A process-based diagnostic approach to model evaluation: Application to the NWS distributed hydrologic model

Yılmaz, Koray Kamil
Wagener, Thorsten
Distributed hydrological models have the potential to provide improved streamflow forecasts along the entire channel network, while also simulating the spatial dynamics of evapotranspiration, soil moisture content, water quality, soil erosion, and land use change impacts. However, they are perceived as being difficult to parameterize and evaluate, thus translating into significant predictive uncertainty in the model results. Although a priori parameter estimates derived from observable watershed characteristics can help to minimize obstacles to model implementation, there exists a need for powerful automated parameter estimation strategies that incorporate diagnostic information regarding the causes of poor model performance. This paper investigates a diagnostic approach to model evaluation that exploits hydrological context and theory to aid in the detection and resolution of watershed model inadequacies, through consideration of three of the four major behavioral functions of any watershed system; overall water balance, vertical redistribution, and temporal redistribution (spatial redistribution was not addressed). Instead of using classical statistical measures (such as mean squared error), we use multiple hydrologically relevant "signature measures'' to quantify the performance of the model at the watershed outlet in ways that correspond to the functions mentioned above and therefore help to guide model improvements in a meaningful way. We apply the approach to the Hydrology Laboratory Distributed Hydrologic Model (HL-DHM) of the National Weather Service and show that diagnostic evaluation has the potential to provide a powerful and intuitive basis for deriving consistent estimates of the parameters of watershed models.


The Auto-Tuned Land Data Assimilation System ( ATLAS)
Crow, W. T.; Yılmaz, Mustafa Tuğrul (American Geophysical Union (AGU), 2014-01-01)
Land data assimilation systems are commonly tasked with merging remotely sensed surface soil moisture retrievals with information derived from a soil water balance model driven by observed rainfall. The performance of such systems can be degraded by the incorrect specification of parameters describing modeling and observation errors. Here the Auto-Tuned Land Data Assimilation System (ATLAS) is introduced to simultaneously solve for all parameters required for the application of a simple land data assimilati...
Toward predicting climate change effects on lakes: a comparison of 1656 shallow lakes from Florida and Denmark reveals substantial differences in nutrient dynamics, metabolism, trophic structure, and top-down control
Jeppesen, Erik; Canfield, Daniel E.; Bachmann, Roger W.; Sondergaard, Martin; Havens, Karl E.; Johansson, Liselotte S.; Lauridsen, Torben L.; Tserenpil, Sh; Rutter, Robert P.; Warren, Gary; Ji, Gaohua; Hoyer, Mark (Informa UK Limited, 2020-04-01)
Rapid climate changes may potentially have strong impacts on the ecosystem structure and nutrient dynamics of lakes as well as implications for water quality. We used a space-for-time approach to elucidate such possible effects by comparing data from 1656 shallow lakes (mean depth 100 mu g L-1) in the FL lakes, but coverage was higher in the DK lakes at low TP. We also found lower oxygen saturation in the nutrient-rich FL lakes than in the DK lakes, suggesting lower net ecosystem production in the FL lakes....
Point-scale energy and mass balance snowpack simulations in the upper Karasu basin, Turkey
Sensoy, A; Sorman, AA; Tekeli, AE; Sorman, AU; Garen, DC (Wiley, 2006-03-15)
Since snowmelt runoff is important in the mountainous parts of the world, substantial efforts have been made to develop snowmelt models with many different levels of complexity to simulate the processes at the ground (soil-vegetation), within the snow, and at the interface with the atmosphere. Snow modifies the exchange of energy between the land surface and atmosphere and significantly affects the distribution of heating in the atmosphere by changing the surface albedo and regulating turbulent heat and mom...
Multiple-criteria calibration of a distributed watershed model using spatial regularization and response signatures
Pokhrel, Prafulla; Yılmaz, Koray Kamil; Gupta, Hoshin V. (Elsevier BV, 2012-02-08)
This paper explores the use of a semi-automated multiple-criteria calibration approach for estimating the parameters of the spatially distributed HL-DHM model to the Blue River basin, Oklahoma. The study was performed in the context of Phase 2 of the DMIP project organized by the Hydrology Lab of the NWS. To deal with the problem of ill conditioning, we employ a regularization approach that constrains the search space using information contained in a priori estimates of the spatially distributed parameter f...
A double-porosity model for a fractured aquifer with non-Darcian flow in fractures
Altinors, Altay; Onder, Halil (Informa UK Limited, 2008-08-01)
Non-Darcian flow in a finite fractured confined aquifer is Studied. A stream bounds the aquifer at one side and all impervious Stratum at the other. The aquifer consists of fractures capable of transmitting water rapidly, and Porous blocks which mainly store water. Unsteady flow in the aquifer due to a Sudden rise in the stream level is analysed by the double-porosity conceptual model. Governing equations for the flow in fractures and blocks are developed using the continuity equation. The fluid velocity in...
Citation Formats
K. K. Yılmaz and T. Wagener, “A process-based diagnostic approach to model evaluation: Application to the NWS distributed hydrologic model,” WATER RESOURCES RESEARCH, pp. 0–0, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47150.