000 04191nam a2200397 4500
005 20260817161749.0
008 180698 th eng
035 _a.b11533985
099 9 _aAIT Thesis no.WM-95-04
100 1 _aNarasimhan, Sriram
245 1 0 _aAdvection dispersion analysis in the Upper Gulf of Thailand
260 _aBangkok :
_bAsian Institute of Technology,
_c1996
300 _a134 leaves :
_bill.
490 1 _aThesis ;
_vno. WM-95-04
502 _aThesis (M.Eng.) - Asian Institute of Technology, 1995
500 _aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering
520 _aIn the mathematical modelling of the diffusion or dispersion process caused by wastes or any pollutant, the diffusion coefficient plays an important role. In this study the diffusion coefficient is calculated using the statistical procedure of removing periodicity from the tidal current data using Harmonic Analysis. The Hydrodynamic and Water-Quality models based on Finite-difference formulations are used to study the variations of flow patterns and distribution patterns of some water quality parameters in the Upper Gulf of Thailand. The Hydrodynamic model is based on the conservation of water mass and momentum equations, vertically averaged over the whole water depth, while the dispersion model is based on the vertically averaged substance balance equation. The depth averaged two dimensional model is used to study the tidal circulation in a discrete representation of a continuum problem with a variety of computational procedures and boundary conditions which are currently available. By using the so-called Alternating Direction Implicit (ADI) finite difference scheme, a combination of implicit and explicit schemes, the numerical model is developed to achieve the proposed solutions. In this study the model is applied to two main areas of interest. One is the whole Upper Gulf and the other is the mouth of the Chao Phraya River. To test it's reliability the calibration of the results is performed and shows satisfactory comparison of observed and computed current speed and direction. The verification was also performed using the tidal current measured at an entirely different period of time. An attempt is made to develop a Water Quality model using finite-difference approximations and neglecting the decay term so that the pollutant can be assumed as unsettling mud. It was found from this Study that the Diffusion Coefficient along the North-South direction was higher than in the East-West direction which agrees well with the strong tidal Current condition in the Nmih-South direction in the area. There is also a need to study the reasons for the periodicity observed in the Auto-Correlation Analysis for the calculation of Diffusion Coefficient even after complete removal of the periodic components. The Study also revealed that the effect of the fresh water flows is restricted to a limited area in the vicinity of the river mouth and hence the flood water flows do not have a significant effect on the pollution of the entire Upper Gulf of Thailand
650 1 0 _aDiffusion in hydrology
700 0 _aSuphat Vongvisessomjai,
_eChairperson
700 0 _aSutat Weesakul,
_eExamination committee
700 1 _aHarumichi, Kyotoh,
_eExamination committee
700 1 _aHansen, Ian Sehested,
_eExamination committee
710 2 _aDANIDA,
_eScholarship donor
810 2 _aAsian Institute of Technology.
_tThesis ;
_vno. WM-95-04
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B15007
907 _a.b11533985
_bmnait
_cs
902 _a240516
998 _b0
_c960827
_dm
_ea
_fs
_g0
945 _lmnait
945 _lmnarc
942 _c22
942 _c40
909 _aBarcode : 30050120558670
_bCREATED : 2014-03-26
_cRECORD # : i12780911
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
909 _aBarcode : 30050160044797
_bCREATED : 2016-04-03
_cRECORD # : i12890212
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
999 _c2580
_d2580