Anthropogenic aerosols mask increases in US rainfall by greenhouse gases

Nature Portfolio (Springer Nature) | February 22nd, 2024

Anticipating drought-related food security changes

Nature Portfolio (Springer Nature) | September 29th, 2022

Food insecurity early warning can provide time to mitigate unfolding crises; however, drought remains a large source of uncertainty. The challenge is to filter unclear or

Food insecurity early warning can provide time to mitigate unfolding crises; however, drought remains a large source of uncertainty. The challenge is to filter unclear or conflicting signals from various climatic and socio-economic variables and link them to food security outcomes. Integrating lag-1 autocorrelation diagnostics into remotely sensed observations from the Soil Moisture Active Passive (SMAP) mission and food prices, we found dramatic improvement in anticipating the timing and intensity of food crises, except in conflict settings. We analysed drought-induced food crises globally in the SMAP record (since 2015; approximately five per year). The change in soil moisture autocorrelation, which we term the Soil Moisture Auto-Regressive Threshold (SMART), signalled an accurate food security transition for all cases studied here (P 

Anticipating Environmental and Environmental-Health Implications of Extreme Storms: ARkStorm Scenario

American Society of Civil Engineers (ASCE) | July 22nd, 2015

The ARkStorm Scenario predicts that a prolonged winter storm event across California would cause extreme precipitation, flooding, winds, physical damages, and e

The ARkStorm Scenario predicts that a prolonged winter storm event across California would cause extreme precipitation, flooding, winds, physical damages, and economic impacts. This study uses a literature review and geographic information system-based analysis of national and state databases to infer how and where ARkStorm could cause environmental damages, release contamination from diverse natural and anthropogenic sources, affect ecosystem and human health, and cause economic impacts from environmental-remediation, liability, and health care costs. Examples of plausible ARkStorm environmental and health concerns include complex mixtures of contaminants such as petroleum, mercury, asbestos, persistent organic pollutants, molds, and pathogens; adverse physical and contamination impacts on riverine and coastal marine ecosystems; and increased incidences of mold-related health concerns, some vector-borne diseases, and valley fever. Coastal cities, the San Francisco Bay area, the Sacramento-San Joaquin River Delta, parts of the Central Valley, and some mountainous areas would likely be most affected. This type of screening analysis, coupled with follow-up local assessments, can help stakeholders in California and disaster-prone areas elsewhere better plan for, mitigate, and respond to future environmental disasters.

Anticipating responses to climate change and planning for resilience in California’s freshwater ecosystems

National Academy of Sciences (NAS) | July 29th, 2024

Application of Hydrologic Simulation Program—FORTRAN (HSPF) as Part of an Integrated Hydrologic Model for the Salinas Valley, California

U.S. Geological Survey (USGS) | April 8th, 2025

The U.S. Geological Survey (USGS), in cooperation with the Monterey County Water Resources Agency, conducted studies to help evaluate the surface-water and grou

The U.S. Geological Survey (USGS), in cooperation with the Monterey County Water Resources Agency, conducted studies to help evaluate the surface-water and groundwater resources of the Salinas Valley study area, consisting of the entire Salinas River watershed and several smaller, adjacent coastal watersheds draining into Monterey Bay. The Salinas Valley study area is a highly productive agricultural region that depends on the coordinated use of surface water and groundwater to meet demand for irrigation and public water supply. To continue to meet these demands, a better understanding of the historical water balance and the effects of water-resource development on the long-term sustainability of water resources in the Salinas Valley study area is needed.

Application of synthetic scenarios to address water resource concerns: A management-guided case study from the Upper Colorado River Basin

Climate Services (Elsevier) | December 9th, 2017

Water managers are increasingly interested in better understanding and planning for projected resource impacts from climate change. In this management-guided study, we u

Water managers are increasingly interested in better understanding and planning for projected resource impacts from climate change. In this management-guided study, we use a very large suite of synthetic climate scenarios in a statistical modeling framework to simultaneously evaluate how (1) average temperature and precipitation changes, (2) initial basin conditions, and (3) temporal characteristics of the input climate data influence water year flow in the Upper Colorado River. The results here suggest that existing studies may underestimate the degree of uncertainty in future streamflow, particularly under moderate temperature and precipitation changes. However, we also find that the relative severity of future flow projections within a given climate scenario can be estimated with simple metrics that characterize the input climate data and basin conditions. These results suggest that simple testing, like the analyses presented in this paper, may be helpful in understanding differences between existing studies or in identifying specific conditions for physically based mechanistic modeling. Both options could reduce overall cost and improve the efficiency of conducting climate change impacts studies.

Applying the Connectivity Approach: Groundwater management in California's Kings Basin

California Roundtable on Water and Food Supply (CRWFS) | March 27th, 2015

The California Roundtable on Water and Food Supply (CRWFS) studied the processes used in the Kings Groundwater Subbasin (Kings Basin) of California’s San Joaquin Valley

The California Roundtable on Water and Food Supply (CRWFS) studied the processes used in the Kings Groundwater Subbasin (Kings Basin) of California’s San Joaquin Valley to reveal strategies for advancing groundwater sustainability within the context of watershed-scale, integrated water management. This inquiry was guided by the principles of the “connectivity approach”: a framework developed by CRWFS for resource managers, land use planners and policymakers to discover the linkages, strengths, successes, potentials, and disconnects related to their particular resource stewardship issues. A key concept is connected benefits, which refers to achieving multiple benefits across resource and development sectors to respond to California’s increasing water management challenges.

Approaches for groundwater management in times of depletion and regulatory change

University of California, Davis (UC Davis) | June 1st, 2018

New legislation and related regulations in California mandate groundwater management to avoid undesirable results from excessive groundwater pumping and other hum

New legislation and related regulations in California mandate groundwater management to avoid undesirable results from excessive groundwater pumping and other human activities. Required aspects of management planning that will occur in well over 100 alluvial groundwater sub-basins across the state include scientific foundation and public transparency. While the details of individual groundwater management approaches will be particular to conditions in each management area, there will be common elements based on similar aspects of many groundwater systems in the state. The process of beginning to implement groundwater management for a large part of the state poses challenges. Use of scientific knowledge and methods of analysis developed in academia and industry will be helpful to the overall effort. This dissertation considers aspects of groundwater management that are expected to be common among many planning efforts. Inactive water supply wells acting as conduits for contaminant migration is considered through field examples and use of recently available databases regarding existing well constructions and water quality. Nonpoint source pollution effects on groundwater quality from conduit wells are investigated and selective regulatory action is explored as an option for addressing an issue that is too large for complete solution with available resources. Options for managed aquifer recharge are explored for a combined urban-agricultural area through use of a recently released land use database. A hydro-economic analysis is performed using linear programming to evaluate the efficacy of an on-farm recharge approach. Future work may include development of additional insights within the context of the study areas presented as well as extensions that consider new geographic areas and additional related considerations.

Approaches to Planning Water Resources

University of California, Davis (UC Davis) | July 15th, 2008

This paper attempts to summarize and organize various technical  approaches often seen or discussed for water resources planning. The basic approach to rational planning

This paper attempts to summarize and organize various technical  approaches often seen or discussed for water resources planning. The basic approach to rational planning is presented, followed by brief reviews of Requirements-based, Benefit-Cost-based, Multi-objective, Conflict Resolution, Market-based, and Muddling Through approaches to planning. Each approach has particular advantages and disadvantages for specific situations. Each approach also tends to have somewhat different analytical requirements. These approaches are discussed in terms of practical contributions to solving long-term water problems in contemporary contexts.

Aquifer depletion exacerbates agricultural drought losses in the US High Plains

Nature Portfolio (Springer Nature) | January 15th, 2024

Aquifer depletion poses a major threat to the ability of farmers, food supply chains and rural economies globally to use groundwater as a means of adapting to climate var

Aquifer depletion poses a major threat to the ability of farmers, food supply chains and rural economies globally to use groundwater as a means of adapting to climate variability and change. Empirical research has demonstrated the large differences in drought risk exposure that exist between rainfed and irrigated croplands, but previous work commonly assumes water supply for the latter is unconstrained. Here we evaluate how aquifer depletion affects the resilience of irrigated crop production to drought risk using over 30 years of data on historical corn and soybean yields, production areas and aquifer conditions for the High Plains region in the United States. We show that aquifer depletion reduces the ability of farmers to sustain irrigated crop yields and production areas in years and locations with large growing-season water deficits. Our findings demonstrate that drought-related production losses on irrigated croplands increase non-linearly with aquifer depletion, highlighting the need for proactive aquifer conservation interventions to support adaptation and resilience to future increases in rainfall variability under climate change.