Hydrologic response of freshwater watersheds to climatic variability: Model development

Abstract

To evaluate the hydrologic and biogeochemical response of freshwater watersheds to climatic variability properly, a mathematical model with detailed parameterization in describing the hydrologic and thermal processes in a watershed is needed. For this purpose, the Enhanced Trickle Down model was modified to predict the hydrologic and thermal responses of freshwater watersheds to various climate change scenarios. Modifications of the model included the incorporation of an energy transfer submodel, an improved hydraulic conductivity scheme, and the coupling with a point source snowmelt model. The results of calibration and verification of the model using 8 years of field data collected at the Agricultural Research Service, W-3 watershed, located near Danville, Vermont, are presented. Forecast System. Their results indicated a seasonal shift in the snow accumulation pattern, increased winter runoff, and increased flood maxima under atmospheric carbon dioxide doubling scenarios. The Thornthwaite moisture index (an indicator of precipitation relative to evapotranspiration) was used to examine the effects of climatic changes on water resources in United States by McCabe et al. [1990]. The above studies, although very useful, provide a first cut estimate of the effect that climatic changes would have on freshwater watersheds. The uncertainty introduced in the estimates is due to the structure of the above mentioned models that incorporate simplified parameterizations of the hydrologic cycles. This paper presents the development of a model for the evaluation of the hydrologic and climate feedback responses of watershed ecosystems, using a detailed parameterization to describe the hydrologic and thermal processes of the terrestrial and aquatic portions of freshwater watersheds. The model presented in this paper is based on the Enhanced Trickle Down (ETD) model [Nikolaidis et al., 1988, 1989], which was modified to include an energy budget submodel and improved parameterization of the evapotranspiration, snow hydrology, and hydraulic conductivity components of the model. The model was calibrated and verified using field data from the W-3 watershed near Danville, Vermont. A conventional sensitivity analysis was also performed on the model parameters to determine which processes are most important. The aim of this research is to develop a tool that would reduce the uncertainties in evaluating the effects of global climate change on freshwater watersheds. This modified version of the ETD model represents an advance over the simple precipitation/soil moisture relationship studies presented earlier, and it is expected to provide better insight into the study of the effects of climatic change on watersheds. MODEL DEVELOPMENT The Enhanced Trickle Down (ETD) model is a mathemat-

Surface‐subsurface flow modeling with path‐based runoff routing, boundary condition‐based coupling, and assimilation of multisource observation data

“…Water‐driven interactions between the atmosphere, the land surface (including water bodies), and the subsurface are increasingly relevant in water management, ecology, and climate studies [e.g., Winter et al , 1998; Woessner , 2000; Sankarasubramanian et al , 2001]. Surface‐subsurface interactions have been investigated over a range of scales, from hillslope and streambed [e.g., Harvey and Bencala , 1993; Fan and Bras , 1998; Storey et al , 2003] to river and watershed [e.g., Nikolaidis et al , 1993; Michaud and Sorooshian , 1994; Blasch et al , 2006]. Nevertheless, there are important unresolved issues in hydrology concerning the differences in response between hillslopes, catchments, and river networks.…”

MODELING OF NONPOINT SOURCE POLLUTION OF NITROGEN AT THE WATERSHED SCALE1

“…Soil temperatures are calculated using the force-restore method. A detailed description of the energy budget can be found in Nikolaidis et al (1993a). Overland flow occurs as a result of rainfall in excess of the soil surface infiltration capacity and the storage capacity of the depressions.…”

Hydrological implications of land use and land cover change: Spatial analytical approach at regional scale in the closed basin of the Cuitzeo Lake, Michoacan, Mexico

“…The usefulness of hydrological modelling, either in small basins or at the regional level, has been broadly demonstrated in the evaluation of the impacts of both land use and land cover change (LULCC) (Henderson‐Sellers et al ., 1993; Kite, 1993; Harbor,1994; Bhaduri et al ., 1997; Sharma et al ., 2000; Bronstert et al ., 2002; Fohrer, et al ., 2002; Sullivan et al ., 2004) and long‐term climatic change (Gleick, 1987; Vörösmarty & Moore, 1991; Rind et al ., 1992; Nikolaidis et al ., 1993; Xu, 2000). If the modelling includes the dynamics of carbon, nutrients and silt it might be useful as a semimechanical tool to quantify material transport and nonpoint pollution processes (Vörösmarty et al ., 1989; Olivera, 1996).…”