Relocating White Rock VineyardsNapa County, California

Maya Ellington and Kavya Niranjan, GEOG C188 Fall 2017 Final Project

IntroductionWhite Rock Vineyards is one of the many small, family-run wine estates that was subjected to the terrible Napa Fires two months ago. They have been forced to permanently close as a result. While their underground cave cellars protected much of their valuable bottles of Napa wine, the Vandendriessche family is looking for new vineyard locations in Napa County, California to invest in. We compiled a list of opportunities and constraints we deemed most important for vineyard site selection, and that data was available for.

All of our analyses were performed using theProjected Coordinate System:NAD 1983 StatePlane California II FIPS 0402 FeetProjection: Lambert Conformal Conic

Sources:1. Napa County GIS Data Catalog2. SF Bay Region Built Network from Dr. Radke3. USGS 1/3 - arc DEM, clipped to Napa County (link)4. Marin County Parcel Points5. California Lakes from CA Dept. of Fish and Wildlife 6. Vineyard Site Selection, Eric Stafne

www.whiterockvineyards.com

We chose to avoid areas with high fire severity, as well as urban zone, water bodies, and existing agriculture as these would not be suitable locations for development. We also wanted to use potential prime cropland as a way to account for soil quality in vineyard site selection.

California wine grapes have very specific temperature and sun needs, and so are usually grown on gentle slopes and southern aspects. So we ran the Slope and Aspect Tools on a DEM that was clipped to the Napa County boundary in order to find suitable areas. The raster was converted to a shapefile before unioning to create Final Suitability

#1 Raster SuitabilityNapa County and its vineyards are popular tourist locations, and many people travel there from other parts of the country. So we chose to incorporate distance from bed and breakfasts as an opportunity. In the case of future fires, proximity to police and fire stations would also be important and hence were included in the network analysis.

#2 Initial Suitability #3 Network Suitability Final Suitability

Scalability Limits:This analysis is specific to California grapes and climate. Scaling this up would require creating a broader range of aspect and slope constraints, which would reduce specificity and introduce more error. It is also hard to know exactly where guests are traveling from, and travel times to Napa County are most likely seasonal. Another source of error is when we converted the resulting polygons to points using the Feature to Point Tool, as this just a simplification used to facilitate location-allocation.

After obtaining a Final Suitability Map, we wanted to present a few practical options to our client. First we selected four of the most ideal locations based on the suitability index and as well as the total area as specified by the client. The client also wanted to know which of the four locations was most accessible to Marin County, from where many of their patrons travel. The location we deemed most suitable is circled in red in the map below.

Final Network Analysis

After dissolving, we selected by the following attributes:● Suitability Index (“totalweight” field) greater than

25.After “exploding” each of these multi-part features, we added an “acres” field, and then selected all polygons with the following query:● “Acres” >= 14 AND “Acres” < 16This resulted in four polygons, shown as green squares on the map. We used Location-Allocation Network Analysis on these four Facilities to find which had the “Maximum Attendance” from Marin County parcel points. Despite specifying that we wanted the analysis to find 3 locations, the program informed us that a third location would not have improved attendance, and of the two resulting locations, the one circled on the map serviced the most number of demand points.

The Final Suitability Map was created by unioning the previous three shapefiles, and was used as an input in the Final Network Analysis, described below.