Data-driven methods for the extraction, grouping and application of terroir units

Data-driven methods for the delineation of viticultural zones have become increasingly relevant, necessitated by the transition from subjective, expert-based methods to objective and transparent methods. The use of subjective expert knowledge to inform zone boundaries can lack empirical evidence, making the justification of zone boundaries challenging. Modern methods derive zone boundaries based on the analysis of factors of the natural environment (climate, terrain, and soil) that constitute terroir. The first experiment aimed to develop a method for the delineation of basic terroir units. A stepwise method was developed in which the multiresolution segmentation (MRS) and spectral difference segmentation (SDS) algorithms were used to segment slope and height above nearest drainage (HAND) into terroir representative minimum mapping units. These units were used as the foundation for the following set of experiments. The second set of experiments aimed to identify the most effective method for grouping the basic terroir units derived from the first experiment. Overall MRS outperformed SDS and both the k-means and hierarchical clustering. MRS produced the most spatially uniform and practical zones. Between the two clustering algorithms, hierarchical clustering produced less fragmented results than k-means, and higher Moran’s Index scores. Data-driven zoning can reduce expert subjectivity, providing empirical evidence to support decision-making for legislators and producers regarding geographic indication (GI) boundaries. The data-driven methods presented in this research provide new approaches to zoning by demonstrating the value of object-based image analysis (OBIA), finding it to be a highly effective alternative to pixel-based or vector overlay zoning methods. Further development of these methods could support viticultural zoning in South Africa, ensuring the sustainability of the Wine of Origin scheme in the context of a changing climate.

Grantor dc:publisher

Stellenbosch : Stellenbosch University

Year dc:date.issued

2026

Author dc:creator

• West, Jonathan Robert

Advisors dc:contributor.advisor

• Van Niekerk, Adriaan
• Southey, Tara

Language dc:language.iso

en

Repository record dc:identifier.uri

https://scholar.sun.ac.za/handle/10019.1/135558

OAI identifier oai:identifier

oai:scholar.sun.ac.za:10019.1/135558