson et al, 2012;Zhou et al, 2012;Beck et al, 2017a).…”

Parameter regionalization of a monthly water balance model for the conterminous United States

“…This may be due to inadequate forcing data, the quality of which "is paramount in hydrologic modeling efforts" (Archfield et al, 2015) and/or the lack of good reference streamflow data for calibration and evaluation. Both surely play a role and emphasize the need for incorporation of additional data sets so that calibration and evaluation of intermediate states in the hydrologic cycle are examined.…”

“…Archfield et al (2015) state that the performance of continental-domain hydrologic models is considerably constrained by inadequate model representation of dominant hydrologic processes. For example, the simplicity of the MWBM presents limitations on the representation of deeper groundwater reservoirs, gain-ing and losing stream reaches, simplistic AET, and the effects of surface processes (infiltration and overland flow) that need to be represented at finer time steps than monthly.…”