Viticultural zoning: A comparative study regarding the accuracy of different approaches in vineyards climate suitability assessment

The paper presents the results of a study regarding the mesoclimate suitability assessment of three Romania’s wine-growing centres (Urlati-Dealu Mare vineyard, Husi-Husi vineyard, Bucium-Iasi vineyard), by the Huglin’s heliothermal index and by a GIS based multicriteria method. The results are compared between the two types of analysis and with the macroclimate suitability map of Romania’s wine regions, expressed by Huglin’s heliothermal index spatial distribution. The research show that the values of Huglin’s heliothermal index in Romania’s wine regions varies between 2341.48 on the Danube Terraces from the southern limit of the country to lower than 1500 on the intra- mountainous wine region Transylvania. The prevailing climate class over the Romania’s wine regions is IH-1 that define temperate climate. According to the assessment on Romania’s macroclimate scale by Huglin’s heliothermal index, the three wine-growing centers are characterized by temperate climate (IH-1), that indicate the existence of climate conditions for grapes maturation to Cabernet Sauvignon variety. The assessment on mesoclimate scale by the GIS based multicriteria method reveals a wider variability of local climate than that resulted from macroclimate and mesoclimate analysis by Huglin’s heliothermal index, as follows: the climate of Urlati wine-growing center is suitable for quality red wines production; in Husi wine-growing centre only 16.95% from the area has climate suitable to produce red table wines; the climate of Bucium wine-growing centre is not suitable for red wine production. Comparison with the Romania’s vineyards wine production specialization confirms that the results of multicriteria GIS based evaluation reveal accurate the local climate suitability and demonstrate the need of the fine-scale assessment of vineyard climate in the viticultural zoning.