By using Geographic Information Systems, we were able to map out soil capability and climate projections for the Okanagan region. Figure 2 shows the agricultural land reserve areas within the boundaries of the Okanagan, which covers 2085km2, 4.5% of the total ALR land in British Columbia.
Figure 2: A map representing the ALR areas in the Okanagan region of BC
Table 2, a table compiling data on the 7 soil capability classes with their characteristics, suitable crops and limitations. (Environment Canada, 1972) & (Roussin, 2014):
In the table shown above (table 2), is a compilation of data on the 7 soil classes with the characteristics associated and their limitations, which determines the crop types that are best suited. Limitations such as climate, topography, erosion, water-holding capacity and stoniness are common in the soil classes and increase in severity as you move towards class 7. These limitations and their severity can be applied to management strategies such as irrigation to improve the water-holding capacity.
Figure 3 shows a map of the Okanagan region which has been classified into soil capability of the land. The Okanagan region does not boast a lot of high quality arable land; it contains only 4.5% of the ALR land in BC (2085 km 2). Of this area, there is 249 km 2 that has high quality soil (classifications 1, 2, or 3) as defined by the Provincial Agricultural Land Comission.
Figure 3: Map of the Okanagan region in BC showing the agricultural soil capability, as assessed by the Provincial Agricultural Land Commission
The following three figures map the climatic conditions of frost free days, growing degree days and mean annual precipitation for the Okanagan region. Starting with the current climatic conditions, and then the predicted changes for 2025 and 2055. All three climatic conditions are predicted to increase in the future with the effects of climate change, extending the growing season available for agriculture. Though there is predicted increase in precipitation, water demand measures should still be planned for the future to support agricultural demand.
Figure 4: Map showing the predicted increase in annual frost free days in the Okanagan region, for the current climate, 2025 and 2055.
Figure 5: A map showing the predicted increase in annual growing degree days above 5 degrees celsius in the Okanagan region, for the current climate, 2025 and 2055.
Figure 6: A map showing the predicted increase in mean annual precipitation in the Okanagan region, for the current climate, 2025 and 2055.
Figure 7 shows the areas suitable for grape growing in the Okanagan region in 2055, based on growing degree days and frost free days. A literature review showed the optimum conditions required for grape growth (Association of BC Grape Growers and Agriculture Canada, 1989) and the only limiting factor that really affects grape growth currently is climate. Improved temperature and extended growing season will reduce limitations on grape productivity in the Okanagan region, though precipitation is increasing, irrigation management schemes should be put in place.
Figure 7: A map showing the optimum areas, in 2055, for growing grapes in the Okanagan region, based on growing degree days and frost free days.
Table 3 shows the results of the zonal statistics carried out on the climate change predictions for 2055. The predicted change in mean annual precipitation by 2055 was an increase of 1,054 mm and the mean ALR was within a region of 610 mm. Excellent grape growing conditions are between 90 and 2,720 mm depending on the variety of grape. The predicted increase of annual growing degree days by 2055 is 940 and the mean ALR was located in 2,011, where grapes grow best with annual growing degree days greater than 1,390. Annual frost free days are also predicted to increase by 2055 by 31 days with the mean ALR in 210 days. Excellent grape growing conditions lie within regions with more than 170 frost free days.
The output, mean ALR areas, are within an acceptable range for grape growing showing that the changing climactic conditions are not likely to cause a loss of agricultural land, used for the purposes of grape growing and other tree fruits. This implies that different crops may need to be planted to account for minor changes yet the ALR land will continue to support food security in the Okanagan at least until 2055, given the predicted changes.
Table 3: Zonal statistics of predicted changes in climatic conditions by 2055, compared to the optimum conditions required for grape growing.
