|
KMID : 1024520090180090971
|
|
Journal of the Environmental Sciences
2009 Volume.18 No. 9 p.971 ~ p.981
|
|
|
Prediction of Water-Quality Enhancement Effects of Gates Operation in the West-Nakdong River Using RMA2/RMA4 Models
|
|
Lee Keum-Chan
Yoon Young-Sam
Lee Nam-Joo
|
|
|
Abstract
|
|
|
|
An objective of this study is as follows: 1) performing sensitivity analysis and parameter estimation of RMA2 and RMA4 models for the West-Nakdong River, 2) drawing up alternatives of gates-operation for water-quality enhancement, and 3) quantitative evaluation of methodology of ’flow-restoration by gates-operation’ among ’Comprehensive Plan Improving Water-Quality in the West-Nakdong River(WNR)’ with the target water-quality(BOD at Nakbon-N point: below 4.3 mg/L). The parameters for the RMA2 (depth-averaged two-dimensional flow model) and RMA4 (depth-averaged two-dimensional water-quality model) were determined by sensitivity analysis. Result of parameter estimation for RMA2 and RMA4 models is of the eddy viscosity, 20 of the Peclet number, 0.025 of the Manning coefficient, and of the diffusion coefficient. We have evaluated the effects of water-quality enhancement of the selected alternatives by numerical simulation technique with the models under the steady-state flow condition and the time-variant transport condition. Because of no-resuspension from river bottom and considering BOD as conservative matter, these simulation results slightly differ from real phenomena. In the case of of Daejeo-gate inflow, two-dimensional flow pn results result represents that small velocity occurs in the Pyungkang Stream and no flow in the Maekdo River. In the WNR, there occurs the most rapid flow near timhae-bridge. In the WNR, changes of water-quality for the four selected simulation cases(6, 10, 30, of the Daejeo-gate inflow) were predicted. Since the Daejeo-Gate and the Noksan-Gate can be opened up to 7 days, it would be found that sustainable inflow of at the Daejeo-gate makes BOD in the WNR to be under the target of water-quality.
|
|
|
KEYWORD
|
|
|
the West-Nakdong River, Sensitivity analysis, Two-dimensional model, Gates operation
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|