Characterizing Early 20th Century Outflow and Salinity Intrusion in the San Francisco Estuary

This work presents updated reconstructions of watershed runoff to San Francisco Estuary from tree-ring data to AD 903, coupled with models relating runoff to freshwater flow to the estuary and salinity intrusion. We characterize pre-development freshwater flow and salinity conditions in the estuary over the past millennium and compare this characterization with contemporary conditions to better understand the magnitude and seasonality of changes over this time. This work shows that the instrumented flow record spans the range of runoff patterns over the past millennium (averaged over 5, 10, 20 and 100 years), and thus serves as a reasonable basis for planning-level evaluations of historical hydrologic conditions in the estuary. Over annual timescales we show that, although median freshwater flow to the estuary has not changed significantly, it has been more variable over the past century compared to pre-development flow conditions. We further show that the contemporary period is generally associated with greater spring salinity intrusion and lesser summer–fall salinity intrusion relative to the pre-development period. Thus, salinity intrusion in summer and fall months was a common occurrence under pre-development conditions and has been moderated in the contemporary period due to the operations of upstream reservoirs, which were designed to hold winter and spring runoff for release in summer and fall. This work also confirms a dramatic decadal-scale hydrologic shift in the watershed from very wet to very dry conditions during the late 19th and early 20th centuries; while not unprecedented, these shifts have been seen only a few times in the past millennium. This shift resulted in an increase in salinity intrusion in the first three decades of the 20th century, as documented through early records. Population growth and extensive watershed modification during this period exacerbated this underlying hydrologic shift. Putting this shift in the context of other anthropogenic drivers is important in understanding the historical response of the estuary and in setting salinity targets for estuarine restoration. By characterizing the long-term behavior of San Francisco Estuary, this work supports decision-making in the State of California related to flow and salinity management for restoration of the estuarine ecosystem.

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Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century

Marine Geology ◽

10.1016/j.margeo.2013.04.007 ◽

2013 ◽

Vol 345 ◽

pp. 63-71 ◽

Cited By ~ 21

Author(s):

David H. Schoellhamer ◽

Scott A. Wright ◽

Judith Z. Drexler

Keyword(s):

20Th Century ◽

San Francisco ◽

San Francisco Estuary ◽

Sediment Supply

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Supporting Restoration Decisions through Integration of Tree-Ring and Modeling Data: Reconstructing Flow and Salinity in the San Francisco Estuary over the Past Millennium

10.20944/preprints202106.0122.v1 ◽

2021 ◽

Author(s):

Paul H Hutton ◽

David M Meko ◽

Sujoy B Roy

Keyword(s):

San Francisco ◽

Tree Ring ◽

San Francisco Estuary ◽

Salinity Intrusion ◽

Estuarine Ecosystem ◽

Freshwater Flow ◽

The Past ◽

Decadal Scale ◽

Tree Ring Data ◽

Past Millennium

This work presents updated reconstructions of watershed runoff to San Francisco Estuary from tree-ring data to AD 903, coupled with models relating runoff to freshwater flow to the estuary and salinity intrusion. We characterize pre-development freshwater flow and salinity conditions in the estuary over the past millennium and compare this characterization with contemporary conditions to better understand the magnitude and seasonality of changes over this time. This work shows that the instrumented flow record spans the range of runoff patterns over the past millennium (averaged over five, ten, twenty and one hundred years), and thus serves as a reasonable basis for planning-level evaluations of historical hydrologic conditions in the estuary. Over annual timescales we show that, although median freshwater flow to the estuary has not changed significantly, it has been more variable over the past century compared to pre-development flow conditions. We further show that the contemporary period is generally associated with greater spring salinity intrusion and lesser summer-fall salinity intrusion relative to the pre-development period. Thus, salinity intrusion in summer and fall months was a common occurrence under pre-development conditions and has been moderated in the contemporary period due to the operations of upstream reservoirs, which were designed to hold winter and spring runoff for release in summer and fall. This work also confirms a dramatic decadal-scale hydrologic shift in the watershed from very wet to very dry conditions during the late 19th and early 20th centuries; while not unprecedented, these shifts have been seen only a few times in the past millennium. This shift resulted in an increase in salinity intrusion in the first three decades of the 20th century, as documented through early records. Population growth and extensive watershed modification during this period exacerbated this underlying hydrologic shift. Putting this shift in the context of other anthropogenic drivers is important in understanding the historical response of the estuary and in setting salinity targets for estuarine restoration. By characterizing the long-term behavior of San Francisco Estuary, this work supports decision-making in the State of California related to flow and salinity management for restoration of the estuarine ecosystem.

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Seismische Erschütterungen und female empowerment: Erdbeben-Narrative und Gender vom 18. bis zum frühen 20. Jahrhundert

Zeitschrift für Germanistik ◽

10.3726/92165_553 ◽

2019 ◽

Vol 29 (3) ◽

pp. 553-572

Author(s):

GABY PAILER

Keyword(s):

20Th Century ◽

San Francisco ◽

Literary Texts ◽

Female Empowerment ◽

Early 20Th Century ◽

And Gender ◽

Theoretical Considerations

Abstract Der Beitrag untersucht Erdbeben-Narrative, d. h. seismische Erschütterungen als Motiv, Metapher, Agens und Medium in literarischen Texten variabler Genres vom 18. bis zum frühen 20. Jahrhundert. Er konzentriert sich auf die historisch desaströsen Ereignisse von Lissabon 1755, Messina 1783, Guadeloupe 1843 und San Francisco 1906 und ihre Diskurs- und Mediengeschichte. Die Ausführungen basieren auf theoretischen Überlegungen zu Vorstellungen von Anthropozän, Aufklärung und gender.This article examines earthquake narratives, i.e. seismic upheavals as motif, metaphor, agent, and medium within literary texts of various genres, from the 18th to the early 20th century. It is focused on the historical disastrous events of Lisbon 1755, Messina 1783, Guadeloupe 1843, and San Francisco 1906, and their discourse and media histories. The argument is based on theoretical considerations regarding notions of anthropocene, enlightenment, and gender.

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The Master of the Form

Asian Self-Representation at World's Fairs ◽

10.5117/9789462985636_ch02 ◽

2020 ◽

Author(s):

William Peterson

Keyword(s):

20Th Century ◽

San Francisco ◽

International Exhibition ◽

Early 20Th Century ◽

Japanese American ◽

Years Of Experience ◽

The West ◽

The Arts ◽

International Exposition ◽

Asian Migration

By the early 20th century, Japan was the master of the international exhibition format. With over fifty years of experience at world’s fairs in the West, Japan knew how to market its culture and products in a manner appealing to the Western consumer of both high art and decorative objects. The 1915 Panama Pacific International Exposition provided the country with a unique opportunity to create a strong and lasting imprint on American bodies in the country pavilion site with its famed gardens and exotic, kimono-clad women. As the epicenter of Asian migration, San Francisco also offered unique opportunities to further the power of Japonisme in the arts, while politicians in both countries used the event to champion Japanese-American relations.

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Reasons for Commuter Rail Electrification: Early 20th Century and Since 2000

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198119840621 ◽

2019 ◽

Vol 2673 (7) ◽

pp. 227-238 ◽

Cited By ~ 1

Author(s):

John G. Allen

Keyword(s):

New York ◽

20Th Century ◽

San Francisco ◽

Early 20Th Century ◽

Careful Study ◽

New Haven ◽

Railroad Industry ◽

Commuter Rail ◽

Passenger Trains ◽

Electric Traction

Commuter rail electrification is a complex, capital-intensive matter requiring careful study. Between 1905 and 1931, North American railroads inaugurated electrifications for commuter trains that survive today in New York; Philadelphia, Pennsylvania; Chicago, Illinois; and Montréal, Québec, Canada, as well as for intercity passenger trains between New Haven, Connecticut, and Washington, D.C. A renaissance in electrification is taking hold once more. Since 2000, three new-start electrifications have been placed in service: one for intercity passenger trains (between Boston, Massachusetts, and New Haven, Connecticut), and two others for commuter rail (in Mexico City, Mexico, and Denver, Colorado). Two more are proceeding forward (in Toronto, Ontario, Canada, and San Francisco, California). Despite the great changes caused throughout the railroad industry by the mid-20th century switch from steam to diesel, there is little change in the reasons for commuter railroad electrification in the two eras. Although the justification threshold is higher today than in the early 20th century, it has lowered somewhat as various considerations again converge in favor of electric traction. This is important, because electrification both requires and reinforces heavy ridership, and today’s resurgence of electrification is happening amid a sustained upswing in commuter rail ridership.

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