The impact of spatial and temporal variability of anomalous diffusion flow mechanisms on reservoir performance in structurally complex porous media

Abstract. The spatio-temporal variability of stream water temperatures was investigated at six locations on the Girnock Burn (30km2 catchment), Cairngorms, Scotland over three hydrological years between 1998 and 2002. The key site-specific factors affecting the hydrology and climatology of the sampling points were investigated as a basis for physical process inference. Particular emphasis was placed on assessing the effects of riparian forest in the lower catchment versus the heather moorland riparian zones that are spatially dominant in the upper catchment. The findings were related to river heat budget studies that provided process detail. Gross changes in stream temperature were affected by the annual cycle of incoming solar radiation and seasonal changes in hydrological and climatological conditions. Inter-annual variation in these controlling variables resulted in inter-annual variability in thermal regime. However, more subtle inter-site differences reflected the impact of site-specific characteristics on various components of the river energy budget. Inter-site variability was most apparent at shorter time scales, during the summer months and for higher stream temperatures. Riparian woodland in the lower catchment had a substantial impact on thermal regime, reducing diel variability (over a period of 24 hours) and temperature extremes. Observed inter-site differences are likely to have a substantial effect on freshwater ecology in general and salmonid fish in particular. Keywords: temperature, thermal regime, forest, salmon, hydrology, Girnock Burn, Cairngorm

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The influence of a new water infrastructure development on the relative abundance of two Australian freshwater turtle species

Australian Journal of Zoology ◽

10.1071/zo17082 ◽

2018 ◽

Vol 66 (1) ◽

pp. 57 ◽

Cited By ~ 1

Author(s):

Natalie J. Clark ◽

Courtenay E. Mills ◽

Nicolette A. Osborne ◽

Kerry M. Neil

Keyword(s):

Relative Abundance ◽

Temporal Variability ◽

Monitoring Program ◽

Freshwater Turtle ◽

Spatial And Temporal Variability ◽

Main Body ◽

Water Infrastructure ◽

Turtle Species ◽

Australian Freshwater ◽

The Impact

Development of water infrastructure benefits water security and agriculture but poses risks to habitat and aquatic fauna. Wyaralong Dam was constructed on Teviot Brook in 2010 to provide future urban water supplies for South East Queensland, Australia. Construction of the dam created a large impoundment area and environmental impact assessment predicted significant impacts upon resident freshwater turtle species and their habitats. Differences in habitat requirements, life-history characteristics and sensitivity to change between the Macquarie River turtle (Emydura macquarii macquarii) and the common saw-shelled turtle (Myuchelys latisternum) were expected to influence the impact of the dam on the spatial and temporal abundance of these species. The relative abundance of each species was monitored at sites located within, upstream and downstream of the impoundment across wet and dry seasons during the dam’s first five years of operation. The results of this monitoring program indicate that spatial and temporal variability in the relative abundance of E. macquarii macquarii and M. latisternum occurred during the study but not all expected impacts were realised. Contrary to expectation, the relative abundance of E. macquarii macquarii did not increase over time within, upstream or downstream of the dam. M. latisternum showed greater temporal variability at some sites; however, no clear relationship between relative abundance and operational years was observed during the monitoring program. Spatial variability in relative abundance between sites was dependent upon season, with trends generally consistent across both turtle species. Where differences between species were observed, these are suspected to have resulted from the influence of environmental conditions on species-specific movement behaviours. The monitoring program confirmed the use of the upper limits of the impoundment and the plunge pool below the dam wall by both turtle species but relative abundance within the main body of the impoundment remained low throughout monitoring. The results of the study allow for consideration of the suitability of predefined management measures and the development of recommendations for future monitoring programs prescribed for water infrastructure developments.

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Approaches to evaluate spatial and temporal variability of deep marine sediment characteristics under the impact of dense water formation events

Mediterranean Marine Science ◽

10.12681/mms.22581 ◽

2020 ◽

Author(s):

XAVIER DURRIEU de MADRON ◽

MARION STABHOLZ ◽

LARS-ERIC HEIMBÜRGER-BOAVIDA ◽

DOMINIQUE AUBERT ◽

PHILIPPE KERHERVÉ ◽

...

Keyword(s):

Spatial Variability ◽

Temporal Variability ◽

Small Scale ◽

Spatial And Temporal Variability ◽

Geochemical Composition ◽

Dense Water ◽

Water Formation ◽

Dense Water Formation ◽

Northwestern Mediterranean Sea ◽

The Impact

Dense shelf water cascading and open-ocean convection frequently occurs in the Gulf of Lions, northwestern Mediterranean Sea. These intense dense water formation events are capable of supplying large amounts of particulate matter as well as remobilizing and dispersing local sediments and, therefore, are thought to leave an imprint on superficial deposits. Here, we compared the spatial variability of the superficial sediment composition (grain size, organic parameters, and metals) at different scales (from decimetric to kilometric) on the continental slope and rise with the temporal variability linked to the occurrence of intense dense water formation events. The spatial and temporal variability of the geochemical composition of deep sediments was assessed using multivariate and geostatistical analysis. The results indicate that, on the outer reach of the Cap de Creus Canyon, where both processes interact, no clear relation was found between the temporal variability of the superficial sediment and the deep-water formation events, and that the small-scale spatial variability of the sediment is masking the temporal variability. Measurements across the southern slope indicate the presence of a somehow distinct geochemical signature that likely results from the influence of recurrent intense, dense water formation events as well as an unabating bottom trawling activity.

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Spatial and temporal variability of water-filled crevasse hydrologic states along the shear margins of Jakobshavn Isbrae, Greenland

10.5194/tc-2017-86 ◽

2017 ◽

Cited By ~ 1

Author(s):

Casey A. Joseph ◽

Derrick J. Lampkin

Keyword(s):

Temporal Variability ◽

Large Strain ◽

Water Injection ◽

Greenland Ice Sheet ◽

Spatial And Temporal Variability ◽

Strain Rates ◽

Ice Streams ◽

Lower Elevation ◽

Melt Water ◽

The Impact

Abstract. The impact of melt water injection into ice streams over the Greenland Ice Sheet is not well understood. Water-filled crevasses along the shear margins of Jakobshavn Isbræ are known to fill and drain, resulting in weakening of the shear margins due to reduced basal friction. Seasonal variability in the hydrologic dynamics of these features has not been quantified. In this work, we characterize the spatial and temporal variability in the hydrological state (filled or drained) of these water-filled crevasse systems. A fusion of multi-sensor optical satellite imagery was used to examine hydrologic states from 2000 to 2015. The monthly distribution of crevasse systems observed as water filled is unimodal with peak number of filled days during the month of July at 329 days, while May has the least at 15. Over the study period the occurrence of drainage within a given season increases. Inter-seasonal drain frequencies over these systems ranged from 0 to 5. The frequency of multi-drainage events are correlated with warmer seasons and large strain rates. Over the study period, summer temperatures averaged from −1 and 2 °C and tensile strain rates have increased to as high as ~ 1.2 s-1. Intermittent melt water input during hydrofracture drainage responsible for transporting surface water to the bed is largely facilitated by high local tensile stresses. Drainage due to fracture propagation may be increasingly modulated by ocean-induced calving dynamics for the lower elevation ponds. Water-filled crevasses could expand in extent and volume as temperatures increase resulting in regional amplification of ice mass flux into the ice stream system.

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ANÁLISE COMPARATIVA DO REGIME HÍDRICO E TÉRMICO DE DOIS SÍTIOS EXPERIMENTAIS NO PAMPA

Ciência e Natura ◽

10.5902/2179460x20180 ◽

2016 ◽

Vol 38 ◽

pp. 209

Author(s):

Cláudio Alberto Teichrieb ◽

Pablo Eli Soares de Oliveira ◽

Tamires Zimmer ◽

Cristiano Maboni ◽

Daniel Michelon dos Santos ◽

...

Keyword(s):

Climate Change ◽

Carbon Dioxide ◽

Thermal Conductivity ◽

Water Content ◽

Temporal Variability ◽

Spatial And Temporal Variability ◽

Natural Field ◽

Field Extensions ◽

Pampa Biome ◽

The Impact

In the last 15-20 years has greatly increased research on the problem of climate change, necessitating a demand for reliable measurements of absorption and emission of carbon dioxide, methane, as well as the impact on water resources. In the biome Pampa are the largest continuous natural field extensions, requiring a monitoring of water and temperature regime on the ground. The water content of the soil has spatial and temporal variability affecting many hydrological processes and determining this is needed since the soil store and provide the water and nutrients for the plants, thus involving relationships water-soil-plant-atmosphere. In this work, we compared the water content behavior of the soil at depths of 10, 30 and 50 cm, the temperature of the soil at depths of 5, 15 and 30 cm, heat flux in soil installed 10 cm deep and the thermal conductivity was determined in two experimental sites in the Pampa biome, for the period 01.01.2015 to 06.31.2015. It was found that there are differences between the sites in the capacity to retain moisture in the soil and in the ability to store energy in the soil for the study period.

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Spatial and Temporal Variability of Ice Algal Trophic Markers—With Recommendations about Their Application

Journal of Marine Science and Engineering ◽

10.3390/jmse8090676 ◽

2020 ◽

Vol 8 (9) ◽

pp. 676

Author(s):

Eva Leu ◽

Thomas A. Brown ◽

Martin Graeve ◽

Jozef Wiktor ◽

Clara J. M. Hoppe ◽

...

Keyword(s):

Stable Isotope ◽

Sea Ice ◽

Temporal Variability ◽

Climate Change Impacts ◽

Isotope Ratios ◽

Arctic Sea Ice ◽

Stable Isotope Ratios ◽

Spatial And Temporal Variability ◽

Web Studies ◽

The Impact

Assessing the relative importance of sea ice algal-based production is often vital for studies about climate change impacts on Arctic marine ecosystems. Several types of lipid biomarkers and stable isotope ratios are widely used for tracing sea ic-associated (sympagic) vs. pelagic particulate organic matter (POM) in marine food webs. However, there has been limited understanding about the plasticity of these compounds in space and time, which constrains the robustness of some of those approaches. Furthermore, some of the markers are compromised by not being unambiguously specific for sea ice algae, whereas others might only be produced by a small sub-group of species. We analyzed fatty acids, highly branched isoprenoids (HBIs), stable isotope ratios of particulate organic carbon (POC) (δ13C), as well as δ13C of selected fatty acid markers during an Arctic sea ice algal bloom, focusing on spatial and temporal variability. We found remarkable differences between these approaches and show that inferences about bloom characteristics might even be contradictory between markers. The impact of environmental factors as causes of this considerable variability is highlighted and explained. We emphasize that awareness and, in some cases, caution is required when using lipid and stable isotope markers as tracers in food web studies and offer recommendations for the proper application of these valuable approaches.

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Modeling characterization of the vertical and temporal variability of environmental DNA in the mesopelagic ocean

Scientific Reports ◽

10.1038/s41598-021-00288-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Elizabeth Andruszkiewicz Allan ◽

Michelle H. DiBenedetto ◽

Andone C. Lavery ◽

Annette F. Govindarajan ◽

Weifeng G. Zhang

Keyword(s):

Vertical Distribution ◽

Water Column ◽

Temporal Variability ◽

Mechanistic Model ◽

Temporal Distribution ◽

Environmental Dna ◽

Vertical Displacement ◽

Physical Parameters ◽

Spatial And Temporal Variability ◽

The Impact

AbstractIncreasingly, researchers are using innovative methods to census marine life, including identification of environmental DNA (eDNA) left behind by organisms in the water column. However, little is understood about how eDNA is distributed in the ocean, given that organisms are mobile and that physical and biological processes can transport eDNA after release from a host. Particularly in the vast mesopelagic ocean where many species vertically migrate hundreds of meters diurnally, it is important to link the location at which eDNA was shed by a host organism to the location at which eDNA was collected in a water sample. Here, we present a one-dimensional mechanistic model to simulate the eDNA vertical distribution after its release and to compare the impact of key biological and physical parameters on the eDNA vertical and temporal distribution. The modeled vertical eDNA profiles allow us to quantify spatial and temporal variability in eDNA concentration and to identify the most important parameters to consider when interpreting eDNA signals. We find that the vertical displacement by advection, dispersion, and settling has limited influence on the eDNA distribution, and the depth at which eDNA is found is generally within tens of meters of the depth at which the eDNA was originally shed from the organism. Thus, using information about representative vertical migration patterns, eDNA concentration variability can be used to answer ecological questions about migrating organisms such as what depths species can be found in the daytime and nighttime and what percentage of individuals within a species diurnally migrate. These findings are critical both to advance the understanding of the vertical distribution of eDNA in the water column and to link eDNA detection to organism presence in the mesopelagic ocean as well as other aquatic environments.

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Corrigendum to: Partitioning spatial and temporal variability of tropical near-shore macrobenthic assemblages affected by natural and anthropogenic disturbances

Marine and Freshwater Research ◽

10.1071/mf10165_co ◽

2011 ◽

Vol 62 (7) ◽

pp. 885

Author(s):

P. Rodríguez-Pliego ◽

H. A. Hernández-Arana ◽

P.-L. Ardisson

Keyword(s):

Temporal Variability ◽

Temporal Analysis ◽

Anthropogenic Disturbances ◽

Climatic Conditions ◽

Analytical Models ◽

Spatial And Temporal Variability ◽

Coastal Zones ◽

Macrobenthic Assemblages ◽

Near Shore ◽

The Impact

Coastal zones throughout the world are subject to natural and anthropogenic disturbances that modify the natural assemblages. The present study determined the response of the assemblage of macrobenthic invertebrates to the presence of a pier and natural climatic variations. Two analytical models were considered; one was an asymmetric model that permitted the comparison of the sector closest to the pier (impact) with the average of the sectors located further away (controls); the other was a three-way model that enabled the three sectors within the area to be analysed. With both models, the differences were compared among the sampling periods and the scale at which the variation in the data was greatest. No differences were detected among individual sectors or between the control and impact sectors. However, significant differences were found among the four periods. The zone closest to the pier presented greater temporal variability. This relationship suggests that the pier affecting the assemblage and the impact may be increased by the climatic conditions prevalent in the zone. It is necessary to establish a broader temporal analysis and a more detailed analysis of the structure and composition of the benthic assemblage to elucidate this temporal and spatial variability.

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Spatio-temporal variability of erosivity in Mato Grosso, Brazil

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2276 ◽

2018 ◽

Vol 13 (6) ◽

pp. 1

Author(s):

Luis Augusto Di Loreto Di Raimo ◽

Ricardo Santos Silva Amorim ◽

Eduardo Guimarães Couto ◽

Rodolfo Luiz Bezerra Nóbrega ◽

Gilmar Nunes Torres ◽

...

Keyword(s):

Temporal Variability ◽

Vegetation Change ◽

Rain Gauge ◽

Mean Value ◽

Rainfall Erosivity ◽

Spatial And Temporal Variability ◽

Mato Grosso ◽

North West ◽

R Factor ◽

The Impact

The impact of rainfall on surfaces lacking vegetal cover can dissociate soil particles, thereby initiating the erosion process. This is known as rainfall erosivity and is expressed by the R factor in the Universal Soil Loss Equation. Agricultural areas often show seasonally erosion susceptibility throughout the year due to oscillations of the soil exposure rate and the vegetation change. Considering that approximately 30 million ha of the Mato Grosso State in Brazil is used for agriculture, this study aimed to predict and map the spatial and temporal variability of its territory. We evaluated the monthly (EI30) and annual (R) erosivity for 158 rain gauge stations and spatialized the values of EI30 and R by the Kriging method. It was observed that R values ranked as very high in the north, and high and medium-high in the south of Mato Grosso state. The mean value is 8835 MJ mm ha-1 h-1 year-1, considered high. Ninety-one percent of the annual erosivity was concentrated in the period between October and April, corresponding to the rainy season. The highest R factor values were found in the macro-regions of the northwest, north, west and medium-north of Mato Grosso State.

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