An alternative policy option for reducing risk of natural catastrophe is relocation. Relocation is an important problem to cities which were seriously affected several times from destructive earthquakes. A comprehensive study of alternative regions for settlement in Adapazari in Turkey was carried out. A group of researchers prepared an extensive land use research project to identify geologically appropriate region options for possible future use. The researchers submitted ten candidate regions to be selected as the efficient site. In this study, the author summarizes the decision-making processes that an expert group followed. Two-stage decision-making approach was used to select the efficient site. At the first stage all the sites were evaluated by means of multi criteria decision analysis (MCDA). At the second stage, using the SPAN (Social participatory Allocative Networks) process for the efficient site was found at the end of evaluating a panel of experts from several disciplines. A Web based group decision support system was used for sequential computational process, quick communication, and sensitivity analysis. © INTERNATIONAL JOURNAL OF INDUSTRIAL ENGINEERING.