Geologic and geomorphologic features applied for identification of wine terroir units by digital image processing, spectroradiometric and GIS techniques in Encruzilhada do Sul, RS, Brazil

Results in the characterization of a new wine terroir unit in south Brazil are reported. Presently, several areas in Brazil are being studied, in an effort to define new wine terroirs and improve the quality of Brazilian wines. This paper reports what is being done, by Embrapa (Brazilian Agricultural Research Corporation) and its partners Remote Sensing and Meteorological Research Center (CEPSRM/UFRGS) and Brazilian Geological Survey (CPRM), in the Encruzilhada do Sul region, at Rio Grande do Sul State, that is part of the Serra do Sudeste viticultural region. Satellite images from several sources (SRTM, ASTER, ALOS) were used, together with field data (rock samples). Digital elevation models were built and used to define areas with slopes and solar expositions adequate to vine growing, with altitudes above 350 m. Spectroradiometry of rock samples was performed, to identify several minerals (montmorilonite, illite, pyrophilite and kaolinite). Geologic maps were used to locate rock types to collected in field trips; those rocks had their spectral response extracted from radiometry, and fitted to the six bands of ASTER SWIR subsystem, resulting in a map of the distribution of these rocks in some areas of interest. Two wineries were more closely studied. The first area produces wine from 35 hectares of Cabernet Sauvignon, Merlot, Nebbiolo, Pinot Noir and Chardonnay. The other winery has 61 hectares and produces Pinot Noir and Chardonnay grapes for sparkling wines. The study concludes that the use of remote sensing resources and associated geotechnologies are effective to terroir studies.