It is believed that a rare tree species is distributed in the regions with an altitude from 1100 to 1500m and on southeast facing slopes of 10-20 degrees. Which of the following is the right sequence of GIS operations for mapping the habitat potential of the species with the environmental envelope approach? (Suppose you were provided with DEM, slope and aspect raster layers.)
A) Reclassify the DEM, slope and aspect layers into multi-class maps respectively (with 1100-1500m as one of the classes on the reclassified DEM layer, southeast as one of the classes on the reclassified aspect layer and 10-20 degrees as one of the classes on the reclassified slope layer), and then overlay the three multi-class maps with the arithmetic operator 'Multiply'.
B) Reclassify the DEM, slope and aspect layers into multi-class maps respectively (with 1100-1500m as one of the classes on the reclassified DEM layer, southeast as one of the classes on the reclassified aspect layer and 10-20 degrees as one of the classes on the reclassified slope layer), and then overlay the three multi-class maps with the logic operator 'AND'.
C) Reclassify the DEM, slope and aspect layers into binary maps respectively (with 1100-1500m as 1 and others as 0 on the reclassified DEM layer, southeast as 1 and others as 0 on the reclassified aspect layer and 10-20 degrees as 1 and others as 0 on the reclassified slope layer), and then overlay the three binary maps with the logic operator 'AND' .
D) Reclassify the DEM, slope and aspect layers into binary maps respectively (with 1100-1500m as 1 and others as 0 on the reclassified DEM layer, southeast as 1 and others as 0 on the reclassified aspect layer and 10-20 degrees as 1 and others as 0 on the reclassified slope layer), and then overlay the three binary maps with the logic operator 'OR'.

Question

Quizplus · Accepted Answer

The best option is to reclassify the three input layers into binary maps with 1 representing the range of suitable values and 0 representing the unsuitable range. This is because the question requires mapping the environmental envelope of a rare tree species, which means identifying the specific conditions in which it can grow. The AND logic operator should be used to overlay the binary maps because the species can only exist where all three conditions (altitude, slope aspect) are present simultaneously.

It Is Believed That a Rare Tree Species Is Distributed