| Author | Nobi, Nur |
| Call Number | AIT Diss. no. WA-94-17 |
| Subject(s) | Water quality management--Bangladesh, Southwest
|
| Note | A Dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WA-94-17 |
| Abstract | Regional water resources management and development problems of integrated streamaquifer systems in coastal regions involve various interrelated aspects: At the same time, the problems are highly non-linear and complicated due to the involvement of a complex salinity intrusion mechanism as well as the dynamic interactions between streams and aquifers. An analytical framework has been developed to obtain the optimal development policies for the coastal stream-aquifer systems with emphasis on the integrated use of the surface water and the groundwater. The criteria considered for optimal policies are maximization of economic benefits and the minimization of saltwater intrusions. Under a multiobjective framework of analysis, the optimal spatial and temporal allocations of surface water and groundwater along with the optimal cropping patterns are determined. In addition, the optimal extent of land improvement, optimal diversions from the external sources, and the optimal development of brackish water shrimp culture in tidal influence zones are also determined. A numerical model for the simulation of the flow and solute transport (salinity intrusions) in the rivers and the aquifer incorporating the dynamic interactions between the rivers and the aquifer is developed. The simulation model comprises of a two-dimensional depth average finite element model of the aquifer and a quasi-steady node and branch model of the river network linked together by a linear relation for the flow exchange. To analyze the management problem, a hierarchial model has been formulated by linking the simulation model with a non-linear optimization technique. The management model has been formulated based on the multilevel decomposition approach to overcome the dimensionality problems associated with such large scale problems and also to obtain an efficient solution procedure. The methodology has been successfully applied to the real world management problems of the integrated stream-aquifer system of the Southwest Region of Bangladesh. Various development scenarios for the region are investigated. The region has a significant potential for further water resources development. It has been observed that the interactions between the rivers and the aquifer of the region significantly influence the flow and salinity intrusion in the system. It has been found that the control of salinity intrusion in the region is in direct conflict with the availability of irrigation water and this subsequently influences the decisions of irrigation development and land improvement in the area. |
| Year | 1994 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WA-94-17 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Resources Research Engineering (WA) |
| Chairperson(s) | Gupta, Ashim Das; |
| Examination Committee(s) | Harboe, Ricardo;Ammentorp, Hans Christian;Paudyal, Guna Nidhi;Huynh Ngoc Phien;Onta, Pushpa Raj;Mays, Larry W.; |
| Scholarship Donor(s) | The Government of Japan; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1994 |