Evidence of the drought conditions are all around us. A few that I've noticed just today: orchards being irrigated in January; a rainfed wheat crop planted in October that still hasn't germinated; another wheat crop that's been at the 2-leaf stage for almost 2 weeks and is starting to show signs of severe moisture stress. It's hard to miss the biological consequences of California's driest year on record at the field level. I was curious to see a quantification at the regional level. Here are a few snapshots that I dug up:

The below image is a satellite-produced NDVI (Normalized Difference Vegetation Index--the "greenness" is a proxy for plant growth) image of a portion of the Sacramento Valley on October 15th, 2011.  From 8/1/2011 to 10/15/2011 there had been 1.1 inches of rain recorded at the Colusa CIMIS station.

The next image is the NDVI of the same region on 10/15/2013. Only 0.5 inches of rain had been recorded between 8/1/2013 and 10/15/2013 at the Colusa CIMIS station at that point (and none since).

Here are a couple other visualizations of these same dry conditions relative to what is considered normal.

http://droughtmonitor.unl.edu/data/jpg/20131231/20131231_CA_trd.jpg

http://seca.unl.edu/web_archive/VegDRI/archive/131230/pdfs/all_CA_quad1_131230.pdf

One upshot that is likely to occur in the coming season is an increase in the use of groundwater for irrigation. This comes on the heels of deductions from groundwater stores that are higher than the rate of recharge over the past two years, as depicted here:

Individual growers and land managers will respond to the scarce water conditions according to their particular circumstances. This may include fallowing fields, digging deeper wells, or trying to improve the precision of irrigation applications. There are an increasing number of tools available to help implement that latter approach. One recent development based on work at UC-Davis is being brought to the market by Tule Technologies.  I'm hoping to work with this technology in the coming field season and would welcome the participation of interested collaborators!