Effects of Winter Floods on Fishes in the Sierra Nevada

1988 ◽  
Vol 45 (12) ◽  
pp. 2195-2200 ◽  
Author(s):  
Don C. Erman ◽  
Edmund D. Andrews ◽  
Michael Yoder-Williams
Keyword(s):  
Sierra Nevada ◽  
Brook Trout ◽  
Critical Role ◽  
Maximum Flow ◽  
Timber Harvesting ◽  
Snow Accumulation ◽  
Buffer Strips ◽  
Material Transport ◽  
Bed Material ◽  
The Impact

Winter floods in the Sierra Nevada mountains kill age 0 class brook trout (Salvelinus fontinalis) and Paiute sculpin (Cottus beldingi) because bed-material transport increases greatly when high flows are constrained by snow banks. In February 1982, dead Paiute sculpin were collected while sampling bedload during a rain-on-snow flood. Population estimates by electrofishing at nine permanent stations the following summer showed that density (3586∙ha−1) and biomass(12.9 kg∙ha−1) of Paiute sculpin were lower than the respective means (12 017∙ha−1 and 40.3 kg∙ha−1) obtained during previous studies from 1952 to 1961. These estimates were also below those obtained in 1956, after the largest winter flood from 1952 to 1961. Brook trout fry were also less abundant in 1982 than previously reported. Maximum flow depth, rather than discharge, were the likely cause offish mortality. Winter floods are severe because accumulated snowpack increases the effective height of the streambank and confines most or all of a rain-on-snow flood within the channel. Shear forces on the bed increase and as a result bed-material transport increases rapidly. These conditions directfy kill many benthic-living fishes such as the Paiute sculpin or buried eggs of fall-spawning fishes such as the brook trout by mechanical grinding or crushing. The impact of snow-constrained floods was not uniform along Sagehen Creek due to patchiness in types of riparian canopy. The relationship among canopy cover, snow accumulation, and winter floods points to one more critical role that buffer strips may play in ameliorating effects of timber harvesting.

scholarly journals The Value of Accurate High-Resolution and Spatially Continuous Snow Information to Streamflow Forecasts

2019 ◽  
Vol 20 (4) ◽  
pp. 731-749 ◽  
Author(s):  
Dongyue Li ◽  
Dennis P. Lettenmaier ◽  
Steven A. Margulis ◽  
Konstantinos Andreadis
Keyword(s):  
High Resolution ◽  
Sierra Nevada ◽  
Snow Accumulation ◽  
Forecast Errors ◽  
Streamflow Forecasting ◽  
Streamflow Forecast ◽  
Physically Based ◽  
Streamflow Forecasts ◽  
Seasonal Streamflow ◽  
The Impact

Abstract Previous studies have shown limited success in improving streamflow forecasting for snow-dominated watersheds using physically based models, primarily due to the lack of reliable snow water equivalent (SWE) information. Here we use a hindcasting approach to evaluate the potential benefit that a high-resolution, spatiotemporally continuous, and accurate SWE reanalysis product would have on the seasonal streamflow forecast in the snow-dominated Sierra Nevada mountains of California if such an SWE product were available in real time. We tested the efficacy of a physically based ensemble streamflow prediction (ESP) framework when initialized with the reanalysis SWE. We reinitialized the SWE over the Sierra Nevada at the time when the Sierra Nevada had domain-wide annual maximum SWE for each year in 1985–2015, and on 1 February of the driest years within the same period. The early season forecasts on 1 February provide valuable lead time for mitigating the impact of drought. In both experiments, initializing the ESP with the reanalysis SWE reduced the seasonal streamflow forecast errors; compared with existing operational statistical forecasts, the peak-annual SWE insertion and the 1 February SWE insertion reduced the overall root-mean-square error of the seasonal streamflow forecasts by 13% and 23%, respectively, over the 13 major rivers draining the Sierra Nevada. The benefits of the reanalysis SWE insertion are more pronounced in areas with greater snow accumulation, while the complex snow and runoff-generation processes in low-elevation areas impede the forecasting skill improvement through SWE reinitialization alone.

Chinese in the Woods

2015 ◽  
Author(s):  
Sue Fawn Chung
Keyword(s):  
Nineteenth Century ◽  
Sierra Nevada ◽  
American West ◽  
Critical Role ◽  
Work Relationships ◽  
Late Nineteenth Century ◽  
Chinese Workers ◽  
The Impact ◽  
Boom Period

Though recognized for their work in the mining and railroad industries, the Chinese also played a critical role in the nineteenth-century lumber trade. This book continues an examination of the impact of Chinese immigrants on the American West by bringing to life the tensions, towns, and lumber camps of the Sierra Nevada during a boom period of economic expansion. Chinese workers, like whites, labored as wood cutters and flume-herders, lumber jacks and loggers. Exploding the myth of the Chinese as a docile and cheap labor army, the book shows Chinese laborers earned wages similar to those of non-Asians. Men working as camp cooks, among other jobs, could even make more. At the same time, the book draws on archives and archaeology to reconstruct everyday existence, offering evocative portraits of camp living, small town life, personal and work relationships, and the production and technical aspects of a dangerous trade. The book examines the role of the Chinese in the lumber trade in the American West during the late nineteenth century, with a focus on the Sierra Nevada in the 1870s to 1890s. It looks at Chinese laborers' contribution to the building of the American West by analyzing their migration, their communities and lifestyles, lived experiences, transnationalism, and their work in relationship to mining and railroad construction.

The thermal regimes of brook trout incubation habitats and evidence of changes during forestry operations

2002 ◽  
Vol 32 (7) ◽  
pp. 1200-1207 ◽  
Author(s):  
R Allen Curry ◽  
David A Scruton ◽  
Keith D Clarke
Keyword(s):  
Surface Water ◽  
Brook Trout ◽  
Temperate Forest ◽  
Hyporheic Zone ◽  
Timber Harvesting ◽  
Riparian Buffer ◽  
Buffer Strips ◽  
Buffer Strip ◽  
Clear Cut ◽  
Thermal Regimes

The thermal regimes in streambed substrates used by brook trout, Salvelinus fontinalis Mitchell, for incubation of embryos were examined in reference and treatment (0- and 20-m riparian buffer strips) streams in a clear-cut harvested, northern temperate forest of western Newfoundland. In these streams, incubation habitats (redds) were primarily composed of downwelling surface waters with variable but minor mixing of upwelling groundwater. The resulting incubation temperatures were cold (<1°C) and surface water temperatures were accurate predictors of redd temperatures. Both treatment streams displayed evidence of warming in the fall and spring of the 2 years beginning the year of initial harvesting. The increase was most pronounced in the stream without a riparian buffer strip. Clear-cut harvesting with and without a riparian buffer strip altered the thermal regime of surface water and the hyporheic zone in this northern temperate forest where, in addition to salmonid incubation, many biological processes take place. The potential for impacts on stream ecosystems is estimated to be high for the managed forests of this region. Future studies should strive to enhance our understanding of the hydrological connections between forests and streams on this landscape to determine the full effects of timber harvesting on the hydrology and biology of a watershed and its streams.

scholarly journals The upper Odra as a case study of the impact of channel regulation on its morphodynamics

2014 ◽  
Vol 46 (4) ◽  
pp. 353-361
Author(s):  
Agnieszka Czajka
Keyword(s):  
Sediment Transport ◽  
Material Transport ◽  
Channel Dynamics ◽  
Channel Regulation ◽  
Before And After ◽  
Odra River ◽  
The One ◽  
Bed Material ◽  
The Impact

Abstract The upper Odra as a case study of the impact of channel regulation on its morphodynamics. The aim of the research was to compare morphodynamics of the Odra river channel in three different sectors and to find the main difference in the way of sediment transport before and after regulation in meandering, straight and sinuous channel sectors and compare the data with those calculated for reconstructed, natural channel of the Odra river. Sediment transport in discussed sectors was compared for average, bankfull and flood discharges and it proceeds in different ways. Morphodynamics of the preregulated Odra was most similar to the one currently observed in the meandering section. Also the dynamics of bed-material transport and, consequently, the possibility of the occurrence and disappearance of channel forms is greatly varied among the studied sectors. As it was assumed, a diversified channel geometry imposes water flow, which entails a series of processes shaping the channel dynamics.

Response of U.S. West Coast Mountain Snowpack to Local Sea Surface Temperature Perturbations: Insights from Numerical Modeling and Machine Learning

2021 ◽  
Vol 22 (4) ◽  
pp. 1045-1062
Author(s):  
Xiaodong Chen ◽  
L. Ruby Leung ◽  
Yang Gao ◽  
Ying Liu
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sierra Nevada ◽  
West Coast ◽  
Land Surface ◽  
Snow Accumulation ◽  
Sea Surface ◽  
Neural Network Models ◽  
The Impact ◽  
Precipitation And Temperature

AbstractSea surface temperature (SST) significantly modulates the precipitation and temperature over land, with important consequences on land surface processes such as snowpack. Compared to the impact of remote SST, the effect of nearshore/local SST is less well understood. In this study, the impact of local SST on the mountain snowpack of the U.S. West Coast is investigated using two 6-km regional climate simulations driven by the same lateral boundary conditions but with time-varying versus time-invariant and warmer local SSTs during 2003–15. Results show that local SST warming leads to warmer winter with more precipitation over the mountains. Meanwhile, the removal of SST temporal variability results in reduced temperature variability but increased precipitation variability. As a result, winter snow accumulation decreases by ~200 mm per season in the Cascade Mountains in the north but increases by ~100 mm per season in the Sierra Nevada in the south. Such a dipole response results from the competing effects of precipitation and temperature change at different elevations and are amplified by the enhanced atmospheric river moisture transport. To further delineate the relative contributions of different meteorological factors to the snowpack response, two neural network models were developed to predict the snow behaviors at seasonal and monthly scales. These models reveal the dominant influence of the total amount and the average temperature of precipitation on the snowpack response. These findings highlight the sensitivity of mountain snowpack to local SST in the western United States and underscore the importance of local SST and atmospheric rives to accurate snowpack estimations for water management.

The Laryngeal Epithelium in Reflux

2011 ◽  
Vol 21 (3) ◽  
pp. 112-117 ◽  
Author(s):  
Elizabeth Erickson-Levendoski ◽  
Mahalakshmi Sivasankar
Keyword(s):  
Laryngopharyngeal Reflux ◽  
Critical Role ◽  
Structure And Function ◽  
Laryngeal Disease ◽  
Health And Disease ◽  
And Function ◽  
The Impact

The epithelium plays a critical role in the maintenance of laryngeal health. This is evident in that laryngeal disease may result when the integrity of the epithelium is compromised by insults such as laryngopharyngeal reflux. In this article, we will review the structure and function of the laryngeal epithelium and summarize the impact of laryngopharyngeal reflux on the epithelium. Research investigating the ramifications of reflux on the epithelium has improved our understanding of laryngeal disease associated with laryngopharyngeal reflux. It further highlights the need for continued research on the laryngeal epithelium in health and disease.

ASSESSMENT OF HYDROLOGICAL CHANGES IN THE ŠUŠVĖ RIVER

2015 ◽  
Author(s):  
Gražina ŽIBIENĖ ◽  
Alvydas ŽIBAS ◽  
Goda BLAŽAITYTĖ
Keyword(s):  
Hydrological Regime ◽  
Maximum Flow ◽  
Environmental Flow ◽  
Physical Structure ◽  
River Channels ◽  
Hydrologic Alteration ◽  
Water Conditions ◽  
Flow Components ◽  
The Impact ◽  
Large Floods

The construction of dams in rivers negatively affects ecosystems because dams violate the continuity of rivers, transform the biological and physical structure of the river channels, and the most importantly – alter the hydrological regime. The impact on the hydrology of the river can occur through reducing or increasing flows, altering seasonality of flows, changing the frequency, duration and timing of flow events, etc. In order to determine the extent of the mentioned changes, The Indicators of Hydrologic Alteration (IHA) software was used in this paper. The results showed that after the construction of Angiriai dam, such changes occurred in IHA Parameters group as: the water conditions of April month decreased by 31 %; 1-day, 3-days, 7-days and 30-days maximum flow decreased; the date of minimum flow occurred 21 days later; duration of high and low pulses and the frequency of low pulses decreased, but the frequency of high pulses increased, etc. The analysis of the Environmental Flow Components showed, that the essential differences were recorded in groups of the small and large floods, when, after the establishment of the Šušvė Reservoir, the large floods no longer took place and the probability of frequency of the small floods didn’t exceed 1 time per year.

scholarly journals The lung–gut axis during viral respiratory infections: the impact of gut dysbiosis on secondary disease outcomes

2021 ◽  
Author(s):  
Valentin Sencio ◽  
Marina Gomes Machado ◽  
François Trottein
Keyword(s):  
Gut Microbiota ◽  
Bacterial Infections ◽  
Respiratory Infections ◽  
Critical Role ◽  
Good Health ◽  
Disease Outcomes ◽  
And Function ◽  
Viral Respiratory Infections ◽  
The Impact ◽  
Viral Respiratory

AbstractBacteria that colonize the human gastrointestinal tract are essential for good health. The gut microbiota has a critical role in pulmonary immunity and host’s defense against viral respiratory infections. The gut microbiota’s composition and function can be profoundly affected in many disease settings, including acute infections, and these changes can aggravate the severity of the disease. Here, we discuss mechanisms by which the gut microbiota arms the lung to control viral respiratory infections. We summarize the impact of viral respiratory infections on the gut microbiota and discuss the potential mechanisms leading to alterations of gut microbiota’s composition and functions. We also discuss the effects of gut microbial imbalance on disease outcomes, including gastrointestinal disorders and secondary bacterial infections. Lastly, we discuss the potential role of the lung–gut axis in coronavirus disease 2019.

scholarly journals Methionine Diet Evoked Hyperhomocysteinemia Causes Hippocampal Alterations, Metabolomics Plasma Changes and Behavioral Pattern in Wild Type Rats

2021 ◽  
Vol 22 (9) ◽  
pp. 4961
Author(s):  
Maria Kovalska ◽  
Eva Baranovicova ◽  
Dagmar Kalenska ◽  
Anna Tomascova ◽  
Marian Adamkov ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Brain Area ◽  
Critical Role ◽  
Cerebrovascular Diseases ◽  
Behavioral Pattern ◽  
Cell Physiology ◽  
Male Wistar Rats ◽  
High Level ◽  
Hippocampal Alterations ◽  
The Impact

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons’ vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in “methylation index” of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake.

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