T he final Wine Grape Growing suitability map is a function of all of the three suitability analysis done in this study. The solar radiation suitability map and the degree day suitability map were produced from the grid files and they were in raster format. The soil suitability analysis however, was done by using vector data and therefore was converted to grid format using the "Feature to Raster" command of the Spatial Analyst. The value of the pixels in the grids where then unified to take only values one to four, 1 being the most unsuitable and 4 being the most suitable in each map. This was done using the reclassify command of the Spatial Analyst. The final map was then generated by multiplying the solar radiation suitability map by 2 and adding the result to the values of the soil suitability grid and the degree days suitability grid.

The result of raster calculation then had values ranging from 4 to 16. A final reclassification was also done to classify the results to 4 distinct classes.

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As can be seen from the map, the inner areas inside the Napa Valley seem to be in more suitable classes than other areas; which is what was expected because most of the vineyards are located inside the valley. The other characteristic of the map that can be verified is the fact that elevations have lower ranking in general this is also expected since high elevations are not suitable for growing vines as temperature is very low.

Conclusion
As can be seen from the map there are many areas in Napa that are suitable for wine growing, However this map takes into account only a few factors that can affect the grape production process. The scope of this study does not cover all the suitability factors and it's only meant to provide a general overview of Napa's Terroir.