Multi-scale streambed topographic and discharge effects on hyporheic exchange at the stream network scale in confined streams

2014 ◽  
Vol 519 ◽  
pp. 1997-2011 ◽  
Author(s):  
Alessandra Marzadri ◽  
Daniele Tonina ◽  
James A. McKean ◽  
Matthew G. Tiedemann ◽  
Rohan M. Benjankar
Keyword(s):  
Hyporheic Exchange ◽  
Stream Network ◽  
Multi Scale ◽  
Network Scale

A review of spatial statistical approaches to modeling water quality

2019 ◽  
Vol 43 (6) ◽  
pp. 801-826 ◽  
Author(s):  
Janardan Mainali ◽  
Heejun Chang ◽  
Yongwan Chun
Keyword(s):  
Water Quality ◽  
Spatial Autocorrelation ◽  
Spatial Regression ◽  
Model Performance ◽  
Spatial Relations ◽  
Predictor Variables ◽  
Stream Network ◽  
Multi Scale ◽  
Straight Line Distance ◽  
New Research

We review different regression models related to water quality that incorporate spatial aspects in their model. Spatial aspects refer to the location of different sites and are usually characterized by the distance between different points and directions by which they are related to each other. We focus on spatial lag and error, spatial eigenvector-based, geographically weighted regression, and spatial-stream-network-based models. We evaluated different studies using these methods based on how they dealt with clustering (spatial autocorrelation) of response variables, incorporated those clustering in the error (residual spatial autocorrelation), used multi-scale processes, and improved the model performance. The water-quality-based regression modeling approaches are shifting from straight-line distance-based spatial relations to upstream–downstream relations. Calculation of spatial autocorrelation and residual spatial autocorrelation was dependent upon the type of spatial regression used. The weights matrix is used as available in the software and most of the studies did not attempt to modify it. Different scale processes like certain distance from rivers versus consideration of entire watersheds are dealt with separately in most of the studies. Generally, the capacity of the predictor variables to predict the response variable significantly improves when spatial regressions are used. We identify new research directions in terms of spatial considerations, weights matrix construction, inclusion of multi-scale processes, and identification of predictor variables in such models.

scholarly journals Multi-scale modelling of rubber-like materials and soft tissues: an appraisal

2016 ◽  
Vol 472 (2187) ◽  
pp. 20160060 ◽  
Author(s):  
G. Puglisi ◽  
G. Saccomandi
Keyword(s):  
Mathematical Models ◽  
Phenomenological Models ◽  
Mechanical Behaviour ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Multi Scale ◽  
Bioinspired Materials ◽  
Macroscopic Properties ◽  
Network Scale ◽  
Scale Modelling

We survey, in a partial way, multi-scale approaches for the modelling of rubber-like and soft tissues and compare them with classical macroscopic phenomenological models. Our aim is to show how it is possible to obtain practical mathematical models for the mechanical behaviour of these materials incorporating mesoscopic (network scale) information. Multi-scale approaches are crucial for the theoretical comprehension and prediction of the complex mechanical response of these materials. Moreover, such models are fundamental in the perspective of the design, through manipulation at the micro- and nano-scales, of new polymeric and bioinspired materials with exceptional macroscopic properties.

Modeling Stream Network-Scale Variation in Coho Salmon Overwinter Survival and Smolt Size

2009 ◽  
Vol 138 (3) ◽  
pp. 564-580 ◽  
Author(s):  
Joseph L. Ebersole ◽  
Mike E. Colvin ◽  
Parker J. Wigington ◽  
Scott G. Leibowitz ◽  
Joan P. Baker ◽  
...  
Keyword(s):  
Coho Salmon ◽  
Stream Network ◽  
Overwinter Survival ◽  
Network Scale ◽  
Scale Variation

scholarly journals Scaling down hyporheic exchange flows: from catchments to reaches

2017 ◽  
Author(s):  
Chiara Magliozzi ◽  
Robert Grabowski ◽  
Aaron I. Packman ◽  
Stefan Krause
Keyword(s):  
Hyporheic Zone ◽  
Ecological Factors ◽  
Field Studies ◽  
Temporal Variations ◽  
Hyporheic Exchange ◽  
Exchange Flows ◽  
Multi Scale ◽  
Modelling Studies ◽  
Groundwater Systems ◽  
Isolated Systems

Abstract. Rivers are not isolated systems but continuously interact with the subsurface from upstream to downstream. In the last few decades, research on the hyporheic zone (HZ) from many perspectives has increased appreciation of the hydrological importance and ecological significance of connected river and groundwater systems. Although recent reviews, modelling and field studies have explored hydrological, biogeochemical and ecohydrological processes in the HZ at relatively small scales (bedforms to reaches), a comprehensive understanding of the factors driving the hyporheic exchange flows (HEF) at larger scales is still missing. To date, there is fragmentary information on how hydroclimatic, hydrogeologic, topographic, anthropogenic and ecological factors interact to drive hyporheic exchange flows at large scales. Further evidence is needed to link hyporheic exchange flows across scales. This review aims to conceptualize interacting factors at catchment, valley and reach scales that control spatial and temporal variations in hyporheic exchange flows. The implications of these drivers are discussed for each scale, and co-occurrences across scale are highlighted in a case of study. By using a multi-scale perspective, this review connects field observations and modelling studies to identify broad and general patterns of HEF in different catchments. This multi-scale perspective is useful to devise approaches to interpret hyporheic exchange across multiscale heterogeneities, to infer scaling relationships, and to inform watershed management decisions.

scholarly journals The variation in genetic material of a high Alpine catchment reveals (sub)surface exchange

2020 ◽  
Author(s):  
Elvira Maechler ◽  
Natalie Ceperley ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
...  
Keyword(s):  
Genetic Material ◽  
Environmental Dna ◽  
Main Channel ◽  
Hyporheic Exchange ◽  
Stream Network ◽  
Flow Paths ◽  
Surface Exchange ◽  
Hydrologic Processes ◽  
Hydrologic Tracers ◽  
Overbank Flow

<p>In the past years, it has been proposed that stream networks can accumulate genetic material over a given area. Accordingly, a sample of environmental DNA (eDNA) from streamflow at the outlet of a catchment can be used as an indicator of the upstream biodiversity. eDNA’s use in ecological studies is becoming more and more common and it seems reasonable to assume that eDNA might also offer a powerful tool as a hydrologic tracer. However, the original ecological proposition largely simplifies the complexity of any seasonal, diurnal, or spatial variation according to hydrologic flow paths and processes. From a hydrological perspective, this shortcoming is particularly problematic in Alpine headwater catchments, where the combination of snowmelt-dominated summer flow and particularly high climatic and geomorphologic heterogeneity results in hydrologic flow paths that are especially dynamic in space and time. </p><p>We were interested to see if on one hand, eDNA could teach us something new about hydrologic (subsurface) flow paths, and on the other hand, if biodiversity assessment should consider hydrologic variation in detail. To do so, we sampled natural occurring eDNA at 11 points distributed over the 13.4 km<sup>2</sup>, intensively monitored Vallon de Nant (1189-3051 m. a.s.l., Switzerland) between March and September 2017. We chose points corresponding to three different potential microhabitats and flow regimes (main channel, tributary, and spring) likely both inhabited by characteristic organismal communities and of interest for identifying hydrologic flow paths. We found that at moments when streamflow was increasing rapidly, biological richness in upstream points in the main channel and in tributaries was highest contrary to springs, where richness was higher when electrical conductivity was highest.  Thus, the main conclusion from our work is that elevated richness corresponds to moments in time when multiple mechanisms transport additional, probably terrestrial, DNA into water storage or flow compartments. These mechanisms could include overbank flow, stream network expansion, and hyporheic exchange. Our data demonstrates that biodiversity assessments using eDNA do need to consider hydrologic processes and shows that there is a potential future for eDNA among hydrologic tracers.  We will give recommendations in this talk about how to sample eDNA to answer hydrologic questions.</p><p> </p>

scholarly journals Water tracing with environmental DNA in a high-Alpine catchment

2019 ◽  
Author(s):  
Elvira Mächler ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
Bettina Schaefli ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Water Source ◽  
Main Channel ◽  
Hyporheic Exchange ◽  
Multiple Time ◽  
Catchment Scale ◽  
Stream Network ◽  
Overbank Flow ◽  
And Storage ◽  
Biological Richness

Abstract. Alpine streams are particularly valuable for downstream water resources and for ecosystem conservation. However, the details of where and when water is stored and released in the heterogeneous mountain environment are rarely known. The use of physico-chemical flow path tracers is particularly challenging due to the temporary accumulation and storage of water in the form of snow and ice. Alternatively, biological tracers might complement information on flow and storage of water, especially as the different microhabitats in Alpine aquatic systems are inhabited by characteristic organismal communities. In this study, we explored the potential of particles of environmental DNA found in the water (eDNA) to characterize hydrological flow paths and connectivity in an Alpine catchment in Switzerland. Between March and September 2017, we sampled water at multiple time points at 11 sites distributed over the 13.4 km2 Vallon de Nant catchment for genetic species information based on naturally occurring eDNA. The sites correspond to three different water source types and habitats (main channel, tributaries, and springs). Comparison of typical hydrological tracers and eDNA with temporal evolution of streamflow revealed that in the main channel and in the tributaries, the change in streamflow, dq/dt, is strongly correlated with biological richness. In springs, electrical conductivity was found to have a positive but not as strong correlation with biological richness. At the catchment scale, our results show that biological richness as indicated by the diversity detected by eDNA samples. When streamflow is increasing, transport of additional, and probably terrestrial, DNA into water storage or flow compartments is occurring. Such processes include overbank flow, stream network expansion and retraction, and hyporheic exchange. In general, our results highlight the importance of considering the at-site sampling habitat in combination with upstream connected habitats to understand how streams integrate eDNA over a catchment and to interpret spatially distributed eDNA samples, both for hydrological and biodiversity assessments. We identify next steps to be addressed to use eDNA as an independent tracer of Alpine water sources and we provide recommendations for future observation of eDNA in Alpine stream ecosystems.

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