This paper presents a Geographical Information Systems (GIS)-based toolkit, developed for site comparison and ranking that can be used to facilitate the decision making process in second stage of the site selection process. The toolkit has been developed as an analytical component of a multi-criteria spatial decision support system for geoenvironmental and geoenergy applications. The methodology adopted to develop this analytical module is based on a systematic comparison of the surrounding areas of each site in accordance with key environmental, socio-economic and public-health indicators. The sites are ranked based on the most favorable key indicators using a Criterion Sorting Mechanism (CSM) or Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). An application of the site selection toolkit is presented in relation to an unconventional geoenergy development. The application exercise deals with the ranking of a number of potential sites for coalbed methane recovery in Wales, UK. The locations of potential sites are first selected with respect to the gas resource (techno-economic viability). The toolkit is then used to select and rank the potential sites based on key environmental indicators, in the site’s neighbourhood. The results of the site ranking using CSM and TOPSIS methods are compared and a number of scenarios are discussed. This approach of using a combination of site ranking methods along with the neighbourhood analysis reduces the risk of personal judgment and choice. The decisions on site selection can thus be evidenced on a quantified logic
