Drought impact on cropland use monitored with AVIRIS imagery in Central Valley, California

Science of the Total Environment (Elsevier) | November 19th, 2022

During 2012–2016 California experienced the longest and most severe drought in the last centuries. This water scarcity led to an increase in non-cultivated croplands du

During 2012–2016 California experienced the longest and most severe drought in the last centuries. This water scarcity led to an increase in non-cultivated croplands during this period. The objective of this study was to quantify agricultural trends in the Central Valley (California) at peak growth from 2013 to 2016 during the drought and in 2017–2018 post-drought. For this purpose, we analysed yearly official harvested area reported at county level for the main crops and compared them to visible-shortwave infrared (VSWIR) spectra acquired by the Airborne Visible/Infrared Imaging-Spectrometer (AVIRIS-classic) over 2334 km2 of the Central Valley each year. Multiple Endmember Spectral Mixture Analysis (MESMA) was applied to AVIRIS data to estimate green vegetation (GV), non-photosynthetic vegetation (NPV) and soil fractions in crop fields each year. MESMA and crop reports (R2 = 0.9) showed that soil (i.e.; non-cultivated areas) increased during the summers of the drought; with the smallest GV area in 2015, the second year classified with exceptional drought in this period. According to MESMA, 34 % of the cropland was covered by GV in 2015, and 69.5·104 ha according to the crop reports. MESMA also registered the highest value of soil area in 2015 (48 %). The year with most cultivated area was 2017, the wettest year in the studied period, with 54 % of the croplands covered by GV and 75.2·104 ha. This study verified that the non-cultivated areas increased in the Central Valley during the exceptional drought period and validated the use of AVIRIS imagery to monitor broad-scale cropland use changes in future climatic extreme events.

Drought impacts to water footprints and virtual water transfers of the Central Valley of California

American Geophysical Union (AGU) | June 23rd, 2017

Drought intensity and duration interact to magnify losses in primary productivity

American Association for the Advancement of Science (AAAS) | October 16th, 2025

As droughts become longer and more intense, impacts on terrestrial primary productivity are expected to increase progressively. Yet, some ecosystems appear to acclimate t

As droughts become longer and more intense, impacts on terrestrial primary productivity are expected to increase progressively. Yet, some ecosystems appear to acclimate to multiyear drought, with constant or diminishing reductions in productivity as drought duration increases. We quantified the combined effects of drought duration and intensity on aboveground productivity in 74 grasslands and shrublands distributed globally. Ecosystem acclimation with multiyear drought was observed overall, except when droughts were extreme (i.e., ≤1-in-100-year likelihood of occurrence). Productivity losses after four consecutive years of extreme drought increased by ~2.5-fold compared with those of the first year. These results portend a foundational shift in ecosystem behavior if drought duration and intensity increase, from maintenance of reduced functioning over time to progressive and profound losses of productivity when droughts are extreme.

Drought, agricultural adaptation, and sociopolitical collapse in the Maya Lowlands

National Academy of Sciences (NAS) | May 5th, 2015

Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800–9

Paleoclimate records indicate a series of severe droughts was associated with societal collapse of the Classic Maya during the Terminal Classic period (∼800–950 C.E.). Evidence for drought largely derives from the drier, less populated northern Maya Lowlands but does not explain more pronounced and earlier societal disruption in the relatively humid southern Maya Lowlands. Here we apply hydrogen and carbon isotope compositions of plant wax lipids in two lake sediment cores to assess changes in water availability and land use in both the northern and southern Maya lowlands. We show that relatively more intense drying occurred in the southern lowlands than in the northern lowlands during the Terminal Classic period, consistent with earlier and more persistent societal decline in the south. Our results also indicate a period of substantial drying in the southern Maya Lowlands from ∼200 C.E. to 500 C.E., during the Terminal Preclassic and Early Classic periods. Plant wax carbon isotope records indicate a decline in C4 plants in both lake catchments during the Early Classic period, interpreted to reflect a shift from extensive agriculture to intensive, water- conservative maize cultivation that was motivated by a drying climate. Our results imply that agricultural adaptations developed in response to earlier droughts were initially successful, but failed under the more severe droughts of the Terminal Classic period.

Early Reclamation and Abandonment of the Central Sacramento-San Joaquin Delta

Sacramento Historical Society | September 15th, 2006

Economic Analysis of the 2014 Drought for California Agriculture

University of California, Davis (UC Davis) | July 15th, 2014

California is enduring its third driest year on record as agricultural, urban and environmental demands for water are at an all-time high. This report presents an assessm

California is enduring its third driest year on record as agricultural, urban and environmental demands for water are at an all-time high. This report presents an assessment of the economic impacts of the 2014 drought on crop production, livestock and dairies using a suite of models.  This analysis extends the preliminary estimates of the Central Valley drought impacts released May 19, 2014 (Howitt et al. 2014) to include:  •Broadened coverage of the Statewide Agricultural Production Model (SWAP) to include majoragricultural areas on California's central and south coasts and inland farms of the Imperial,Coachella and Palo Verde valleys, •Updated SWAP agricultural production and economic impact estimates for the Central Valleyusing the most current data available, •Estimated Central Valley impacts if the drought persists through 2015 and 2016, includingeconomic effects and the impact of increasing groundwater depletion and pumping depths usingthe California Department of Water Resources’ (DWR) C2VSIM model, •Estimated fallowing of cropland due to drought using the SWAP model, •Estimated losses to dairies and livestock using a supply elasticity approach based on pasturelosses and feed crop prices, and •Comments on the preliminary draft from various state agencies. The study finds that the 2014 drought will result in a 6.6 million acre-foot reduction in surface water available to agriculture. This loss of surface water will be partially replaced by increasing groundwater pumping by 5 million acre-feet.  The resulting net water shortage of 1.6 million acre-feet will cause losses of $810 million in crop revenue and $203 million in dairy and other livestock value, plus additional groundwater pumping costs of $454 million. These direct costs to agriculture total $1.5 billion. The total statewide economic cost of the 2014 drought is $2.2 billion, with a total loss of 17,100 seasonal and part-time jobs. Table ES-1 summarizes the key findings of the study. 

Economic Analysis of the 2015 Drought for California Agriculture

University of California, Davis (UC Davis) | August 17th, 2015

In 2015 California agriculture is facing its fourth year of severe drought. As in 2014, irrigation districts and farmers are showing more resilience to the drough

In 2015 California agriculture is facing its fourth year of severe drought. As in 2014, irrigation districts and farmers are showing more resilience to the drought than many had anticipated. Groundwater substitution has again greatly reduced crop fallowing and job losses. Water trading and operational flexibility also have significantly reduced the costs of the drought, and preservation of the most valuable crops has helped buffer economic impacts. However, the effects of drought are unevenly distributed over regions. In some regions with limited groundwater reserves the economic and employment impacts are very severe. In others, there is an increased cost of expanded groundwater use which is partially offset by high crop prices. Just as the economic impacts of the drought have grown modestly since 2014, continuation of the drought to 2016 or beyond with similar intensity is likely to slowlyerode the state’s agricultural production and employment.

Economic Analysis of the 2016 California Drought on Agriculture

University of California, Davis (UC Davis) | August 15th, 2016

Persistent dry conditions over the past few years have put California’s irrigated agriculture under severe water stress. Improved precipitation during the win

Persistent dry conditions over the past few years have put California’s irrigated agriculture under severe water stress. Improved precipitation during the winter and spring of 2016, and favorable market conditions, among other factors, have improved prospects for agriculture in 2016. However, water supply restrictions for temperature, endangered species, and salinity management continue to challenge some farming regions. We present an analysis of the economic impact of the 2016 drought on California’s agriculture. The analysis relies on a suite of models and data to estimate responses to water scarcity. The Statewide Agricultural Production Model (SWAP, Howitt et al. 2012) is calibrated to average year water conditions and used to simulate the response of agriculture to changes in water availability. SWAP model output is linked to the IMPLAN input­output model and used to estimate changes in gross revenues, employment, and value added across all related sectors ofthe economy. The report is structured as follows. First, we summarize 2016 water supply conditions for agriculture. Next, we present the results of an economic analysis of impacts to agriculture using the SWAP model, and impacts to ancillary industries using the IMPLAN model. We conclude with a discussion of policy implications, limitations, and future analyses. Several appendices provide further details on groundwater availability and cost, land fallowing, consumptive use, livestock and dairies, employment, and regional economic impacts.

Economic and Environmental Implications of California Crop and Livestock, Adaptation to Climate Change

California Natural Resources Agency (CNRA) | August 27th, 2018

Economic Impacts of SGMA on San Joaquin Valley Dairies and Beef Cattle

Dairy Cares (California Cattle Council) | January 30th, 2023