HR: 0800h
AN: H41D-0442    [Abstracts]
TI: Aquifer Recharge Assessment from Surface Ecohydrological Conditions: A Spatial Analysis along an Ecotonal Gradient in New Mexico
AU: * Gutierrez-Jurado, H A
EM: hugo@nmt.edu
AF: Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 United States
AU: Vivoni, E R
EM: vivoni@nmt.edu
AF: Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 United States
AB: Semiarid areas in the American Southwest face pressing water sustainability issues that are aggravated by changes in land cover, which may further affect the water cycle in the region. For example, recent drought conditions have led to widespread decreases in woodland coverage in northern Arizona and New Mexico. The majority of these areas rely on groundwater supplies to satisfy their current water needs. As a result, the assessment of current recharge in semiarid regions is becoming increasingly important. This study evaluates the relationship between land cover features and the potential for groundwater recharge, defined here as infiltration past the root zone. We present a new technique for characterizing surface features as a first indication of recharge potential using spatially distributed landscape properties and a soil water bucket model based on ecohydrological dynamics. Because conventional models do not account for the effect of topographic position, we incorporate a term representing the influence of site geomorphology on groundwater recharge. The model is parameterized based on landscape properties including terrain position, vegetation characteristics, and soil properties. We force the distributed model using stochastically-generated rainfall based on regional, long-term precipitation data. A case study is presented for a semiarid area of northern New Mexico exhibiting an ecotonal gradient along an incised, mountain front (e.g. transition between conifer woodland to desert shrubs). Results are compared to previous recharge estimates and recently developed infiltration maps. After model testing, we present a set of scenarios depicting current land cover changes in the region in order to assess potential recharge alterations for the area. The major advantages of the technique are illustrated, including its capability for mapping groundwater recharge over large, heterogeneous domains using readily available geospatial datasets.
DE: 1813 Eco-hydrology
DE: 1819 Geographic Information Systems (GIS)
DE: 1824 Geomorphology: general (1625)
DE: 1875 Vadose zone
DE: 1894 Instruments and techniques: modeling
SC: Hydrology [H]
MN: Fall Meeting 2005