Ancient tree rings show Fresno, CA region’s drought history
The San Joaquin River watershed is amid its third consecutive year of below-normal precipitation. But three dry years are merely a drop in the bucket (pardon the pun) compared to a historical record that, thanks to climate reconstructions using tree rings, stretches back more than 1,100 years in the region. Scientists estimate that since the year 900 – when California was inhabited only by Native American tribes and centuries before it became a land of agricultural bounty – the region now known as the central San Joaquin Valley has endured 35 periods of sustained drought lasting at least four years …