HR: 17:45h
AN: H24F-08    [Abstracts]
TI: Modeling groundwater-surface water interactions in an operational setting by linking object- oriented river basin management model (RiverWare) with 3-D finite-difference groundwater model (MODFLOW).
AU: Valerio, A
EM: allison.valerio@colorado.edu
AF: CADSWES, 421 UCB 1777 Exposition Drive University of Colorado, Boulder, CO 80309, United States
AU: * Rajaram, H
EM: hari@colorado.edu
AF: Civil Engineering - Department of Civil, Environmental and Architectural Engineering, Engineering Center ETOC 441 UCB 428 University of Colorado, Boulder, CO 80309, United States
AU: Zagona, E
EM: zagona@colorado.edu
AF: CADSWES, 421 UCB 1777 Exposition Drive University of Colorado, Boulder, CO 80309, United States
AB: Accurate representation of groundwater-surface water interactions is critical to modeling low river flow periods in riparian environments in the semi-arid southwestern United States. As an example, over-appropriation of human water use in the Middle Rio Grande region adversely impacts the habitat of the endangered Rio Grande silvery minnow. Improved management practices during low flow conditions could prevent channel desiccation and habitat destruction. We present a modeling tool with significant potential for improved decision-making in stream reaches influenced by significant surface-groundwater interactions. While river basin management models typically represent operational complexities such as human elements of water demand and consumption with a high degree of sophistication, they often represent groundwater-surface water interactions semi-empirically or at coarse resolution. In contrast, distributed groundwater models, with an adequately fine grid represent groundwater-surface water interactions accurately, but seldom incorporate complex details of water rights and user demands. To best exploit the strengths of both classes of models, we have developed a link between the object-oriented river management software package RiverWare and the USGS groundwater modeling program MODFLOW. An interactive time stepping approach is used in the linked model. RiverWare and MODFLOW run in parallel exchanging data after each time-step. This linked framework incorporates several features critical to modeling groundwater-surface interactions in riparian zones, including riparian ET, localized variations in seepage rates and rule-based water allocations to users and/or environmental flows, and is expected to be an improved tool for modeling groundwater-surface water interaction in regions where groundwater storage repose to changing river conditions is rapid. The performance of the linked model is illustrated through applications on the Rio Grande in the vicinity of Albuquerque, New Mexico. Low river flow conditions are simulated in a high resolution linked model at several projected future scenarios of the region.
DE: 1830 Groundwater/surface water interaction
DE: 1847 Modeling
DE: 1876 Water budgets
DE: 6334 Regional planning (1880)
SC: Hydrology [H]
MN: 2007 Fall Meeting