Soil and Stream Water Chemistry During Spring Snowmelt

1992 ◽  
Vol 23 (1) ◽  
pp. 13-26 ◽  
Author(s):  
W. H. Hendershot ◽  
L. Mendes ◽  
H. Lalande ◽  
F. Courchesne ◽  
S. Savoie
Keyword(s):  
Stream Water ◽  
Base Cations ◽  
Stream Chemistry ◽  
Stream Water Chemistry ◽  
The Matrix ◽  
Adsorption Desorption ◽  
The Relationship ◽  
Best Fit ◽  
Spring Snowmelt ◽  
Over Time

In order to determine how water flowpath controls stream chemistry, we studied both soil and stream water during spring snowmelt, 1985. Soil solution concentrations of base cations were relatively constant over time indicating that cation exchange was controlling cation concentrations. Similarly SO4 adsorption-desorption or precipitation-dissolution reactions with the matrix were controlling its concentrations. On the other hand, NO3 appeared to be controlled by uptake by plants or microorganisms or by denitrification since their concentrations in the soil fell abruptly as snowmelt proceeded. Dissolved Al and pH varied vertically in the soil profile and their pattern in the stream indicated clearly the importance of water flowpath on stream chemistry. Although Al increased as pH decreased, the relationship does not appear to be controlled by gibbsite. The best fit of calculated dissolved inorganic Al was obtained using AlOHSO4 with a solubility less than that of pure crystalline jurbanite.

Modelling stream water chemistry with snowmelt

1984 ◽  
Vol 305 (1124) ◽  
pp. 427-439 ◽  
Keyword(s):  
Ion Exchange ◽  
Water Chemistry ◽  
Seasonal Variations ◽  
Stream Water ◽  
Acid Precipitation ◽  
Exchange Reactions ◽  
Stream Water Chemistry ◽  
Reservoir Models ◽  
Southern Norway ◽  
Adsorption Desorption

Simple hydrochemical reservoir models based on the mobile anion concept are described for the Birkenes and Storgam a catchments in southern Norway with acidified stream water. Key processes modelled include water routing, sulphate adsorption-desorption, ion-exchange reactions, weathering and a gibbsite equilibrium condition. The models reproduce much of the daily and seasonal variations in stream water chemistry which have been observed over several years. Model considerations have been used in an attempt to explain the acidification of stream water in these two areas. It is hypothesized that soil acidification has occurred and that acid precipitation is at least partly responsible. The results are tentative largely because the models are derived from present-day stream water chemistry.

scholarly journals Linking groundwater travel times to stream chemistry, isotopic composition and catchment characteristics

2020 ◽  
Author(s):  
Elin Jutebring Sterte ◽  
Fredrik Lidman ◽  
Emma Lindborg ◽  
Ylva Sjöberg ◽  
Hjalmar Laudon
Keyword(s):  
Travel Time ◽  
Stream Water ◽  
Base Cations ◽  
Base Cation ◽  
Isotopic Signature ◽  
Stream Chemistry ◽  
Travel Times ◽  
Underlying Assumption ◽  
Tracking Model

Abstract. Understanding travel times of rain and snowmelt inputs transported through the subsurface environment to recipient surface waters is critical in many hydrological and biogeochemical investigations. In this study, a particle tracking model approach in Mike SHE was used to investigating the travel time of stream groundwater input to 14 partly nested, long-term monitored boreal sub-catchments. Based on previous studies in the area, we hypothesized that the main factor controlling groundwater travel times was catchment size. The modeled mean travel time (MTT) in the different sub-catchments ranged between 0.5 years and 3.6 years. Estimated MTTs were tested against the observed long-term winter isotopic signature (δ2H, δ18O) and chemistry (base cation concentration and pH) of the stream water. The underlying assumption was that older water would have an isotopic signature that resembles the long-term average precipitation input, while seasonal variations would be more apparent in catchments with younger water. Similarly, it was assumed that older water would be more affected by weathering, resulting in higher concentrations of base cations and higher pH. 10-year average winter values for stream chemistry were used for each sub-catchment. We found significant correlations between the estimated travel times and average water isotope signature (r = 0.80, p 

Sensitivity of pH in a boreal stream network to a potential decrease in base cations caused by forest harvest

2010 ◽  
Vol 67 (7) ◽  
pp. 1116-1125 ◽  
Author(s):  
Anneli Ågren ◽  
Ishi Buffam ◽  
Kevin Bishop ◽  
Hjalmar Laudon
Keyword(s):  
Forest Cover ◽  
Stream Water ◽  
Base Cations ◽  
Forest Harvest ◽  
Stream Network ◽  
Stream Length ◽  
Forestry Practices ◽  
Long Term Effect ◽  
Spring Snowmelt

Increased forest harvest with more whole-tree utilization can decrease base cations (BC) in soils and stream runoff. This paper analyses how reducing stream BC changes the capacity of a boreal stream network to buffer pH changes. We estimated change in stream pH during spring snowmelt in 60 locations throughout a 68 km2 boreal catchment in northern Sweden with different scenarios of BC removal from stream water ranging from 10 to 50 µequiv.·L–1. The pH decreased in all scenarios, and if BC decreased by 50 µequiv.·L–1, stream length with pH above the acid threshold pH 5 during spring snowmelt decreased from 82% to 44% of the stream network, whereas the stream length with pH above 5.5 decreased from 60% to 10%. The pH sensitivity of different stream reaches to reductions in BC was positively related to the slope of the catchment, forest cover, and forested mires, whereas it was negatively related to the percentage of agricultural fields. Because the long-term effect of different forestry practices on stream BC is unclear, there is all the more reason to evaluate BC sensitivity before, rather than after, eventual problems arise.

Investment Traits and Intelligence in Adulthood

2013 ◽  
Vol 34 (2) ◽  
pp. 82-89 ◽  
Author(s):  
Sophie von Stumm
Keyword(s):  
Individual Differences ◽  
Personality Traits ◽  
Fluid Intelligence ◽  
Need For Cognition ◽  
Openness To Experience ◽  
Intelligence Tests ◽  
Crystallized Intelligence ◽  
New Knowledge ◽  
The Relationship ◽  
Over Time

Intelligence-as-knowledge in adulthood is influenced by individual differences in intelligence-as-process (i.e., fluid intelligence) and in personality traits that determine when, where, and how people invest their intelligence over time. Here, the relationship between two investment traits (i.e., Openness to Experience and Need for Cognition), intelligence-as-process and intelligence-as-knowledge, as assessed by a battery of crystallized intelligence tests and a new knowledge measure, was examined. The results showed that (1) both investment traits were positively associated with intelligence-as-knowledge; (2) this effect was stronger for Openness to Experience than for Need for Cognition; and (3) associations between investment and intelligence-as-knowledge reduced when adjusting for intelligence-as-process but remained mostly significant.

Power Values and Power Distance Moderate the Relationship Between Workplace Supervisory Power and Job Satisfaction

2020 ◽  
Vol 19 (3) ◽  
pp. 135-141
Author(s):  
Kenneth D. Locke
Keyword(s):  
Job Satisfaction ◽  
Multilevel Modeling ◽  
Power Distance ◽  
European Social Survey ◽  
Social Survey ◽  
The Relationship ◽  
Workplace Power ◽  
Over Time

Abstract. Person–job (or needs–supplies) discrepancy/fit theories posit that job satisfaction depends on work supplying what employees want and thus expect associations between having supervisory power and job satisfaction to be more positive in individuals who value power and in societies that endorse power values and power distance (e.g., respecting/obeying superiors). Using multilevel modeling on 30,683 European Social Survey respondents from 31 countries revealed that overseeing supervisees was positively associated with job satisfaction, and as hypothesized, this association was stronger among individuals with stronger power values and in nations with greater levels of power values or power distance. The results suggest that workplace power can have a meaningful impact on job satisfaction, especially over time in individuals or societies that esteem power.

Emotional Impact Feedback Changes How We Remember Negative Autobiographical Experiences

2010 ◽  
Vol 57 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange
Keyword(s):  
Well Being ◽  
The Other ◽  
Personal Perspective ◽  
Emotional Impact ◽  
Potential Mechanism ◽  
Negative Experiences ◽  
Negative Memory ◽  
The Relationship ◽  
Negative Memories ◽  
Over Time

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.

Rethinking social remittances and the migration-development nexus from the perspective of time

2013 ◽  
Vol 10 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Peggy Levitt ◽  
Deepak Lamba-Nieves
Keyword(s):  
Social Influence ◽  
Change Over Time ◽  
Social Remittances ◽  
The Relationship ◽  
Migration And Development ◽  
Over Time

This article explores how the conceptualization, management, and measurement of time affect the migration-development nexus. We focus on how social remittances transform the meaning and worth of time, thereby changing how these ideas and practices are accepted and valued and recalibrating the relationship between migration and development. Our data reveal the need to pay closer attention to how migration’s impacts shift over time in response to its changing significance, rhythms, and horizons. How does migrants’ social influence affect and change the needs, values, and mind-frames of non-migrants? How do the ways in which social remittances are constructed, perceived, and accepted change over time for their senders and receivers?

Development and evaluation of trans-Amadi groundwater parameters: The integration of finite element techniques

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Finite Element ◽  
Polynomial Regression ◽  
Nitrate Concentration ◽  
Strong Relationship ◽  
Total Iron ◽  
Coefficient Of Determination ◽  
Port Harcourt ◽  
Polynomial Expression ◽  
The Relationship ◽  
Best Fit

Mathematical model was developed and evaluated to monitor and predict the groundwater characteristics of Trans-amadi region in Port Harcourt City. In this research three major components were considered such as chloride, total iron and nitrate concentration as well as the polynomial expression on the behavious on the concentration of each component was determined in terms of the equation of the best fit as well as the square root of the curve. The relationship between nitrate and distance traveled by Nitrate concentration by the model is given as Pc = 0.003x2 - 0.451x + 14.91with coefficient of determination, R² = 0.947, Chloride given as Pc = 0.000x2 - 0.071x + 2.343, R² = 0.951while that of Total Iron is given as Pc = 2E-05x2 - 0.003x + 0.110, R² = 0.930. All these show a strong relationship as established by Polynomial Regression Model. The finite element techniques are found useful in monitoring, predicting and simulating groundwater characteristics of Trans-amadi as well as the prediction on the variation on the parameters of groundwater with variation in time.

Changing Places: Rock Art and Holocene Landscapes in the Wadi al-Ajal, South-West Libya

2014 ◽  
Vol 12 (2) ◽  
pp. 165-182 ◽  
Author(s):  
Tertia Barnett ◽  
Maria Guagnin
Keyword(s):  
Spatial Analysis ◽  
Surface Water ◽  
Rock Art ◽  
Human Settlement ◽  
Gis Model ◽  
South West ◽  
Settlement Location ◽  
Central Sahara ◽  
The Relationship ◽  
Over Time

This article examines the relationship between rock art and landscape use by pastoral groups and early settled communities in the central Sahara from around 6000 BC to 1000 AD. During this period the region experienced significant climatic and environmental fluctuations. Using new results from a systematic survey in the Wadi al-Ajal, south-west Libya, our research combines data from over 2000 engraved rock art panels with local archaeological and palaeoenvironmental evidence within a GIS model. Spatial analysis of these data indicates a correspondence between the frequency of rock art sites and human settlement over time. However, while changes in settlement location were guided primarily by the constraints on accessibility imposed by surface water, the distribution of rock art relates to the availability of pasture and patterns of movement through the landscape. Although the reasons for these movements undoubtedly altered over time, natural routes that connected the Wadi al-Ajal and areas to the south continued to be a focus for carvings over several thousand years.

Adolescent Language: Models, Assessment, and Links to Reading

2019 ◽  
Author(s):  
Amanda Goodwin ◽  
Yaacov Petscher ◽  
Jamie Tock
Keyword(s):  
Reading Comprehension ◽  
Bifactor Model ◽  
Language Models ◽  
Multiple Group ◽  
Global Factor ◽  
Eighth Grade Students ◽  
Key Aspects ◽  
Future Work ◽  
The Relationship ◽  
Best Fit

Various models have highlighted the complexity of language. Building on foundational ideas regarding three key aspects of language, our study contributes to the literature by 1) exploring broader conceptions of morphology, vocabulary, and syntax, 2) operationalizing this theoretical model into a gamified, standardized, computer-adaptive assessment of language for fifth to eighth grade students entitled Monster, PI, and 3) uncovering further evidence regarding the relationship between language and standardized reading comprehension via this assessment. Multiple-group item response theory (IRT) across grades show that morphology was best fit by a bifactor model of task specific factors along with a global factor related to each skill. Vocabulary was best fit by a bifactor model that identifies performance overall and on specific words. Syntax, though, was best fit by a unidimensional model. Next, Monster, PI produced reliable scores suggesting language can be assessed efficiently and precisely for students via this model. Lastly, performance on Monster, PI explained more than 50% of variance in standardized reading, suggesting operationalizing language via Monster, PI can provide meaningful understandings of the relationship between language and reading comprehension. Specifically, considering just a subset of a construct, like identification of units of meaning, explained significantly less variance in reading comprehension. This highlights the importance of considering these broader constructs. Implications indicate that future work should consider a model of language where component areas are considered broadly and contributions to reading comprehension are explored via general performance on components as well as skill level performance.

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