Drought in California's Central Valley. NASA image created by Jesse Allen, Earth Observatory, using data provided by Inbal Reshef, Global Agricultural Monitoring Project. Caption by Holli Riebeek and Rebecca Lindsey. Instrument: Terra - MODIS

By the end of July 2009, California was well into its third dry year in a row. On average, the state’s reservoirs were running low. In particular, the San Luis reservoir had reached only 18 percent of its capacity by July 28, said the Drought Operations Center for the State of California. The San Luis Reservoir stores water from the Sacramento and San Joaquin River Delta to be distributed through the southern Central Valley. As water levels at the reservoir and elsewhere dropped, many water districts faced restrictions. The impact of those water restrictions on farms in the Westlands and Tulare Lake Districts is illustrated in this vegetation anomaly image. The image was made from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite between July 12 and July 27, 2009. The sensor records the amount of light that photosynthesizing plants absorb and reflect as they grow. The image shows how vegetation fared in 2009 compared to the average conditions from 2000 and 2008. In places where plants were growing more than average, the land is green. Cream shows areas of average growth, and brown points to less plant growth than average. In this image, dark squares of brown are scattered across much of the Westlands and Tulare Lake water districts. These brown squares are fields that would ordinarily support irrigated crops, but in 2009 the crops were not growing well or the fields lay fallow. …

Drought in California’s Central Valley