Hi All,
I have been doing some analysis of monitoring points to find clusters of high concentrations of pollutant values. I have been exploring the results of the local spatial statistics tools (Local Moran's I and Gi*). The results seem to contradict each other in places. For example, mapping out the results of the local Moran's I values shows that a monitoring point has a negative Moran's I value, which means that it is surrounded by dissimilar values (Figure 1-the numbers next to the points are the raw monitoring values and the point circled in red is the point in question). I also mapped out the Z Scores of the local Moran's I analysis to see which values were statistically significant (Figure 2). Lastly, when running the hot spot analysis (Gi*) on my data set, the point in question received a high positive Z Score which means it is a statistically significant cluster of high values (Figure 3). These results seem contradictory to me. Why would the point be a part of a statistically significant cluster of high values when it is surrounded by dissimilar values?
Thanks for any and all help!
-Phil