In the second half of Module 6, we built upon the knowledge obtained in Scenario's One and Two: reclassifying raster datasets to generate a Suitability Map. From there, we were able to continue analyzing the datasets to obtain a Least Cost Path. A Least Cost Path analysis is a geoprocessing workflow that determines the lowest cost path from a source location throughout an entire dataset. As stated in the first post for Module 6, 'cost' is a relative term that does not necessarily refer to monetary units; however, in the map below, a Least Cost Path analysis was performed for an oil company wishing to install a pipeline through a southwestern portion of the state of Oregon. Once the datasets have been reclassified and combined using the Weighted Overlay tool, a Cost Distance function can be run to determine the cost from a set source location. As shown in the map below, the Least Cost Path is derived from the Cost Distance output, and the dashed line represents the lowest-cost route through the study area. Like the Suitability Map, factors can be weighted to give priority to some criteria over others. For instance, the bottom-left map in the image below provides a Least Cost Path based on slope alone. However, if cost is added for river crossings, the Least Cost Path is drastically altered to minimize the number of times the pipeline crosses the rivers in the area [see bottom-right map below.]
Another type of map that provides least cost information is a Corridor Analysis map; a Corridor Analysis map determines an area, or corridor, of least cost between two points; the Corridor analysis does not take direction into consideration. As illustrated in the Corridor analysis map, the Least Cost Path falls within the lowest classification of the corridor area. This would provide the oil company of an area to build the pipeline within, allowing them to make final decisions regarding pipeline installation while maintaining cost efficiency.
Lastly, in Scenario 4, all of these processes were applied to create a Corridor analysis on travelling bears throughout Coronado National Forest. While no new processes were added to the workflow involved in creating this map, it was a great opportunity to apply all tools / functions in a cumulative effort to produce the deliverable below. I was quite happy with this deliverable and believe it to be an outstanding representation of my comprehensive understanding of Suitability Mapping, Least Cost Path Mapping, and Corridor Analysis Mapping.
No comments:
Post a Comment