OCR Text |
Show 2.4 Summary Reasons for the preference of unit response formulations of groundwater optimization models, over the embedding formulations were enumerated in Section 1.2.1, While such formulations are easy to develop for the case of a confined aquifer with a linear partial differential equation governing flow, they are not readily forthcoming for stratified aquifer systems. The concept of the Girinski potential was shown to be a useful tool for the development of a linear approximation to the equation for flow in a stratified aquifer system. Unit response formulations for both the dewatering of and water supply from a stratified aquifer system were developed. For the water supply case, equations for relating ground water - surface water equations to the Girinski potential were also presented. Example applications of the dewatering model that compare to the situations analyzed by Aguado and Remson ( 1974,1980) for a confined aquifer and by Yeh ( 1982) for a stratified aquifer were also presented. The results for these examples ( including those with fixed costs) compare favorably in nature to those presented in the literature. The succeeding chapters contain models for groundwater management based on a unit response formulation with a confined aquifer. These models are capable of treating stratified aquifer systems with the Girinski potential used as the primary variable instead of the piezometric head in the confined aquifer. The modifications follow directly from the developments in this chapter. The only note of caution is with the applications to transient water management problems, where the restriction imposed on the validity of the Girinski potential linearization by equation 2.9 needs to be accounted for. 28 |