The UP modelling system for large scale hydrology: simulation of the Arkansas-Red River basin

Abstract. The UP (Upscaled Physically-based) hydrological modelling system to the Arkansas-Red River basin (USA) is designed for macro-scale simulations of land surface processes, and aims for a physical basis and, avoids the use of discharge records in the direct calibration of parameters. This is achieved in a two stage process: in the first stage parametrizations are derived from detailed modelling of selected representative small and then used in a second stage in which a simple distributed model is used to simulate the dynamic behaviour of the whole basin. The first stage of the process is described in a companion paper (Ewen et al., this issue), and the second stage of this process is described here. The model operated at an hourly time-step on 17-km grid squares for a two year simulation period, and represents all the important hydrological processes including regional aquifer recharge, groundwater discharge, infiltration- and saturation-excess runoff, evapotranspiration, snowmelt, overland and channel flow. Outputs from the model are discussed, and include river discharge at gauging stations and space-time fields of evaporation and soil moisture. Whilst the model efficiency assessed by comparison of simulated and observed discharge records is not as good as could be achieved with a model calibrated against discharge, there are considerable advantages in retaining a physical basis in applications to ungauged river basins and assessments of impacts of land use or climate change.

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UP Modelling System for large scale hydrology: deriving large-scale physically-based parameters for the Arkansas-Red River basin

Hydrology and Earth System Sciences ◽

10.5194/hess-3-125-1999 ◽

1999 ◽

Vol 3 (1) ◽

pp. 125-136 ◽

Cited By ~ 6

Author(s):

J. Ewen ◽

W. T. Sloan ◽

C. G. Kilsby ◽

P. E. O'Connell

Keyword(s):

River Basin ◽

Large Scale ◽

Red River ◽

Environmental Research ◽

Fine Scale ◽

Red River Basin ◽

Physically Based ◽

Up Elements ◽

The Impact ◽

Modelling System

Abstract. The UP modelling system has been applied to the 570,000 km2 Arkansas-Red River Basin (ARRB) as part of the UK NERC Terrestrial initiative in Global Environmental Research (TIGER). The model can be run as a stand-alone basin hydrology model or be linked to existing climate and weather forecasting models. It runs on a grid comprising 1923 UP elements, each 17km by 17km in area, and each containing five water storage compartments: one each for the snowpack, vegetation canopy, surface water, root zone and groundwater. All the main transfers and processes of the terrestrial phase of the hydrological cycle are represented, including river network routing of the runoff from the UP elements. The parameters of the ARRB model are physically-based, being derived either from fine-scale, sub-grid, data on the topography and physical properties of the soils, aquifers and vegetation of the basin, or from the results of fine-scale physically-based simulations. With the approach, the parameters account for the effects of sub-grid variations in moisture status and spatial distribution and are sensitive to changes in the fine-scale property data. This sensitivity is either absent or less directly represented in existing large-scale hydrology models, yet it plays a central role in studies of the impact of changes in climate and land-use. The ARRB model, as described here and in Kilsby et al. (1999), is a first attempt at large-scale physically-based hydrological modelling of the type outlined in the "blueprint" for the UP system (Ewen, 1997), and gives a clear, positive, indication of the nature and quality of what is currently practical with the approach.

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Multidecadal High-Resolution Hydrologic Modeling of the Arkansas–Red River Basin

Journal of Hydrometeorology ◽

10.1175/jhm622.1 ◽

2007 ◽

Vol 8 (5) ◽

pp. 1111-1127 ◽

Cited By ~ 12

Author(s):

Hatim O. Sharif ◽

W. Crow ◽

N. L. Miller ◽

E. F. Wood

Keyword(s):

High Resolution ◽

River Basin ◽

Empirical Model ◽

Land Surface ◽

The United States ◽

Precipitation Variability ◽

Red River ◽

Surface Model ◽

Red River Basin ◽

Good Agreement

Abstract Land surface heterogeneity and its effects on surface processes have been a concern to hydrologists and climate scientists for the past several decades. The contrast between the fine spatial scales at which heterogeneity is significant (1 km and finer) and the coarser scales at which most climate simulations with land surface models are generated (hundreds of kilometers) remains a challenge, especially when incorporating land surface and subsurface lateral fluxes of mass. In this study, long-term observational land surface forcings and derived solar radiation were used to force high-resolution land surface model simulations over the Arkansas–Red River basin in the Southern Great Plains region of the United States. The most unique aspect of these simulations is the fine space (1 km2) and time (hourly) resolutions within the model relative to the total simulation period (51 yr) and domain size (575 000 km2). Runoff simulations were validated at the subbasin scale (600–10 000 km2) and were found to be in good agreement with observed discharge from several unregulated subbasins within the system. A hydroclimatological approach was used to assess simulated annual evapotranspiration for all subbasins. Simulated evapotranspiration values at the subbasin scale agree well with predictions from a simple one-parameter empirical model developed in this study according to Budyko’s concept of “geographical zonality.” The empirical model was further extended to predict runoff and evapotranspiration sensitivity to precipitation variability, and good agreement with computed statistics was also found. Both the empirical model and simulation results demonstrate that precipitation variability was amplified in the simulated runoff. The finescale at which the study is performed allows analysis of various aspects of the hydrologic cycle in the system including general trends in precipitation, runoff, and evapotranspiration, their spatial distribution, and the relationship between precipitation anomalies and runoff and soil water storage anomalies at the subbasin scale.

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