Site selection suitability assessment for protective artificial reefs in island area

There were more than thirty countries and regions which placed artificial reefs in coastal areas. However, more than fifty percent of these Artificial Reefs failed due to improper site selection, lack of supervision and planning. Placing the Artificial Reefs consumes large amount of time and finances which means that it’s impossible to change Artificial Reefs location. Therefore, the success of Artificial Reefs depends on the site selection. Most studies of Artificial Reefs focused on their ecological effects, and these results could be used for evaluating the effectiveness, but they did not provide necessary references for Artificial Reefs site selection. For assessing the site selection suitability of Artificial Reefs, our study took island area protective Artificial Reefs site selection as the theme and the Multi-Criteria Decision Method was used in this study. Expert system, Analytic Hierarchy Process (AHP), GIS spatial analysis and raster calculation were also combined. The effective main criteria (physical, biological and management) and sub-criteria (bottom slope, substrate, current, depth, catch, density, larval dispersal, existing larvae, distance to pollution source, distance to channel, distance to coastline) for protective Artificial Reefs were identified by paper reviewing and expert knowledge. Using the pair-wise comparison and AHP, the weight of main criteria and sub-criteria were ranked, and the results showed the weight of physical, biological and management were 0.481, 0.405, 0.114 respectively. The weight of sub-criteria were corresponding 0.101, 0.186, 0.097, 0.098, 0.095, 0.184, 0.048, 0.079, 0.068, 0.030, 0.016. The site selection suitability in Ma’an Archipelago showed spatial heterogeneity after calculating overlapped criteria map. The corresponding analysis of depth, substrate type, resource density distribution and suitability distribution showed that the model results were consistent with the suitability criteria. And the high suitability areas where Artificial Reefs have been placedalso showed effectiveness. Therefore, the assessment model of this study could be used for assessing the site selection suitability of protective artificial reefs in similar island areas.