Ecohydraulic modelling of anabranching rivers

In this paper we provide the first quantitative evidence of the spatial complexity of habitat diversity across the flow regime for locally anabranching channels, and their potential increased biodiversity value in comparison to managed single-thread rivers. Ecohydraulic modelling is used to provide evidence for the potential ecological value of anabranching channels. Hydraulic habitat (biotopes) of an anabranched reach of the River Wear at Wolsingham, UK is compared with an adjacent artificially straightened single-thread reach downstream. 2D hydraulic modelling was undertaken across the flow regime. Simulated depth and velocity data were used to calculate Froude number (Fr) index; known to be closely associated with biotope type, allowing biotope maps to be produced for each flow simulation using published Fr limits. The gross morphology of the anabranched reach appears to be controlling flow hydraulics, creating a complex and diverse biotope distribution at low and intermediate flows. This contrasts markedly with the near uniform biotope pattern modelled for the heavily modified single-thread reach. As discharge increases the pattern of biotopes altered to reflect a generally higher energy system, interestingly, however, a number of low energy biotopes were activated through the anabranched reach as new sub-channels became inundated and this process is creating valuable refugia for macroinvertebrates and fish, during times of flood. In contrast, these low energy areas were not seen in the straightened single thread reach. Model results suggest that anabranched channels have a vital role to play in regulating flood energy on river systems and in creating and maintaining hydraulic habitat diversity

A review of assessment methods for river hydromorphology

The work leading to this paper has received funding for the EU’s FP7 under Grant Agreement No. 282656 (REFORM

To plug-in or not to plug-in? Geomorphic analysis of rivers using the River Styles Framework in an era of big data acquisition and automation

n an era of big‐data acquisition and semiautomation of geomorphic river surveys, it is timely to consider how to better integrate this into existing and widely used conceptual frameworks and approaches to analysis. We demonstrate how Stage 1 of the River Styles Framework, which entails identification and interpretation of river character and behavior, patterns and controls, can be used as a “powerboard” into which available, developing and future semiautomated tools and workflows can be plugged (or unplugged). Prospectively, such approaches will increase the efficiency and scope of analyses, providing unprecedented insights into the diversity of rivers and their morphodynamics. We appraise the role of human decision‐making in conducting expert‐manual analyses and interpretations. Genuine integration of big‐data analytics, remote‐sensing based tools for semiautomated river analysis with expert‐manual interpretations including field insights, will be an essential ingredient to fully exploit emerging computational and remote sensing technologies to advance our understanding of river systems, to translate information into knowledge, and raise the standards of practice in river science and management

Indicators of river system hydromorphological character and dynamics: understanding current conditions and guiding sustainable river management

The work leading to this paper received funding from the EU’s FP7 programme under Grant Agreement No. 282656 (REFORM). The Indicators were developed within the context of REFORM deliverable D2.1, therefore all partners involved in this deliverable contributed to some extent to their discussion and development

A palaeoenvironmental study of particle size-specific connectivity- new insights and implications from the West Sussex Rother Catchment, United Kingdom

Connectivity has become an important conceptual and practical framework for understanding and managing sediment transfers across hillslopes, between hillslopes and rivers and between rivers and other compartments along the river corridor (e.g. reservoirs, channel substrate, floodplain). Conventionally, connectivity focuses on the quantity of sediment transferred but here we also consider the size of the finer sediment (typically particles < 500 µm diameter). We examine the role of small rapidly silting reservoirs in the River Rother on storing sediment and disrupting downstream sediment transfers. Spatial and temporal changes in the particle size characteristics of sediment deposited in one of the ponds is explored in detail. Downstream of this pond we collected sediment from the river on nine occasions over 17 months using two sampling methods at two locations; one immediately downstream of the pond and a second ~700 m further downstream but upstream of the confluence with the Rother. Results showed a significant depletion in sand sized particles immediately downstream of the pond but the sand had been recovered from an in-channel source before the river reached the downstream sampling point

Therapeutic Potential of HDL in Cardioprotection and Tissue Repair

Epidemiological studies support a strong association between high-density lipoprotein (HDL) cholesterol levels and heart failure incidence. Experimental evidence from different angles supports the view that low HDL is unlikely an innocent bystander in the development of heart failure. HDL exerts direct cardioprotective effects, which are mediated via its interactions with the myocardium and more specifically with cardiomyocytes. HDL may improve cardiac function in several ways. Firstly, HDL may protect the heart against ischaemia/reperfusion injury resulting in a reduction of infarct size and thus in myocardial salvage. Secondly, HDL can improve cardiac function in the absence of ischaemic heart disease as illustrated by beneficial effects conferred by these lipoproteins in diabetic cardiomyopathy. Thirdly, HDL may improve cardiac function by reducing infarct expansion and by attenuating ventricular remodelling post-myocardial infarction. These different mechanisms are substantiated by in vitro, ex vivo, and in vivo intervention studies that applied treatment with native HDL, treatment with reconstituted HDL, or human apo A-I gene transfer. The effect of human apo A-I gene transfer on infarct expansion and ventricular remodelling post-myocardial infarction illustrates the beneficial effects of HDL on tissue repair. The role of HDL in tissue repair is further underpinned by the potent effects of these lipoproteins on endothelial progenitor cell number, function, and incorporation, which may in particular be relevant under conditions of high endothelial cell turnover. Furthermore, topical HDL therapy enhances cutaneous wound healing in different models. In conclusion, the development of HDL-targeted interventions in these strategically chosen therapeutic areas is supported by a strong clinical rationale and significant preclinical data.status: publishe

A Dynamic, Network Scale Sediment (Dis)Connectivity Model to Reconstruct Historical Sediment Transfer and River Reach Sediment Budgets

Modeling network-scale sediment (dis)connectivity and its response to anthropic pressures provides a baseline understanding of river processes and sediment dynamics that can be used to forecast future hydro-morphological changes in river basins. However, this requires a solid understanding of how a system is currently operating, and how it operated in the past. We present the basin-scale, dynamic sediment connectivity model D-CASCADE, which combines concepts of network modeling with empirical sediment transport formulas to quantify spatiotemporal sediment (dis)connectivity in river networks. D-CASCADE accounts for multiple factors affecting sediment transport, such as spatiotemporal variations in hydrological regime, different sediment grain sizes, sediment entrainment and deposition. Add-ons are included in D-CASCADE to model local changes in river geomorphology driven by sediment-induced variations in features such as channel width. We apply D-CASCADE to the well-documented Bega River catchment, NSW, Australia, where significant geomorphic changes to rivers have occurred post European colonization (after 1850s), including widespread channel erosion and sediment mobilization. The Bega catchment provides a useful case study to test D-CASCADE, as original source data on the historical sediment budget are available. By introducing historic drivers of change in the correct chronological sequence, the D-CASCADE model successfully reproduced the timing and magnitude of major phases of sediment transport and associated channel adjustments over the last two centuries. With this confidence, we then ran the model to test how well it performs at estimating future trajectories of basin-scale sediment transport and sediment budgets at the river reach scale