Akademik Veri Yönetim Sistemi
American Geophysical Union, Fall Meeting 2001, California, Amerika Birleşik Devletleri, 10 - 14 Aralık 2001, cilt.1, ss.1
The simulation of groundwater use in coastal areas
requires consideration of seawater intrusion, and optimization can involve
maximizing the total pumping rate subject to hydraulic and environmental
constraints. Groundwater models that represent freshwater and saltwater as
immiscible fluids separated by a sharp interface have been utilized for
simulation as well as variable density models that combine the groundwater flow
equations with contaminant transport advection-dispersion equations. The
response of an aquifer system can be linked to an optimization model by means
of the response matrix method, in which influence coefficients representing the
responses of heads and chloride concentrations to pumping are determined. In
this investigation, the variable density, finite-element numerical code SUTRA
(Saturated-Unsaturated Transport) was used to simulate a vertical cross-section
of the coastal aquifer system in the Goksu Delta at Silifke, Turkey. Chloride
concentrations in the groundwater model range from 0 mg/L in the freshwater to
22,000 mg/L, which represents Mediterranean seawater that has intruded into the
aquifer along its bottom boundary. It was assumed that pumping occurs from two
wells along the cross-section, and aquifer response coefficients were generated
at these two specific well locations using the groundwater model. A linear
optimization model was constructed under steady-state conditions to maximize
the total pumpage from the two wells subject to water demands and chloride
concentration and drawdown limitations. The GAMS (General Algebraic Modeling
System) code was used to execute the optimization model, and a trade-off curve
was constructed to relate the maximum allowable pumping rate from each well to
various chloride concentration levels.