Marxan site selection tool

The Marxan site selection tool helps to weigh the costs and benefits associated with various site selection options.

The Marxan site selection tool helps to systematically identify possible locations for specific uses or nature conservation. It can help to rate the trade-offs associated with the proposed solutions. Originally developed to help to optimize a network of Marine Protected Areas, the tool and the extension Marxan with Zones can be applied in spatial decision-making in MSP. Marxan is designed to find the most suitable area for set targets while avoiding costs or conflicts caused by other uses or nature protection. This enables the planner to compare a range of scenarios for the different and thereby to compare different options for spatial designations.

The image below shows the results of one scenario for applying Marxan for site selection for offshore wind farms. In this case, the target was energy production supported by wind availability. As spatially varying costs, foundation and cable length were used and nature protection, shipping and the visual obstruction close to the coast as conflicts.

Marxan delivers a systematic approach and a transparent methodology. Furthermore, a huge variety of planning scenarios can be saved and repeatedly accessed. Marxan is useful for the planning phase as well as for displaying and discussing different options with stakeholders. Please find the Training Tutorial how to use Marxan in MSP in the following movie:

In BaltSpace, Marxan was applied for a complex study identifying potential new MPA areas in the Danish Baltic Sea around Bornholm. This real case gave the opportunity to evaluate the application of Marxan by employees from the Danish Ministry for Environment and Agriculture, the Nature Agency and the Foreign Ministry. The application of Marxan was tested together with Zonation (another conservation planning  tool) and other models. Additionally, we evaluated several Decision support tools via an online survey.

The evaluations will be included in the forthcoming Report 3.3 Handbook on approaches and tools.