Visualize year-to-year variability in winter wheat yields over the past three decades and its relationship to variability in climate.
Increases in yield are apparent across the Columbia basin due to advances in technology (management, varietals). To more clearly see the effects climate variability on yield, we remove the long-term yield trend indicated by the red line in the upper graph. Differences between annual yield and the trend line are shown in the lower graph where green bars indicate above-normal and orange bars indicate below-normal yields.
The variability in wheat yields can be visualized as a function of late spring (Apr-Jun) precipitation and temperature. The figure below shows each year as a bubble according to the precipitation and temperature observed during that year, with the bubble colored according to if the yield was above-normal (top 33%), normal (middle 33%), or below-normal (bottom 33%). You can add/remove all the bubbles of each yield category by clicking on the name in the legend.
Projections of future climate variability over this county can be visualized by looking at a scatterplot of projections for late spring (Apr-Jun) precipitation and temperature from 20 global climate models for all years within a 30-yr future time period. Climate projections were bias corrected to local scales to facilitate use. The different models simulate climate differently leading to a spread of projections for each time period.
In the above figure, you can see that average Spring temperatures are generally projected to increase over the 21st century, while Spring precipitation is generally projected to stay the same.