Wind & Evaporation Breaks
While Central Texas receives approximately 32" per year of rainfall, our evaporation rate is the 48" or greater range. That evaporation rate is likely to increase with climate change. What Transeau's chart demonstrates is that different regions of the US have different ecosystems and functions based on the ratio of rainfall to evaporation rate. Thus, if you are below 60% of rainfall to evaporation, you are in a dry-land climate. At 60-80%, you are in the breadbasket region, and at > 100%, you are likely in a forest region.
In order to reduce evaporation, we need to reduce the carrying capacity of the wind. Windbreaks are an excellent tool, as well as mulch at 4" depth, to reducing the soil moisture losses to evaporation.