HR: 0800h
AN: H31C-1320 [Abstracts]
TI: Estimating Groundwater Recharge via a Deuterium-Calibrated Discrete-State Compartment Model
AU: * Hershey, R L
EM: ronh@dri.edu
AF: Division of Hydrologic Sciences, Desert Research Institute, 2215 Raggio Pkwy, Reno, NV 89512-1095
United States
AU: Earman, S
EM: searman@dri.edu
AF: Division of Hydrologic Sciences, Desert Research Institute, 2215 Raggio Pkwy, Reno, NV 89512-1095
United States
AB:
Increasing demand for water in southern Nevada is driving plans for large-scale interbasin water transfers. Knowledge of
groundwater recharge in the impacted basins is needed to assess how such withdrawals may impact water quantity and quality.
However, estimates of groundwater recharge in the western USA are typically not well constrained. The most common methods
for estimation of basin- (or larger) scale recharge are the Maxey-Eakin method (or some variant thereof) and calibration of
numeric models. For many parts of Nevada, recharge estimates using either of these methods are typically calibrated based on
estimated values for interbasin groundwater flow; these interbasin flow values have large inherent uncertainties, so
estimated recharge values based on these data have large uncertainties as well.
To estimate recharge for a large (3.4 x 1010 m2) area in south-central Nevada, we applied a discrete-state
compartment (DSC) model calibrated with δD data. Movement of water through the model cells is controlled by a series
of equations conserving mass. Because model calibration is based on measured values of δD instead of being based
entirely on estimated values, recharge fluxes derived from DSC model are independent of previously-extant estimates.
The DSC model estimate of total recharge for this area of southern Nevada is 5.3 x 107 m3/yr, compared with 3.1 x
107 m3/yr based on calibration of a MODFLOW model and 4.5 x 107 m3/yr based on Maxey-Eakin-type
estimates.
DE: 1806 Chemistry of fresh water
DE: 1829 Groundwater hydrology
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1847 Modeling
DE: 1884 Water supply
SC: Hydrology [H]
MN: Fall Meeting 2005