Conservation assessments using CLUZ: steps 1 to 4

Step 1: Produce your planning unit theme

Your planning units can be any size or shape and I recommend reading the Define your planning units section before you produce your planning unit shapefile. Once you have decided on the type of planning units that are most suitable then follow these instructions:

To create a planning unit theme that represents real-world phenomena, such as land parcels or watershed sub-catchments, just use an existing ArcView shapefile that shows the boundaries of these polygons.

Alternatively, create square or hexagonal planning units by using the Repeating Shapes extension in ArcView.

To produce a planning unit theme that consists of your protected areas (PAs) surrounded by regular shaped polygons then follow these steps:

1. Create the planning unit theme using the Repeating Shapes extension.
   
   
2. Use your existing PA theme and add a field called "CLUZ_ID" to the PA theme table. Give each PA a unique identifier number.
   
   
3. Use ArcView's Union option in the Geoprocessing Wizard to combine the regular polygon planning units and the PAs into a new theme.
   
   
4. The new theme will divide each PA into a number of whole regular polygons and some fragments. Use the Dissolve option in the Geoprocessing Wizard to merge all these pieces into one polygon for each PA. In the Dialog Box, for the Select an attribute to dissolve input box choose the "CLUZ_ID" field.

Step 2: Create your blank CLUZ tables

The CLUZ tables describe the planning units, the conservation feature abundance data and the targets for each of the features. CLUZ will add all of your data to these tables, so the third step is to create the blank tables that will be used in the later processes.

Create the blank tables by using the following modules in the CLUZ menu:

Create unit theme from shapefile
Create blank target table
Create blank abundance table from unit theme

If you have a planning unit shapefile that contains existing unit ID values then give the existing ID field a name such as exist_ID, use the Create unit theme from shapefile module and then copy the values from exist_ID to the newly created Unit_id field.

Step 3: Input the planning unit cost data

The planning unit cost values can represent a range of phenomena, such as planning unit area or financial value, and I recommend reading the Decide on what the planning unit cost values should represent section before proceeding.

Always make sure that every planning unit has a cost value that is greater than 0. Otherwise, MARXAN might select a planning unit with no conservation or connectivity value, just because it has no cost and so does not increase the total planning unit cost.

The Create unit theme from shapefile module automatically calculates the area of each planning unit and also gives the option of using these values for the Cost field as well.

If you want to use a different measure of cost then independently produce a table showing the cost value of each planning unit, Join it to the planning unit theme table in ArcView and then copy the new values into the Cost field.

Step 4: Import your conservation feature distribution data

MARXAN and CLUZ can use data on a wide range of conservation features and I recommend reading the Select which conservation features should be included in the system section before proceeding. Next, you need to obtain maps showing each of these features and then import them into CLUZ. These maps could be in vector format (ArcView shapefiles), raster format (ArcView grids) or as tables that list the amount of each feature found in each planning unit (dBASE files).

Shapefile distribution maps can be imported directly into CLUZ using the Convert themes to abundance data module. Each shapefile must contain a field named ID, which lists the numeric ID value for each conservation feature.

Grid distribution maps need to be converted into dBASE tables showing the amount of each feature in each planning units using ArcView's Tabulate Areas module. These dBASE files can then be imported into CLUZ using the Import fields from table to abundance table module.

Once all of the abundance data are imported into CLUZ then you will need to open the Target table and add the names of each of the conservation features (either by typing them in or copying them from an existing table). Remember that MARXAN cannot process names that include numbers.