000			04165nam a2200421 4500
005			20260818093959.0
008			170698 th eng
035			_a.b11509880
099		9	_aAIT Thesis no. WA-92-20
100	0		_aNguyen The Duy
245	1	0	_aDispersion coefficients in an estuarine network
260			_aBangkok : _bAsian Institute of Technology, _c1992
300			_a143 leaves
490	1		_aThesis ; _vno. WA-92-20
500			_aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology
502			_aThesis (M.Eng.) - Asian Institute of Technology, 1992
520			_aThis study presents two models including theories and numerical procedures to determine the dispersion coefficient, a very important parameter, for the prediction of salinity intrusion in estuarine networks. The First Model (Trial Method) is established based on a trial process to find out the most appropriate form of the dispersion coefficient as a function of specified system parameters. In this model, the problems of formulating an expression for the dispersion coefficient and determining salinity concentration at the river sections are solved simultaneously for the whole river system. The results obtained from this model show that the dispersion coefficient distribution D(x,t) along the main branches of the Mekong river system depends upon the salinity and its gradient and can be represented well by the expression D k s as 3 ax Due to the larger variation in time of the salinity gradient magnitudes when comparing with the salinity concentration magnitudes, the salinity gradient is proved to play the most important role on the mixing process between sea and river water and has a primary effect on the behavior of the dispersion coefficient, while the salinity concentration has a secondary effect on the variation of this coefficient. From the computational results, it can be also seen that there is no large variation in the magnitudes of the relation coefficient k3 although its value depends on a lot of factors. The Second Model (Backward Method) is established to determine discrete values of the dispersion coefficient in terms of nodal dispersion coefficient, using observed data of salinity concentration at internal stations on the river system. The results obtained from this model show that the magnitude order of the dispersion coefficient for Mekong estuarine network varies widely in space and in time; its maximum can reach a value up to 3,500 m2 /s, while the magnitudes fluctuate mainly in the range of 0-1,500 m2 /sec. In general, the magnitudes of the dispersion coefficient vary in the same manner as those of the salinity concentration, i.e. the dispersion coefficient at the stations in the area in dry season increases from January to April and decreases after April.
650		0	_aDiffusion in hydrology
650		0	_aEstuaries _xMekong Delta
700	0		_aSuphat Vongvisessomjai, _eChairperson
700	0		_aTawatchai Tingsanchali, _eExamination Committee
700	1		_aTanaka, Hitoshi, _eScholarship Donor
710	2		_aThe Government of Switzerland, _eScholarship Donor
810	2		_aAsian Institute of Technology. _tThesis ; _vno. WA-92-20
856			_3Full-Text _uhttp://203.159.5.9/ait-thesis/detail.php?q=B17282
907			_a.b11509880 _bmnait _cs
902			_a240404
998			_b0 _c960620 _dm _ea _fs _g0
945			_lmnait
945			_lmnait
945			_lmnarc
942			_c20
942			_c40
909			_aBarcode : 30050003055356 _bCREATED : 1995-01-21 _cRECORD # : i11785780 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
909			_aBarcode : 30050003055349 _bCREATED : 1995-01-21 _cRECORD # : i11785792 _dLPATRON : 1014029 _eLCHKIN : 2000-10-21 _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 4 _jTOT RENEW : 0
909			_aBarcode : 30050160033170 _bCREATED : 2016-02-15 _cRECORD # : i12882562 _dLPATRON : 0 _eLCHKIN : - _f# RENEWALS : 0 _g# OVERDUE : 0 _hIUSE3 : 0 _iTOT CHKOUT : 0 _jTOT RENEW : 0
999			_c30906 _d30906