Use of the inverse modeling technique in a groundwater flow model: Afyon-Şuhut Plain Evrik modelleme tekniǧinin yeraltisuyu akim modellerinde kullanilmasi: Afyon-Şuhut Ovasi


Dişli E.

Yerbilimleri/ Earth Sciences, vol.26, no.2, pp.33-47, 2005 (Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 26 Issue: 2
  • Publication Date: 2005
  • Journal Name: Yerbilimleri/ Earth Sciences
  • Journal Indexes: Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.33-47
  • Keywords: Hydraulic parameters, Inverse modeling, MODFLOW, PEST, Şuhut Plain, Sensitivity analysis
  • Van Yüzüncü Yıl University Affiliated: Yes

Abstract

In hydrogeological studies the, inverse modeling approach is based on nonlinear parameter optimization which minimizes the difference between the values of hydraulic head described in groundwater flow modeling and observed hydraulic head values. This approach has been applied to the hydrogeologic system of the Afyon-Şuhut Plain. This study consists of two stages. In the first stage, a conceptual hydrogeologic structure of the Afyon-Şuhut Plain is constructed. The Şuhut aquifer was discredited into four model layers in order to consider the vertical flow component. The model area is composed of seven hydrogeological zones, which represent the lithological units in each model layer. The hydraulic parameters are assumed to be homogeneous within each zone. Input and output files of MODFLOW were prepared and the parameters and hydraulic head values in these files were identified in the PEST nonlinear inverse optimization program. The aquifer parameters were then estimated by PEST These parameters were than compared with hydraulic conductivity values estimated by the evaluation of the pumping test data by Neumann method. The hydraulic conductivity of gravel and tuft units were calculated as 0.35 and 1.19 m/d by Neuman methods, 0.168 and 0.88 m/d by PEST As a result of sensitivity analysis, the simulated hydraulic head within the aquifer system in the Şuhut Plain is dominated by the hydraulic parameter of gravel and tuf units.