Volume No. 8 Issue No.: 1 Page No.: 115-123 Jul-Sept. 2013

 

SENSITIVITY ANALYSIS ON INPUT PARAMETERS OF 1-D GROUNDWATER FLOW GOVERNING EQUATION : SOLVED BY FINITE-DIFFERENCE AND THOMAS ALGORITHM IN MICROSOFT EXCEL

 

Goh E.G.*1 and Noborio K.2

1. Department of Engineering Science, Faculty of Science and Technology, Universiti Malaysia Terengganu (UMT), Kuala Terengganu, Terengganu, (MALAYSIA)
2. School of Agriculture, Meiji University, Kawasaki, Kanagawa (JAPAN)

 

Received on : March 22, 2013

 

ABSTRACT

 

One of the famous groundwater flow program is MODFLOW. It has been coupled with MT3DMS, by Guo et al. to develop a new program, i.e. SEAWAT, to enable variable-density groundwater flow simulation. In SEAWAT, prior coupling groundwater flow equation with solute transport equation, the governing equation of groundwater flow was modified. In the current work, the modified equation was discretized as in SEAWAT, and solved by Thomas algorithm (Direct method) in Microsoft Excel. A simple hypothetical case study was established from previous work by Goh and based on its input parameter default value and possible data range. This is followed by steady-state simulation and verification of the flow equation by analytical solution. Unsteady-state simulation was carried out to determine the sensitivity analysis on each parameter, i.e. hydraulic conductivity, porosity, water compressibility, porous material compressibility and water density. The sensitivity analysis was based on the time required for hydraulic head drawdown to recover to its original level. The current study found out that the parameters can be categorized into either linear or non-linear and either positive or negative relation.

 

Keywords : Groundwater flow governing equation, Sensitivity analysis, Normalized sensitivity coefficient, MODFLOW, SEAWAT

 

 

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