create uniform areas that are >4500<5000m^2
separate raster data into bands in Arc Map
compute NDVI in Arc Map
create random samples in the areas in ArcMap
collect numerical data
save numerical data in .csv format
import .csv into R Studio
Use procedural flowchart to select a test
test assumptions of that test
test normality of data and homogeneity of variance
run tests to either a. reject the null hypothesis and b. accept the the alternate hypothesis.
R outputs (below) show some of the process of the statistical analysis. On the left, is one of the 6 theoretical quantile plots I used to visually assess the data. This one is the assessment of the normality of the data from an average of NDVI points from the acequia study areas in the sample part called pixel 1. I sampled each site 3 times, the data sets were named pixel 1, pixel 2, pixel 3. While there are probably better way top sample in NDVI. I used the Pixel Inspector tool that gives the value of pixels in a tabular data frame. I simple entered the first three columns of point (pix 1,2,and 3 in the code) into a csv file, for n=10 sites. In total I had 900 points, n=10(30x3). The points were then averaged. For this analysis I used the type of irrigation (acequia, and center point) as my predictor or independent variable and the NDVI value (a continuous numerical value from 1, to -1) as the response or dependent variable.
Results of the Shapiro Wilkes tests and Fligner tests showed that all of the data was normally distributed with significant p value >0.05. In addition, Fligner tests showed that all of the variances in the data sets were homogeneous. I then conducted a two sample t test.