# Satellite Monitoring of Italian Vineyards and Spatio-Temporal Variability Assessment
## 3 Results
### VIs Development  
The second subsection paid attention to the vineyard biomass accumulation monitored from S2 in the 60-day temporal window. Hence, the present section focused on the regression line's slope between VIs and DOY. Again, the mean and the CV of the regression line's slope were computed both for the NDVI and NDRE. Then, the statistical indices were compared with the structural and topographic features. The outputs mentioned above aimed to respond to the second research question. The overall VIs' mean slope and the slope's CV are displayed in Figures 13a and 13b, respectively. Such analyses explained 34.70% and 32.79% of the variance, respectively. Also, in the present section, mean and CV were split into two separate analyses, while  
Figure 11: The boxplots describe seasonal mean and CV computed per each VI through the six vintages according to the topography classes used in this paper. The boxplots (**a,b**) display the seasonal average VIs: (**a**) refers to NDVI, and (**b**) refers to NDRE. The boxplots (**c,d**) display the values of the seasonal CV: boxplot (**c**) refers to NDVI and boxplot (**d**) refers to NDRE. Figure 12: The boxplots describe seasonal mean and CV computed per each VI through the six vintages according to the training systems considered for this paper. The boxplots (**a,b**) display the seasonal average VIs: (**a**) refers to NDVI, and (**b**) refers to NDRE. The boxplots (**c,d**) display the values of the seasonal CV: boxplot (**c**) refers to NDVI and boxplot (**d**) refers to NDRE. NDV and NDRE were joined in the same plot. The graphical projection of the average slopes showed a different direction of the vectors compared to the plot in Figure 8a. In particular, the vectors of the VIs average slope had a direction opposite to the latitude. The vineyards' number of vertices, elevation, and row spacing were also drawn in the opposite half quadrant concerning the VIs' slopes. In plot b, a weak positive relationship was verified between the CV and latitude, orientation, and elevation. Table 6 lists the result of the ANOVA performed on the averaged slopes and the slopes' CV. First, vintage and training system always showed a relevant effect on all the variables, while only the CV was relevant for the vineyards' direction. [PERSON]'s test showed that the NS and SE orientations had higher CV than EW and SW. More in detail, the boxplots in Figure 14 present the direction clustering, in which NS reached the highest CV and EW the lowest both for the NDVI and NDRE (0.00184 and 0.00172, respectively, for NDVI and 0.00144 and 0.00132, respectively, for NDRE). As shown in Figure 15a, vineyards planted in a plain reached a higher regression line slope than those planted in a hilly landscape for NDVI and NDRE. A high regression line slope means a vineyard planted in a plain may increase the VI average value faster than one planted in a hilly landscape. Therefore, a large data variability was observed in the plain class; divergent average values were found between plain and hill for NDVI and NDRE (0.00134 and 0.00058, respectively, for NDVI and 0.00133 and 0.00066, respectively, for NDRE). Similar results are presented in Figure 15c,d, in which the vineyards planted on a flat terrain showed a higher VI daily increase than those planted on a sloped side. Also, in this case, large data variability was observed; the flat and the sloped classes retrieved divergent average values both for the NDVI and NDRE (0.00126 and 0.00025, respectively, for NDVI and 0.00122 and 0.00051 respectively, for NDRE). Finally, Figure 16 shows four boxplots referred to the training system; HS was the training system reaching the highest VI average daily increasing rate, while VS was the smallest (0.00339 and 0.00070, respectively, for NDVI and 0.00273 and 0.00083 respectively, for NDRE). On the contrary, VS was the most stable training system, retrieving lower CV than HS (0.00174 and 0.00198, respectively, for NDVI and 0.00135 and 0.00158, respectively, for NDRE).