Using Marxan in IDRISI
To access Marxan you need to go to the following Menu System, Marxan cannot be accessed like your other modules from the search box but it can be searched in the Help System.
Navigate to the Land Change Modeler as shown above. (Modeling|Environmental/Simulation Modeling|Land Change Modeler)
When you get the above menu you need to select the Planning TAB (Top Second from Left).
You will now get the following menu:
Where you see the first Marxan click on the downward arrow
To do the Marxan Tutorial please go through Exercise 6-6 of the Idrisi Tutorial (HBM: RESERVE SELECTION WITH MARXAN).
Ensure you have changed the Project to point to the Marxan Tutorial data. You need to search you specific PC to find “marxan”. On my PC it is located in the following folder: C:/ Program Files (x86)/IRDRISI Selva/Tutorail Data/IDRISI Tutorial Data/LCM/Marxan
Ensure you understand the following concepts first:
1)Planning Unitraster file (and in this case it is made from a Land Cover and a Catchment layer so is representative of an Ecological Planning Unit). Each planning unit itself must have a unique number otherwise the program won’t run. If this is not the case you need to run the GROUP module so that becomes the case.
2)Protected Areas raster file
3)Planning Unit Tenureraster file: This specifies which locations are available for selection in the final reserve system. Bu default it EXCLUDES the Protected Areas since they are already within the Protected Area Network. It also excludes areas that have been transformed and unlikely to hold any value for biodiversity conservation.
- If a location has a value of 0, it may be selected in the initial Protected Area Network (or Reserve System).
- If a location has a value of 1, it will be included selected in the initial Protected Area Network (or Reserve System).
- If a location has a value of 2 it is already assigned as part of the initial Protected Area Network (or Reserve System).
- If a location has a value of 3 it will be excluded from selection (this means you don’t have to work about masking out areas outside your country) if the Planning Unit Tenure files is correctly formatted.
4)Conservation Targets Raster files. These can only have a value of 1 where either a Landuse/cover class or a species is present or 0 where it is absent. You should have at least 20 Conservation Targets and have some that are representative of each type of species: Endemic, Critically Endangered, Endangered and Rare, Vulnerable, Charismatic, Keystone, Top Predator, plus have some Ecosystem/Habitat targets.
5)Species Penalty Factor SPF (we did this in Florida conservation exercise). This is a value given to a particular species or group of species to indicate how important it is for inclusion in the Protected Area Network. The higher the value, the more likely the species’ target is met. There is no fixed rule on how to determine this value. Initially run all Targets with a fixed SPF such as 10. If the Targets are not met you will need to change these.
6)Boundary Length: This defines the reserves compactness and is important if you want to consider this is in the final preparation of the Protected Area Network.
7)Land Cost Layer Raster file: This layer specifies the cost of including the planning unit in the Protected Area Network
Undertake the Tutorial Exercise 6-6 and make sure you read through it fully.
Ensure that you have made a Project directed to using the folder Marxan. You will note that this exercise deals with undertaking a Conservation Plan for Bolivia based on 73 Endemic Species which are the Targets.
View in Idrisi the following files:
1)BOLIVIA_LU Bolivia Landuse
2)BOLIVIA_ROADS Bolivia Roads with a 5 km buffer
3)BOLIVIA_PA Bolivia’s Protected Areas
4)BOLIVIA_PROV Bolivia’s Administrative Areas (Provinces)
5)BOLIVIA_BASIN Bolivia’s River Basins or River Catchments
6)BOLIVIA_ECO Bolivia’s terrestrial Ecoregions
7)PU_TENURE Planning Unit Tenure Fie: This tells Marxan which Planning Units are to be considered to complement the exiting Protected Area Network and which Planning Units have not biodiversity value due to being too transformed.
8)PU_TENURE_PAASSESS Planning Tenure File which only evaluates what is conserved in the Protected Areas Network.
When completing the first Dialog Box it should look as below: This is the Marxan: Input and Output configuration.Then use the down arrow to get to the Second Marxan Dialogue which is the Marxan Parameters.
This particular configuration allows you to assess how much your existing Protected Area Network conserves in terms of your identified targets.
Now you need to identify what Planning Units need to be added to the existing Protected Areas Network so as to develop a systematic conservation plan. Please go through the rest of the tutorial. The dialogue box should as below:
Extra Technical details – if Marxan does not seem to work on your PC
Marxan is not a actually a module in IDRISI. The consequence of this is that you cannot simply type in Marxaninthe search box and a dialogue box comes up. In fact you actually have to load a separate executable program up first. Neil said he had done this for all the PCs but in case it has not been done on your PC here are the Instructions:
Only Marxan version 1.8.10 works in Idrisi and is no longer available from the University of Queensland. I have therefore uploaded it to my FTP server.
Here is the link to the zipped file of the Marxan executable file.
There is also a help file that I made to go with this. Marxan_extract_Help.doc
The Marxan.exe (unzipped from the above link) must be located in the Mods folder under IDRISI's program directory. If the exe file is not found in the folder, an error message as below will appear stating that the marxan.exe is not found in the directory.
If you get this message it means that Marxan is not loaded in your Mods folder. You must copy the marxan executable file to this folder (see below).
Idrisi should now be able to run the executable file marxan that is in this folder.
For this part of the assignment please use the Lab-machines as they are using 32-bit Windows operating system. I was not able to get marxan to run on my 64 bit - I naorrowed it down to the Marxan not working rather than the Idrisi Selva.