Investigating Hydrological Processes Controlling Streamflow Generation at the Panola Mountain Research Watershed, Georgia
Abstract
Runoff simulations of the Panola Mountain Research Watershed (PMRW) using Dynamic TOPMODEL improved compared to those of the original version of TOPMODEL. These improvements, in part, were due to the ability to define structurally different landscape units that better represent the spatial hydrological characteristics of the PMRW catchment. The model also allows for a dynamically variable saturated zone. However, model simulations were still deficient, especially with respect to capturing seasonality. An analysis of seasonal responses (dry, wetting, wet and drying periods) during 3 years resulted in the rejection of all model simulations within the Generalized Likelihood Uncertainty Estimation (GLUE procedure), a Monte Carlo based simulation methodology. The rejection of the simulations resulted from non-overlapping behavioral parameter distributions for the different seasonal periods, i.e. the parameter sets for the best models differed seasonally. The spatial characterization of the three landscape units (bedrock outcrop, hillslope and riparian zone/valley bottom) were re-evaluated in more detail with respect to hydrological and hydrochemical responses (e.g., subcatchment discharge and water quality, ground-water level and quality, hillslope discharge and water quality, TDR soil moisture) at different spatial scales over a 19-year period from 1985 to 2004 to gain a better representation of the connectivity and linkages among landscape units. The analyses of hydrometric data are used to restructure the hydrologic model of PMRW, with the aim of improving the model's spatial representation. The paper will discuss the data analyses, the reformulation of the model, and present the results from new simulations within the GLUE procedure. The important questions are: (1) does the new model predict runoff better than the previous models; (2) how do we know that the new model has a more realistic physically based structure; and (3) are temporal and spatial water-quality variations consistent with the hydrological model results?
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.H44B..02P
- Keywords:
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- 1831 Groundwater quality;
- 1854 Precipitation (3354);
- 1860 Runoff and streamflow;
- 1866 Soil moisture;
- 1871 Surface water quality