Representing the Dupuit-Boussinesq Aquifer in the National Water Model: Catchment-Scale Application of Hydraulic Groundwater Theory

Abstract. The increasing importance of catchment-scale and basin-scale models of the hydrological cycle makes it desirable to have a simple, yet physically realistic model for lateral subsurface water flow. As a first building block towards such a model, analytical solutions are presented for horizontal groundwater flow to surface waters held at prescribed water levels for aquifers with parallel and radial flow. The solutions are valid for a wide array of initial and boundary conditions and additions or withdrawals of water, and can handle discharge into as well as lateral infiltration from the surface water. Expressions for the average hydraulic head, the flux to or from the surface water, and the aquifer-scale hydraulic conductivity are developed to provide output at the scale of the modelled system rather than just point-scale values. The upscaled conductivity is time-variant. It does not depend on the magnitude of the flux but is determined by medium properties as well as the external forcings that drive the flow. For the systems studied, with lateral travel distances not exceeding 10 m, the circular aquifers respond very differently from the infinite-strip aquifers. The modelled fluxes are sensitive to the magnitude of the storage coefficient. For phreatic aquifers a value of 0.2 is argued to be representative, but considerable variations are likely. The effect of varying distributions over the day of recharge damps out rapidly; a soil water model that can provide accurate daily totals is preferable over a less accurate model hat correctly estimates the timing of recharge peaks.

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Impact of Real‐Time Satellite‐Derived Green Vegetation Fraction on National Water Model Fluxes in Humid Alabama Watersheds

JAWRA Journal of the American Water Resources Association ◽

10.1111/1752-1688.12982 ◽

2022 ◽

Author(s):

Nicholas J. Elmer ◽

John R. Mecikalski ◽

Andrew L. Molthan ◽

David J. Gochis ◽

Udaysankar Nair

Keyword(s):

Real Time ◽

Water Model ◽

Vegetation Fraction ◽

Green Vegetation ◽

National Water

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General Assessment of the Operational Utility of National Water Model Reservoir Inflows for the Bureau of Reclamation Facilities

Water ◽

10.3390/w12102897 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2897

Author(s):

Francesca Viterbo ◽

Laura Read ◽

Kenneth Nowak ◽

Andrew W. Wood ◽

David Gochis ◽

...

Keyword(s):

Water Model ◽

Short Term ◽

Bureau Of Reclamation ◽

Hydrologic Processes ◽

One Year ◽

Inflow Performance ◽

Basin Area ◽

National Water ◽

Total Inflow

This work investigates the utility of the National Oceanic and Atmospheric Administration’s National Water Model (NWM) for water management operations by assessing the total inflow into a select number of reservoirs across the Central and Western U.S. Total inflow is generally an unmeasured quantity, though critically important for anticipating both floods and shortages in supply over a short-term (hourly) to sub-seasonal (monthly) time horizon. The NWM offers such information at over 5000 reservoirs across the U.S., however, its skill at representing inflow processes is largely unknown. The goal of this work is to understand the drivers for both well performing and poor performing NWM inflows such that managers can get a sense of the capability of NWM to capture natural hydrologic processes and in some cases, the effects of upstream management. We analyzed the inflows for a subset of Bureau of Reclamation (BoR) reservoirs within the NWM over the long-term simulations (retrospectively, seven years) and for short, medium and long-range operational forecast cycles over a one-year period. We utilize ancillary reservoir characteristics (e.g., physical and operational) to explain variation in inflow performance across the selected reservoirs. In general, we find that NWM inflows in snow-driven basins outperform those in rain-driven, and that assimilated basin area, upstream management, and calibrated basin area all influence the NWM’s ability to reproduce daily reservoir inflows. The final outcome of this work proposes a framework for how the NWM reservoir inflows can be useful for reservoir management, linking reservoir purposes with the forecast cycles and retrospective simulations.

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Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment

Hydrology and Earth System Sciences ◽

10.5194/hess-6-67-2002 ◽

2002 ◽

Vol 6 (1) ◽

pp. 67-84 ◽

Cited By ~ 24

Author(s):

S. P. Anderton ◽

J. Latron ◽

S. M. White ◽

P. Llorens ◽

F. Gallart ◽

...

Keyword(s):

Model Performance ◽

Flow Simulation ◽

Water Model ◽

Distributed Model ◽

Canopy Interception ◽

Catchment Scale ◽

Phreatic Surface ◽

Internal Evaluation ◽

Mountain Catchment ◽

Physically Based

Abstract. An evaluation of the performance of a physically-based distributed model of a small Mediterranean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreatic surface level and actual evapotranspiration. A-priori model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judged in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated against a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water model was preventing adequate representation of drainage from soils during hydrograph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid. Keywords: physically-based distributed model, SHETRAN, parameterisation, Mediterranean mountain catchment, internal evaluation, multi-response

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Modeling Streamflow Enhanced by Precipitation from Atmospheric River Using the NOAA National Water Model: A Case Study of the Russian River Basin for February 2004

Atmosphere ◽

10.3390/atmos10080466 ◽

2019 ◽

Vol 10 (8) ◽

pp. 466 ◽

Cited By ~ 4

Author(s):

Heechan Han ◽

Jungho Kim ◽

V. Chandrasekar ◽

Jeongho Choi ◽

Sanghun Lim

Keyword(s):

Water Content ◽

Soil Water ◽

Soil Water Content ◽

River Basin ◽

Hydrologic Model ◽

Hydrological Processes ◽

Water Model ◽

Atmospheric River ◽

Russian River ◽

National Water

This study aims to address hydrological processes and impacts of an atmospheric river (AR) event that occurred during 15–18 February 2004 in the Russian River basin in California. The National Water Model (NWM), a fully distributed hydrologic model, was used to evaluate the hydrological processes including soil moisture flux, overland flow, and streamflow. Observed streamflow and volumetric soil water content data were used to evaluate the performance of the NWM using various error metrics. The simulation results showed that this AR event (15–18 February 2004) with a long duration of precipitation could cause not only deep soil saturation, but also high direct runoff depth. Taken together, the analysis revealed the complex interaction between precipitation and land surface response to the AR event. The results emphasize the significance of a change of water contents in various soil layers and suggest that soil water content monitoring could aid in improving flood forecasting accuracy caused by the extreme events such as the AR.

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Featured Collection Introduction: National Water Model

JAWRA Journal of the American Water Resources Association ◽

10.1111/1752-1688.12664 ◽

2018 ◽

Vol 54 (4) ◽

pp. 767-769 ◽

Cited By ~ 12

Author(s):

Sagy Cohen ◽

Sarah Praskievicz ◽

David R. Maidment

Keyword(s):

Water Model ◽

National Water

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A Comparison of National Water Model Retrospective Analysis Snow Outputs at SNOTEL Sites Across the Western U.S.

10.22541/au.161656955.51617798/v1 ◽

2021 ◽

Author(s):

Irene Garousi-Nejad ◽

David Tarboton

Keyword(s):

Snow Water Equivalent ◽

Water Model ◽

Central Basin ◽

Model Errors ◽

Considerable Variability ◽

Snow Covered Area ◽

Covered Area ◽

Snow Water ◽

The U.S ◽

National Water

This study compares the U.S. National Water Model (NWM) reanalysis snow outputs to observed snow water equivalent (SWE) and snow-covered area fraction (SCAF) at SNOTEL sites across the Western U.S. This was done to evaluate and identify opportunities for improving the modeling of snow in the NWM. SWE was obtained from SNOTEL sites, while SCAF was obtained from MODIS observations at a nominal 500 m grid scale. Retrospective NWM results were at a 1000 m grid scale. We compared results for SNOTEL sites to gridded NWM and MODIS outputs for the grid cells encompassing each SNOTEL site. Differences between modeled and observed SWE were attributed to both model errors, as well as errors in inputs, notably precipitation and temperature. The NWM generally under-predicted SWE, partly due to precipitation input differences. There was also a slight general bias for model input temperature to be cooler than observed, counter to the direction expected to lead to under-modeling of SWE. There was also under-modeling of SWE for a subset of sites where precipitation inputs were good. Furthermore, the NWM generally tends to melt snow early. There was considerable variability between modeled and observed SCAF that hampered useful interpretation of these comparisons. This is in part due to the model grid SCAF essentially being binary (snow or no snow) while observations from MODIS are much more fractional. However, when SCAF was aggregated across all sites and years, modeled SCAF tended to be more than observed using MODIS. These differences are regional with generally better SWE and SCAF results in the Central Basin and Range and differences tending to become larger the further away regions are from this region. These findings identify areas where predictions from the NWM involving snow may be better or worse, and suggest opportunities for research directed towards model improvements.

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A Comparison of National Water Model Retrospective Analysis Snow Outputs at SNOTEL Sites Across the Western U.S.

Hydrological Processes ◽

10.1002/hyp.14469 ◽

2022 ◽

Author(s):

Irene Garousi‐Nejad ◽

David G. Tarboton

Keyword(s):

Retrospective Analysis ◽

Water Model ◽

National Water

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A Multiscale, Hydrometeorological Forecast Evaluation of National Water Model Forecasts of the May 2018 Ellicott City, Maryland, Flood

Journal of Hydrometeorology ◽

10.1175/jhm-d-19-0125.1 ◽

2020 ◽

Vol 21 (3) ◽

pp. 475-499 ◽

Cited By ~ 6

Author(s):

Francesca Viterbo ◽

Kelly Mahoney ◽

Laura Read ◽

Fernando Salas ◽

Bradford Bates ◽

...

Keyword(s):

Flash Flood ◽

Model Development ◽

Extreme Rainfall ◽

Precipitation Forecast ◽

Water Model ◽

Extreme Rainfall Event ◽

Flood Prediction ◽

Streamflow Forecasts ◽

Atmospheric Forcings ◽

National Water

AbstractThe NOAA National Water Model (NWM) became operational in August 2016, producing the first ever real-time, distributed, continuous set of hydrologic forecasts over the continental United States (CONUS). This project uses integrated hydrometeorological assessment methods to investigate the utility of the NWM to predict catastrophic flooding associated with an extreme rainfall event that occurred in Ellicott City, Maryland, on 27–28 May 2018. Short-range forecasts (0–18-h lead time) from the NWM version 1.2 are explored, focusing on the quantitative precipitation forecast (QPF) forcing from the High-Resolution Rapid Refresh (HRRR) model and the corresponding NWM streamflow forecast. A comprehensive assessment of multiscale hydrometeorological processes are considered using a combination of object-based, grid-based, and hydrologic point-based verification. Results highlight the benefits and risks of using a distributed hydrologic modeling tool such as the NWM to connect operational CONUS-scale atmospheric forcings to local impact predictions. For the Ellicott City event, reasonably skillful QPF in several HRRR model forecast cycles produced NWM streamflow forecasts in the small Ellicott City basin that were suggestive of flash flood potential. In larger surrounding basins, the NWM streamflow response was more complex, and errors were found to be governed by both hydrologic process representation, as well as forcing errors. The integrated, hydrometeorological multiscale analysis method demonstrated here guides both research and ongoing model development efforts, along with providing user education and engagement to ultimately engender improved flash flood prediction.

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