Gaining Spatial Insights with Latest SuperGIS Spatial Analyst
The updated version of SuperGIS Desktop was just released in November of 2016. In this update, Supergeo also released a new version of Spatial Analyst. Spatial Analyst is the extension helps users to integrate raster and vector data for analyzing complex spatial relationships. In this latest version, Spatial Analyst is augmented with several new zonal statistical features such as Tabulate Area and Zonal Histogram, assisting users to understand the pattern of particular phenomena. In this article, we would like to introduce what’s new in Spatial Analyst 10.
Tabulate Area enables users to compare the relationship between two raster data and then organize the result as a cross table. By applying Tabulate Area, users can illustrate the distribution of different values within a particular zone. For example, to achieve sustainable land use, the authority must examine whether a construction project follows the principles of disaster prevention and the purpose of land use. The Tabulate Area function is very suitable for viewing the relationship between different variables. Users can input land use data as a zone layer and slope data as a class layer into this tool. The result will show the slope area of different types within each land use categories.
Fig.1 A result of Tabulate Area shows the distribution of slopes and residential districts in Taipei, Taiwan.
Zonal Histogram examines the relationship between two raster layers with the values of the value raster layer. Users will obtain a histogram that records the data distribution of particular value. For example, you can apply land use data as class data and slope data as value data. After analyzing, users will get a table and a histogram showed the slope distribution in each zone.
Fig.2 The histogram shows the distribution of slopes in each residential area. From the histogram, we can know most area classified as r4 locate in the area which slope degree is from 0 to 7.5.
When we want to build a pavilion that has the broadest view, it is necessary to know the visible extent of each possible sites. After we know such information, the plan can be conducted more properly and meet the need as much as possible.
In SuperGIS Spatial Analyst 10, Supergeo adds more parameters in Surface Viewshed, including Observer elevation, Observer offset, Azimuth angles, etc. With these parameters, the analyzing result would become more realistic.
Fig.3 The figure shows the difference of result between previous and updated viewshed analysis. Left side: The result of the previous version can only set the surface and point of view. Right side: The result of updated version uses 50 as the value in observer offset. Therefore, the visible area will be wider than the left side.
Besides, SuperGIS Spatial Analyst improves some existing functions. In this version, Reclassify can save the parameters for reclassifying and also import external tables as parameters. Extract by Point and Extract by Circle are also supported in this version. Thus users can extract data with more choices. Also, the result of some functions now includes raster table, making data easier to display than before.
A Quick Summary
This featured article introduced what’s new in SuperGIS Spatial Analyst 10, including how to utilize Tabulate Area to compare the value and get a cross table to know the relationship between two variables. Furthermore, with the newly-added functions and flexible options in SuperGIS Spatial Analyst 10, users can run Spatial Analyst to solve issues with deeper geographic insights..