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Nutrient Fluxes from Sediments in the San Francisco Bay Delta

Estuaries and Coasts (Springer) | January 1st, 2014

Summary

In September 2011 and March 2012, benthic nutrient fluxes were measured in the San Francisco Bay Delta, across a gradient from above the confluence of the Sacramento and

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Nutrient Management Strategy for San Francisco Bay

San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) | November 1st, 2012

Summary

This document presents a draft strategy for developing the science needed to make informed decisions about assessing nutrient impacts on water quality, protecting benefic

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Nutrient Management Strategy Science Plan Report

San Francisco Estuary Institute (SFEI) | September 9th, 2016

Summary

The San Francisco Bay (SFB) estuary receives large inputs of the nutrients nitrogen and phosphorous from anthropogenic sources, and has the potential to suffer negative

The San Francisco Bay (SFB) estuary receives large inputs of the nutrients nitrogen and phosphorous from anthropogenic sources, and has the potential to suffer negative impacts from nutrient overenrichment. Nutrient concentrations in SFB exceed those in other estuarine ecosystems where degradation is strongly expressed. To date, SFB has shown resistance to some of the classic symptoms of nutrient over-enrichment, such as excessive phytoplankton biomass as chlorophyll-a (chl-a) and low dissolved oxygen (DO). Recent observations, however, suggest that SFB’s resistance to nutrient enrichment is weakening, and have generated concern that SFB may be trending toward, or may already be experiencing, adverse impacts due to its high nutrient loads. In response to these concerns, the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) worked collaboratively with stakeholders to develop the San Francisco Bay Nutrient Management Strategy (NMS).1 The NMS lays out an overall approach for developing the underlying science to support nutrient management decisions. This report presents a Draft Science Plan for implementing the SFB NMS. The report’s main goals include: Lay out a multi-year Science Plan representing a logical sequence of studies to inform major management decisions, assuming a time-line of 10+ years. Develop an approach and rationale for sequencing and prioritizing among studies, and identify specific high-priority studies, in particular those that should proceed in FY2016- 2018. Provide realistic estimates of the time-frame and funding needed to support a Science Plan that will successfully inform management decisions. The Draft Science Plan was developed in 2014-15 with input from science advisors (Table 1.1), the NMS Steering Committee, and the NMS Nutrient Technical Work Group (Fig. 1.1). Projects are described in more detail in the first 1-3 years, and in increasingly less detail over time, recognizing that the Science Plan will be iteratively refined based on new insights gained as work progresses.

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Nutrient Management Strategy Science Program

San Francisco Estuary Institute (SFEI) | September 1st, 2017

Summary

San Francisco Bay (SFB) receives large inputs of the nutrients nitrogen (N) and phosphorous (P) from anthropogenic sources. N and P are essential components of a healthy

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Nutrients in the Nation’s Streams and Groundwater, 1992–2004

U.S. Geological Survey (USGS) | June 6th, 2011

Summary

This report is one of a series of publications, The Quality of Our Nation’s Waters, which describes major findings of the NAWQA Program on water-quality issues of regio

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Nutrients in the Nation’s Streams and Groundwater: National Findings and Implications

U.S. Geological Survey (USGS) | September 1st, 2010

Summary

A comprehensive national analysis of the distribution and trends of nutrient concentrations in streams and groundwater from 1992 through 2004 is provided by

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Oases of the future? Springs as potential hydrologic refugia in drying climates

Ecological Society of America (Wiley) | June 1st, 2020

Summary

Natural springs in water‐limited landscapes are biodiversity hotspots and keystone ecosystems that have a disproportionate influence on surrounding landscapes despite t

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Objective definition of rainfall intensity-duration thresholds for the initiation of post-fire debris flows in southern California

Landslides (Springer) | June 27th, 2012

Summary

Rainfall intensity–duration (ID) thresholds are commonly used to predict the temporal occurrence of debris flows and shallow landslides. Typically, thresholds are sub

Rainfall intensity–duration (ID) thresholds are commonly used to predict the temporal occurrence of debris flows and shallow landslides. Typically, thresholds are subjectively defined as the upper limit of peak rainstorm intensities that do not produce debris flows and landslides, or as the lower limit of peak rainstorm intensities that initiate debris flows and landslides. In addition, peak rainstorm intensities are often used to define thresholds, as data regarding the precise timing of debris flows and associated rainfall intensities are usually not available, and rainfall characteristics are often estimated from distant gauging locations. Here, we attempt to improve the performance of existing threshold-based predictions of post-fire debris-flow occurrence by utilizing data on the precise timing of debris flows relative to rainfall intensity, and develop an objective method to define the threshold intensities. We objectively defined the thresholds by maximizing the number of correct predictions of debris flow occurrence while minimizing the rate of both Type I (false positive) and Type II (false negative) errors. We identified that (1) there were statistically significant differences between peak storm and triggering intensities, (2) the objectively defined threshold model presents a better balance between predictive success, false alarms and failed alarms than previous subjectively defined thresholds, (3) thresholds based on measurements of rainfall intensity over shorter duration (≤60min) are better predictors of post-fire debris-flow initiation than longer duration thresholds, and (4) the objectively defined thresholds were exceeded prior to the recorded time of debris flow at frequencies similar to or better than subjective thresholds. Our findings highlight the need to better constrain the timing and processes of initiation of landslides and debris flows for future threshold studies. In addition, the methods used to define rainfall thresholds in this study represent a computationally simple means of deriving critical values for other studies of nonlinear phenomena characterized by thresholds.

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Observational evidence of increased afternoon rainfall downwind of irrigated areas

Nature Portfolio (Springer Nature) | April 10th, 2025

Summary

Irrigation plays a vital role in addressing the growing food demand of an increasing global population. It represents one of the most critical and direct human interventi

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Observational Study of Sycamore Regeneration at two sites in Santa Clara County after the 2016-2017 Water Year

San Francisco Estuary Institute (SFEI) | June 1st, 2018

Summary

This memo serves as an update to the Sycamore Alluvial Woodland Habitat Mapping and Regeneration Study (Beagle et al. 2017), and describes changes seen at the two study s

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Nutrient Fluxes from Sediments in the San Francisco Bay Delta

Nutrient Management Strategy for San Francisco Bay

Nutrient Management Strategy Science Plan Report

Nutrient Management Strategy Science Program

Nutrients in the Nation’s Streams and Groundwater, 1992–2004

Nutrients in the Nation’s Streams and Groundwater: National Findings and Implications

Oases of the future? Springs as potential hydrologic refugia in drying climates

Objective definition of rainfall intensity-duration thresholds for the initiation of post-fire debris flows in southern California

Observational evidence of increased afternoon rainfall downwind of irrigated areas

Observational Study of Sycamore Regeneration at two sites in Santa Clara County after the 2016-2017 Water Year

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