In this study, researchers conducted an inventory of El Bierzo district vineyards in Leon, Spain. In this region, known for its Godello and Mencía varietals, nearly 16 million liters of wine are produced annually by just over 4,000 wine growers. By using two Landsat images (one showing the region at growth maximum and the other close to harvest) instead of just one Landsat image, the researchers found that they could increase their inventory accuracy by 30 percent.
This research concluded that medium spatial-resolution Landsat data cannot be used to estimate the absolute value of vineyard area because the standard error is too large. However, their Landsat-based method can estimate relative vineyard area and see changes over time.
Current methods of inventorying vineyards require comprehensive field surveys which are time consuming and expensive. So, employing this Landsat-based inventory method to identify areas of change will aid field surveys by being able to focus them on only areas of change. Additionally, the authors expect that their methodology coupled with higher spatial-resolution data could lead to improved accuracy.
Rodíguez-Pérez, J.R., Álvarez López, C.J., Miranda, D., and Álvarez, M.F. (2008).Vineyard area estimation using medium spatial resolution satellite imagery.Spanish Journal of Agricultural Research, vol. 6, no. 3, pp 442–452.