Completed Projects

Estimating soil nitrogen mineralization for fertilizer management

Due to high groundwater nitrate concentrations, California growers are facing increasing pressure to improve nitrogen use efficiency in crop production to reduce nitrate leaching. This project determined nitrogen mineralization rates in the field and lab and has the potential to increase nitrogen use efficiency in crop production, resulting in lower risks of nitrate leaching to groundwater.

Debris flow and debris basin management impacts on water quality

Debris flows in the mountains of southern California pose acute hazards to local populations and may have far reaching water quality effects. For this project, researchers monitored water and sediment discharge from waterways to quantify suspended sediment impacts. The results of this study are helping local management agencies enhance debris basin management.

Temperature influence on juvenile salmonid swimming performance

Pacific salmon populations in California have rapidly declined in the past century, in large part due to dams and water diversions that block critical habitat and increase water temperatures in remaining habitat. This project sheds light on the mechanistic underpinnings of salmonid declines in California, and provides valuable information to help inform management decisions and guide recovery plans.

Monitoring tree survival in street-side stormwater facilities

Street-side stormwater management facilities are increasingly common as cities try to find ways to increase local water recharge. These facilities are often planted with vegetation that includes ornamental trees. However, little is known about the survival, growth, and health of the trees. This study resulted in a standardized monitoring protocol for trees in stormwater management facilities that can be used by cities that are installing their own facilities.

The impact of Salton Sea water management on air quality

The Salton Sea, the largest lake in Southern California, provides critical wildlife habitat. Efforts to conserve and recycle agricultural and municipal water, along with water transfers, have decreased the amount of water flowing into the lake. As a result, water in shallow areas is receding, exposing the dry lakebed, or playa, underneath. This newly exposed playa releases dust, especially during the winter months. 

Improving forage crop water productivity through innovative irrigation management

Decreased and more variable water supplies are expected in California’s San Joaquin Valley in the future and are likely to hit the region’s forage production sector particularly hard. Improving crop water productivity through innovative irrigation management and drought-resilient tillage and residue management techniques will be increasingly imperative in this region. 

Metagenomic analysis of groundwater wells

California uses approximately 15 billion gallons of groundwater per day, more than any other state in the United States. Biofilms formed in groundwater wells pose two potentially serious hazards to the state’s drinking water. This project analyzed the biofilm metagenomes of several groundwater wells to look for enrichment of gene clusters that may adversely affect water drinkability or production. 

Assessing environmental justice impacts in Integrated Regional Water Management

Throughout California, the lack of safe and affordable water is an every day reality in many disadvantaged communities. The California Department of Water Resources funded seven pilot projects to develop models for improving participation and addressing the water needs of these communities. This study assessed how well these IRWM planning efforts address the needs of disadvantaged communities in California.

Aiding relief efforts during famine

Monitoring hydroclimate extremes helps decision-makers reduce famine in developing countries. Researchers at UC Santa Barbara, in collaboration with the US Geological Survey and the Famine Early Warning Systems Network, have been investigating and monitoring the physical and social variables affecting food security and growing practices.

Online irrigation and nitrogen management tools for vegetables

Cool season vegetable production requires significant inputs of water and nitrogen fertilizer to maximize yield and quality. The results of this project increased the capacity of CropManage, an online resource that uses weather, soil, and crop data to assist growers in using water and nitrogen fertilizer efficiently for producing cool season vegetables.

Quantifying methylmercury loads from California rice fields

Methylmercury is found in low or no oxygen environments and can be toxic to wildlife at low levels. The objectives of this study are to quantify methylmercury loads from rice fields and determine at what time of year loads are greatest. This research will provide critical data on the types of methylmercury loads we can expect from rice fields and when methylmercury loads may be of concern.

Analyzing irrigation efficiency

Spatial analysis of irrigation efficiencies is critical to implementing water conservation strategies as climate changes over time. This study utilizes spatial approaches to presenting and managing data on transpiration ratios, surface soil retention and evaporation rates, and local weather conditions.

Improving groundwater recharge

Improving aquifer storage recovery operations can help to reduce nutrient loads and increase water supplies. This analysis of managed aquifer recharge in central coastal California quantified variability in infiltration, recharge, groundwater movement, and water quality. 

Assessing water quality & conservation attitudes

Water supplies are critical to urban populations in southern California. These supplies and the associated ecosystems are impacted by residents' decisions with respect to water conservation, pollution prevention, and landscape plants. 

Balancing species, ecosystem, and water resource needs

In many California watersheds, farmers and conservationists are working side-by-side to conserve winter rainfall in off-channel ponds to enhance dry season habitat for salmon. However, stream flow targets to guide successful project implementation are lacking.

Minimizing hexavalent chromium

Chromium(VI), known as hexavalent chromium, is a highly toxic and soluble compound that has been widely observed in groundwater across California. A new drinking water standard specific to chromium(VI) was recently proposed by the California Department of Public Health.

Regulating social and environmental costs of hydraulic fracturing

While California shale presents an extensive resource and has the potential to provide substantial benefits, expanded development of unconventional oil and gas production could require dramatic changes in the quantity and quality of water available for other uses in California.

Water quality and alfalfa yield

The Sacramento-San Joaquin River Delta region is a unique agricultural region of California. Delta farming is challenged by soil salinity, which can stress crops and reduce yields.

Forest management, water yields, and ecosystem services

Water provision is an important ecosystem service, particularly in forest ecosystems like those of California's Sierra Nevada mountains. As the climate changes, the way water moves through forests is also changing, which impacts downstream users. This project is evaluating trade-offs between different types of forest management and their impacts on water provision.