Hop farming suitability model

The hop growing study that Kenex created for the Ngati Hikairo iwi is a successful example of how smart GIS analysis can unlock land potential even with a high-level analysis conducted with national-scale freely available spatial data. 

The study translated industry requirements to GIS parameters and combined them to select land parcels that have all the right conditions for growing hops. The results of this model were used by the iwi to identify and prioritise new land parcels for acquisition as well as enhance the economic potential of existing and underutilised land.

The model

Ngati Hikairo’s rohe extents from the Kawhia Harbour to the town of Ohaupo and State Highway 3 and includes more than 2,800 land parcels. The entire rohe was investigated as the study area for this project. 

The main parameters used for this model were land cover, land capability, and slope, as the best conditions for hop growing are arable healthy grassland in flat areas. To refine and rank the suitable areas, Kenex also included wind speed and shelter, proximity to road and water features, proximity to irrigation and already existing farming operations in the model. 

The model identified all suitable areas for hop growing based on the main three parameters and then refined the results using the additional parameters. The land parcels selected by the modelling process were then ranked based on two further variables: the number of suitable hectares inside each parcel and the percentage of suitable area compared to the total area of the parcel. 

Results

The results show that only 117 of more than 2,800 parcels in the rohe meet the requirements for commercial hops growing. Of these parcels only one has the maximum rank (9), 9 parcels have the second highest rank, and 58 more parcels have very high ranks (5 to 7) for a total of more than 3,000 ha of potential land for growing hops.