Orunmbe's GIS Jaunt: Mod5 - Spatial Statistics

Spatial Statistics

This week lab assignment focused on Statistical analysis of Spatial data sets. The objectives of this lab assignment are:

Learn how to analyze web downloaded spatial data using the Spatial Statistical Toolbox and Geostatistical Analyst Extension, in calculating the mean, median, and generating the directional distribution, and trend analysis graph of the identical patterns in the given data.
I also learn how to use histogram, normal QQ plot, semivariogram cloud and voronoi map to find outliers in a data set.
Learn key statistical/mapping terms such as: Brushing, Linking etc.
Learn to visually analyze the data.

The Spatial statistics lab was completed using the data and instructions in ESRI's "Exploring Spatial Patterns in Your Data Using ArcGIS" training.

To complete this lab, I downloaded the data folder to my S: drive, install the executable file and ran the it. I then open the map in ArcMap, searched for Mean Center using the Search Tool in ArcMap. The Mean Center generate the average location of the data set. I followed the same process to determine the Median Center. As can be in the above map, the green dot and red pentagon represent the Mean Center and Median Center respectively.

In the spatial statistic tool under ArcTool box in ArcMap, I use the Ellipse tool to create the black-banded-yellow ellipse over the data set. This ellipse is the Directional Distribution of the data set. The data sets are east-west oriented.

I further explored the Geostatiscal Analyst tool and created a Voronoi map, semivariogram cloud, a histogram and normal QQ plot. The histogram, voronoi map and semivariogram cloud produce a visual detail of a normally distributed map that will aid me to identify the outliers in the data set.

This lab shows me that an entropy voronoi map display to local variation in the data set, the normal QQ plot display how closely the data sets display the characteristics of the data distribution are, while the histogram display the frequency of the data value.

Below are sample Histogram, Normal QQ plot, Moroni map, Semivariogram/Covariance Cloud and Trend analysis maps for the western and central Europe temperature analysis.