Land suitability analysis for natural wastewater treatment systems using a new GIS add-in for supporting criterion weight elicitation methods

Renowned for their ability to deal with spatial problems, commercial GIS software packages can play crucial role in spatial decision making processes, provided that they have tools that allow both private and public organizations to manage and analyze spatial referenced data. In particular, land-use suitability analysis applications are valuable, where the use of conflicting objectives and decision maker's (DMs) preferences is common practice. In order to expand GIS abilities to the consideration of decision criteria, OR/MS researchers during the last two decades strongly pronounce in favor of developing synergies between GIS and multicriteria decision making tools. After a short but comprehensive guide to the processes involved in multicriteria suitability analysis applications, the main objective of the paper is to present an add-in to ESRI's ArcGIS environment that supports hierarchical formations of the decision problem, and a variety of procedures for decision criteria weight estimations. The prototype allows suitability index estimations for ordering alternatives using as decision rule the Weighted Linear Combination. Finally, the add-in is used in a real case study, in which we propose a procedure for finding out suitable candidate locations to implement natural systems for the wastewater treatment in the Evros Prefecture-Northeast Greece.