MAPPING GEOLOGY, CLIMATE, AND VINEYARDS: YADKIN VALLEY AVA, NC
The research objective was to develop a Geographic Information System (GIS) to map the distribution of 28 Yadkin Valley AVA vineyards within the spatial context of elevation, slope, and aspect, mean annual precipitation, and mean annual temperature. Data sources included 3 meter (spatial resolution) bare-earth LiDAR digital elevation models (DEM) provided by the North Carolina Floodplain Mapping Program. These county-wide DEMs were used to construct derivative slope and aspect maps.
Vineyard elevations range from 740 to 1464 feet and correlate positively with slope. Site visits to four higher elevation (> 1160 ft.) vineyards suggest, however, that the slope variation may exceed that depicted within 20 ft. pixels, and that slope may affect soil type and drainage, both of which are essential to grape choice within a vineyard and productivity. Aspect, which determines the number of hours of sunlight that a vineyard will receive, may be more relevant at higher elevation. A correlation between aspect and elevation was not observed within our data at any elevation suggesting that aspect was not an important factor in vineyard site selection. Spatial variation within mapped macroscale climate variables, mean annual temperature (55 – 59 oF) and precipitation (45 – 51 inches), correlated most closely with elevation. Limited onsite visits suggest that individual vineyards may experience important mesoscale climate variation which is important for grape variety selection.
One of the primary benefits to the GIS is the ability to identify variables warranting further mapping and analysis such as grape variety variation with elevation and slope, or onsite research such as soil analysis with slope variation.