This week’s lab was a GIS challenge of challenges. Tough! It was the sheer length of the lab coupled with being unfamiliar with some of the geoprocessing tools while ensuring the correct parameters and inputs were set. Data not found after saving a completed map, even though the words echo when working in ArcGIS, “save and save often”. Yes, I saved and saved often. Several times ArcGIS crashed when running analysis tools or loading or adding data. I have had issues in the past when working in ArcGIS but this is above the rest with problems. Frustrating but it is what it is and there was much to be done.
Once again the data were provided for us, always helpful and I am grateful for that. Through this analysis, I will create map results for suitability and least cost analysis. There were several tools at our disposal as with ArcGIS there is usually more than one option to get the desired results. There were four scenarios with goals to achieve through different analyses.
As we progressed through the lab it was common to refer back to previous steps for reminders of how to prepare and analyze the data. The first scenario was preparation for the rest of the lab work as we worked to complete four total scenarios. The first step in a study is to state the problem. In doing this, you can break down the problem, establishing what data will be needed to complete the analysis. I used ModelBuilder in ArcGIS for Boolean Suitability in creating a flowchart. ModelBuilder helps present the visual of the data in one place in a clean and neat format. The primary data for this lab in each scenario was elevation, land cover, roads, and rivers. In each scenario the tool Reclassify was used to set values for the output. In completing the reclassification of data Boolean Suitability was applied, either it fits the criteria or it does not. Once completed the lab would offer 30 deliverables to turn in and along the journey, multiple geoprocessing tools would be used to create the deliverables.
 |
| ArcGIS ModelBuilder Boolean Suitability |
Scenario 1 - Identify cougar habitat and create a suitability map of cougar behavior
Data used: Slope (elevation data), land cover, roads, and rivers
Scenario 2 - A property developer wants an estimate of how much land would actually be able suitable to build on. Identify suitable locations for a developer to build on.
Data used: Land cover, soils, slopes, roads, and rivers
Scenario 3 - An oil company wants to install a pipeline and needs analysis on an area accounting for slope, river crossing, and river proximity.
Data used: Elevation–a DEM of the study area, Rivers–a vector version of rivers in the study area, Source–the origin of the pipeline, Destination–the destination of the pipeline, and Study area–polygon of the study area
Scenario 4 - Create a model of the potential movement of black bears between two protected areas, creating a corridor.
Data used: Coronado1 and Coronado2 – these are two existing areas of the Coronado National Forest, Elevation – elevation model for the study area, Landcover – land cover raster for the study area; the categories are described in the landcover_codes.dbf
File, and Roads – shapefile of roads in the study area
I created a corridor on the map but it is not visible due to technical difficulties. I reran the tools and it only seemed to get worse. It connects the two areas of Coronado National Forest which allows for the black bear to travel safely through the corridor between the national forests.
These scenarios offered a progression in necessary skills that involved much reading of ArcGIS help with details of how best to use a tool to achieve the best results. It can be a tedious and time-consuming process when you work and attend online school at the graduate level. It is also part of the learning process and aids in creative thinking to devise the best way to analyze the data. The ModelBuilder for Boolean Suitability set up at the beginning of the lab did help me visualize the analysis and what the outcome should be. I need more work with it but I see how it can be a timesaver in offering results more efficiently. For each scenario afterward I did not use the ModelBuilder. Reclassifying the data was involved in each scenario which can be a Boolean setup answering yes or no, true or false.
The tools involved throughout the lab are Reclassify, Euclidean Distance, Slope, Buffer, Cost Distance, Cost Path, and Weighted Overlay. At times it was necessary to get results through an assortment of other tools because with GIS there are options. If I cannot figure out a way I consult help which oftentimes mentions other tools to achieve the same results.
No comments:
Post a Comment