Expected Use Macro

The expected-use macro developed for IDRISI 32 is slightly different than the macro developed for IDRISI for Windows 2.

The expected-use macro for IDRISI 32 has 13 steps, and incorporates the "place holder" capability offered by IDRISI 32. To operate the expected-use macro three coverages are required, as well as a name for the resulting expected-use coverage. The three coverages required are:

  • A slope map of the entire analysis area with slope values in percent. The slope map is also utilized as the basis for the reference coordinates of the resulting expected-use coverage.
  • A water sources coverage with livestock watering points given a value of 1.
  • A pasture polygon coverage for the individual pasture being analyzed, with the pasture having a value of 1, and the rest of the area a value of 0.

Additionally a customized palette named "expected use.smp" for displaying the expected-use coverage is utilized. Wildland Solutions utilizes a palette with the following values:

  1. The areas of concentrated use are given a value of 1 and shown as pink.
  2. The areas of moderate use are given a value of 2 and shown as yellow.
  3. The areas of light use are given a value of 3 and shown as blue.
  4. The areas of slight use are given a value of 4 and shown as green.
  5. The areas of incidental use are given a value of 5 and shown as gray.

The place holders designed into the expected-use macro for IDRISI 32 are as follows:

  • %1 is the slope map coverage developed for the analysis area.
  • %2 is the water points coverage developed for the pasture being analyzed.
  • %3 is the polygon coverage developed for the pasture being analyzed.
  • %4 is the name assigned to the expected-use map that will be produced for the pasture being analyzed.

Note: To make the data more informative and easier to understand line 12 of the macro reclasses each pixel into one of 5 expected use classes. The breaking point between class1 (concentration area) and class 2 (moderate use) is rather sensitive. If the class break point is established as 1.98, the result is that moderate use is assigned to pixels that are more than 450 yards from water on slopes less than 6%. If the class break point is established as 1.99, the result is that moderate use is assigned to pixels that are more than 350 yards from water on slopes less than 6%. If the class break point is established as 1.999, the result is that moderate use is assigned to pixels that are more than 280 yards from water on slopes less than 6%.

-----Expected-use Macro for use with IDRISI 32-----

INITIAL X PX-MWPT*1*1*0*1*%1
POINTRAS X %2*PX-MWPT*1
DISTANCE X PX-MWPT*PX-WTDS
INITIAL X PX-POLY*1*1*0*1*%1
POLYRAS X %3*PX-POLY
OVERLAY X 3*PX-WTDS*PX-POLY*PX-WTDC
FUZZY X 1*PX-WTDC*1*PX-WTDZ*200*200*200*3200
OVERLAY X 3*%1*PX-POLY*PX-SLPC
FUZZY X 1*PX-SLPC*1*PX-SLPZ*6*6*6*45
OVERLAY X 1*PX-WTDZ*PX-SLPZ*PX-SU
OVERLAY X 3*PX-SUT*PX-POLY*PX-SUIT
RECLASS X I*PX-SUIT*%4*2*1*1.99*2.02*2*1.7*1.99*3*1.35*1.7*4*1.05*1.35*5*0.0001*1.05*-9999
DISPLAY X n*%4*expected use*n

**Property of Keith Guenther and Wildland Solutions