| Author | Xu, Qiang |
| Call Number | AIT Thesis no.WM-95-31 |
| Subject(s) | Aquifers
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-95-31 |
| Abstract | Planning and operation of a multi-aquifer system under multiobjectives is a complex topic
in groundwater management due to its dimensionality problem and involvement of decisionmakers'
attitude and preference. Therefore, an efficient management technique is urgently needed
when a large multi-aquifer system is planned and operated under multiobjectives.
In this study, a multiobjective groundwater management model has been developed. Three
conflicting objective functions, maximizing total pumping benefit, maximizing total pumpage, and
minimizing maximum land subsidence in the context of pumping requirements and piewmetric
head requirements, were proposed to evaluate groundwater management alternatives. The model
is solved in hierarchy approach. The constraint method was used to generate a discrete set of
nondominated solutions. Multicriterion decision making technique, Compromising programming, ,
was used to analyze the computed discrete set of alternatives.
In the combination of groundwater model and multiobjective management model, unit
response functions have been used as a major tool. The unit response functions developed and
employed in the solution of the model are 'drawdown unit response function', 'dissipation unit
response function' and 'land subsidence unit response function '. Finite difference scheme is
employed to generate drawdown unit response function of a multi-aquifer system using
'MODFLOW'. Dissipation unit response function of aquitards is generated by simply developed
explicit scheme of finite difference method. A numerical technique, first used in this study, has
been developed to generate land subsidence unit response function using concept of convolution,
combining drawdown unit response function of aquifers and dissipation unit response function of
aquitards by taking drawdown unit response function of aquifers as general head boundary. Both
drawdown and land subsidence unit response functions were verified by the results of direct
simulation using implicit scheme of finite difference method with 'MODFLOW'.
The concept of 'active and inactive model well (cell)' developed in this study helps great
for cmoputer programming when the developed multiobjective hierarchical model is applied to a
large multi-aquifer system where large data files have to be dealt with.
The management model has been applied to the real world problem of Bangkok Aquifer
System as a case study. An optimum pumping policy for the system for the next 10 years (1996-
2005) has been obtained for each single objective satisfying the pumping and head constraints at
different locations. For complete demonstration of the model application, the model has been
applied to the Bangkok Aquifer System with an increased pumping cost rate for evaluating a
discrete set of noninferior alternatives. Both pumpage and pumping pattern (in space and time) for
each discrete noninferior alternative was presented. Best recommended alternatives of the
multiobjective model were selected by compromising programming with subjective attitude and
preference of decision makers. |
| Year | 1996 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-31 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Gupta, Ashim Das |
| Examination Committee(s) | Huynh Ngoc Phien;
Ammentorp, Hans Christian |
| Scholarship Donor(s) | German Academic Exchange Service (DAAD) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology |