American Water Resources Association 2010 Summer Specialty Conference: GIS & Water Resources VI, 29 – 31 March 2010, Orlando, Florida
Session 4: Hydrologic Modeling I. Monday, 29 March, 1:30 p.m. – 3:00 p.m.
Julie Coonrod, Department of Civil Engineering, Albuquerque, NM (co-authors: Kelly Isaacson, Venkatesh Merwade)
“River restoration projects in the vicinity of Albuquerque, New Mexico are often focused on the riparian forest. Exotic species are removed, while native cottonwood trees are planted. The cottonwood trees are ‘pole planted’ such that their roots tap into the groundwater table adjacent to the river. Such projects are located anywhere current cottonwood trees exist and not necessarily where groundwater depths have been estimated to determine likelihood of species survival. This work is aimed at utilizing Geographic Information Systems (GIS) along with the Hydrologic Engineering Center River Analysis System (RAS) to determine depth to groundwater as a function of river flow rate. The RAS model utilizes a terrain model developed by various data sets including point data from Light Detection and Ranging, surveyed cross-section points, and aerial photographs. The RAS model is calibrated with readily available flow gage data. In-channel water surfaces from RAS are combined with well data in GIS to create groundwater surfaces. The groundwater surfaces are thus created as a function of flow rate. Doing so allows for simulation of groundwater surfaces for average years, dry years, and wet years. Furthermore, climate change scenarios (that employed GIS methods) can be used to estimate changes in stream flow. These changes show the groundwater surface can drop below the depth that the cottonwood trees can reach. By subtracting the groundwater surface from the digital terrain, the depth to groundwater is determined. Locations where riparian vegetation will be most stressed can be identified.”