Analysing the climate variability in the wine regions of New Zealand and Chile: A GIS perspective

Abstract

New Zealand and Chile being among the well-known "New World" wine producing countries, arguably have much in common as far as viticulture and wine production are concerned especially, in terms of rapid progress achieved in grapevine cultivation and wine produced over the last few years. The two countries are in the same hemisphere, and temperature latitudes but situated on either side of the prime meridian. In this context, the paper looks at some of the specific viticulture related aspects in different modalities, such as vector (point, contour), raster and text formats and then investigates into analysing the multimodal data collectively at a regional scale which is considered as appropriate for such a comparative study in this specific domain. The commonly used major themes for modelling viticulture and wine production until to date have been; growing degree days (GDD), minimum/ maximum temperatures during berry ripening, frost days at budburst for the wine regions within a country or in the world, and are briefly outlined. Meanwhile, at a relatively recent meso / micro scale (precision viticulture) modelling using grapevine vegetative growth and grape yield requires expensive equipment for multispectral satellite/ aerial borne imagery and yield data acquisition. Following a brief outline on the use of contemporary technologies, such as GPS, and methodologies to analyse information integrated into GIS, the paper then elaborates on the results of a comparative study conducted on seven major wine regions of New Zealand and Chile using GIS based thematic mappings of terrain, topography, climatic conditions, grapevine varieties as well as wine quality, the latter represented by regional vintage ratings, sommelier comments and wine label ratings. The results of one-way ANOVA tests show the difference across viticulture climate regimes of the seven regions as significant (95% confident). However, between countries the difference is significant only for dew point in November and December, sea level pleasure in December, and total precipitation in December.