Application of airborne LiDAR bathymetry in Norway

New technologies in remote sensing provide opportunities for effectively sampling information on topography and bathymetry for large areas. With Airborne LiDAR Bathymetry (ALB) terrain and also the river bottom (bathymetry) can be measured with high accuracy. In this report we present our contributions to 1) validation, 2) flood risk analysis and mitigation, and 3) river restoration. All rivers could be classified to river types according to Hauer & Pulg (2018) from remote sensing data only. ALB data can be much faster than other surveying or mapping methods and has higher accuracy. Ecological information can be acquired from ALB data in higher resolution than with other methods, and also parameters like grain size and shelter have a high correlation with ALB derivates. The ALB datasets can be used for planning and assessing ecological and flood related questions from the desktop with a strongly reduced requirement for field work compared to data from other data sources, additionally giving a model verification with much higher accuracy and detail degree than other methods. ALB can therefore improve planning safety and speed up planning and modelling process for high- flow, low-flow, morphodynamics and ecological applications. The Lærdal flood case study shows that advances in remote sensing can be used to develop and model nature-based and integrated solutions for improving flood safety and ecological status.Application of airborne LiDAR bathymetry in NorwaypublishedVersio

In situ measurements of fine sediment infiltration (FSI) in gravel-bed rivers with a hydropeaking flow regime

The overpresence of fine sediment and fine sediment infiltration (FSI) in the aquatic environment of rivers are of increasing importance due to their limiting effects on habitat quality and use. The habitats of both macroinvertebrates and fish, especially spawning sites, can be negatively affected. More recently, hydropeaking has been mentioned as a driving factor in fine sediment dynamics and FSI in gravel-bed rivers. The primary aim of the present study was to quantify FSI in the vertical stratigraphy of alpine rivers with hydropeaking flow regimes in order to identify possible differences in FSI between the permanently wetted area (during base and peak flows) and the so-called dewatering areas, which are only inundated during peak flows. Moreover, we assessed whether the discharge ratio between base and peak flow is able to explain the magnitude of FSI. To address these aims, freeze-core samples were taken in eight different alpine river catchments. The results showed significant differences in the vertical stratification of FSI between the permanently wetted area during base flow and the dewatering sites. Surface clogging occurred only in the dewatering areas, with decreasing percentages of fine sediments associated with increasing core depths. In contrast, permanently wetted areas contained little or no fine sediment concentrations on the surface of the river bed. Furthermore, no statistical relationship was observed between the magnitude of hydropeaking and the sampled FSI rate. A repeated survey of FSI in the gravel matrix revealed the importance of de-clogging caused by flooding and the importance of FSI in the aquatic environment, especially in the initial stages of riparian vegetation establishment

Helhetlig tiltaksplan og klimasårbarhetsanalyse for Sokndalsvassdraget

I et tverrfaglig samarbeid som inkluderer ferskvanns- og restaureringsbiologi, klimaforskning, hydrologi og hydraulikk vises at vassdragsmiljøet i Sokndalsvassdraget er påvirket av en rekke fysiske inngrep og forurensing. Etter at forsuring er håndtert ved kalking vurderes finsedimentutslipp fra Sandbekkområdet som hovedpåvirkning. Utslippene har ført til svært lite skjul i elvebunn med reduserte forhold for elvemusling og svært lave fisketettheter. Flomdemping med flomtunell vil medføre virkning på miljøforhold som har blitt undervurdert i tidligere studier. Det er særlig plantevekst og sedimenteringsforhold som vil endres ved flomdemping, men også elvemorfologi vil kunne påvirkes. Miljørisikoen økes betydelig fordi det finnes allerede en storskala og langvarig finsedimentforurensing i vassdraget. Problemvekst av vannplanter og opphoping av sediment vil ved siden av miljøeffekter påvirke landbruk, ev. vannbruk, friluftsliv og kunne føre til lokal oversvømmelsesfare (krypsivproblematikk). Hydraulisk modellering viste at en flomtunell fra Lono i kombinasjon med elverestaurering og sikringstiltak vil kunne være et alternativ som gir lavere kostnader og mindre miljørisiko. Omfang av miljøpåvirkning vil avhenge hvilken type flomdemping som velges, beliggenhet av flomtunell og ved hvilken vannføring flomdemping begynnes. Miljørisiko vil være størst for flomtunnel ved Prestbro, vedvarende finsedimentustlipp og hyppig flomdemping fra 20-års flom og mindre. Det viktigste tiltaket for å avbøte negativ miljøpåvirkning av flomdemping er å stoppe ytterligere finsedimentutslipp fra Sandbekkområdet og skånsom rensing av elvebunn som er påvirket av finsediment derfra. Dette vil kunne flerdoble fisketetthetene som er svært lave i dag. Deretter vil prioritering av miljøtiltak være avhengig av valgt scenario og omfang av flomdemping. Demping av mindre flommer (Q50) samt stopp av finsedimentustlipp og rensing av elvebunn fra Sandbekk og nedover vil kunne sikre miljøforhold og fiskeproduksjon samt bedre habitatet for elvemusling i forhold til 2020. Et worst case scenario for miljøet vil være at finsedimentpåvirkningen fra Sandbekk fortsetter og det samtidig innføres en sterk flomdemping der også mindre flommer under Q20 dempes fra Prestbro. I så fall må det regnes med en sterkt redusert miljøtilstand med fare for at elvemusling forsvinner og laks- og ørretproduksjon reduseres sterkt. I tillegg må det regnes med problemvekst av planter inkludert krypsiv og opphoping av sedimenter med medfølgende konsekvenser for miljø, landbruk, friluftsliv og lokal oversvømmelsesfare nedenfor Prestbro.Helhetlig tiltaksplan og klimasårbarhetsanalyse for SokndalsvassdragetpublishedVersio

Increased CSF aquaporin-4, and interleukin-6 levels in dogs with idiopathic communicating internal hydrocephalus and a decrease after ventriculo-peritoneal shunting

Background: Studies in animal models, in which internal hydrocephalus has been induced by obstructing the cerebrospinal fluid pathways, have documented an up-regulation of the concentrations of aquaporin-4 (AQP4) in the brain. In this study, the concentrations of aquaporin-1 (AQP1), AQP1, AQP4 and interleukin-6 (IL-6) were determined in the CSF of dogs with idiopathic communicating hydrocephalus before and after the reduction of intraventricular volume following ventriculo-peritoneal shunt (VP-shunt) treatment. Results: The concentrations of AQP4 and IL-6 were increased in the cerebrospinal fluid of dogs with hydrocephalus compared to controls. Both parameters significantly decreased after surgical treatment, accompanied by decrease of ventricular size and the clinical recovery of the dogs. AQP1 was not detectable in CSF. Conclusions: Brain AQP4 up-regulation might be a compensatory response in dogs with hydrocephalus. Future determination of AQP4 at the mRNA and protein level in brain tissue is warranted to substantiate this hypothesis

Real-life experience with the specific reversal agent idarucizumab for the management of emergency situations in dabigatran-treated patients : a series of 11 cases

Non-vitamin K antagonist oral anticoagulants (NOACs) have a favorable benefit-risk profile compared with vitamin K antagonists. However, the lack of specific reversal agents has made the management of some patients receiving long-term treatment with NOACs problematic in emergency situations such as major bleeding events or urgent procedures. Idarucizumab, a fully humanized Fab antibody fragment that binds specifically and with high affinity to dabigatran, was recently approved for use in adult patients treated with dabigatran when rapid reversal of its anticoagulant effect is required. Clinical experience with idarucizumab is currently limited. We report 11 real-life clinical cases in which idarucizumab was used after multidisciplinary consultation in a variety of emergency situations including severe postoperative bleeding, emergency high-bleeding-risk surgery (hip/spine surgery and neurosurgery), invasive diagnostic testing (lumbar puncture), intracranial bleeding (pre-pontine subarachnoid hemorrhage and lobar intracerebral hemorrhage) and thrombolysis with recombinant tissue plasminogen activator for acute ischemic stroke. This case series illustrates the role of idarucizumab in improving patient safety in rare emergency situations requiring rapid reversal of the anticoagulant effect of dabigatran, while highlighting the importance of information and education about the availability and appropriate use of this recently approved specific reversal agent

Effects of hydropeaking on drift, stranding and community composition of macroinvertebrates : a field experimental approach in three regulated Swiss rivers

Hydropeaking operation leads to fluctuations in wetted area between base and peak flow and increases discharge-related hydraulic forces (e.g. flow velocity). These processes promote macroinvertebrate drift and stranding, often affecting benthic abundance and biomass. Our field experimental study—conducted in three hydropeakingregulated Swiss rivers—aimed to quantify (a) the short-term effects of the combined increase in flow amplitude and up-ramping rate based on macroinvertebrate drift and stranding, as well as (b) long-term effects based on the established community composition. Hydropeaking led to increased macroinvertebrate drift compared to base flow and to unaffected residual flow reaches. Moreover, stranding of macroinvertebrates was positively related to drift, especially during the up-ramping phase. Flow velocity and up-ramping rate were identified as major determinants for macroinvertebrate drift, while flow ratio and down-ramping rate for stranding. Particularly high sensitivity towards hydropeaking was found for Limnephilidae, whereas Heptageniidae seemed to be resistant in respect to short- and long-term hydropeaking effects. In the longterm, hydropeaking did not considerably reduce benthic density of most taxa, especially of some highly resistant and resilient taxa such as Chironomidae and Baetidae, which dominated the community composition even though they showed comparably high drift and stranding responses. Therefore, we argue that high drift and/or stranding, especially of individual-rich taxa, does not necessarily indicate strong hydropeaking sensitivity. Finally, our results demonstrate the necessity to consider the differences in river-specific morphological complexity and hydropeaking intensity, since these factors strongly influence the community composition and short-term drift and stranding response of macroinvertebrates to hydropower pressure