Improving pan-European hydrological simulation of extreme events through statistical bias correction of RCM-driven climate simulations

In this work we asses the benefits of removing bias in climate forcing data used for hydrological climate change impact assessment at pan-European scale, with emphasis on floods. Climate simulations from the HIRHAM5-ECHAM5 model driven by the SRES-A1B emission scenario are corrected for bias using a histogram equalization method. As target for the bias correction we employ gridded interpolated observations of precipitation, average, minimum, and maximum temperature from the E-OBS data set. Bias removal transfer functions are derived for the control period 1961–1990. These are subsequently used to correct the climate simulations for the control period, and, under the assumption of a stationary error model, for the future time window 2071–2100. Validation against E-OBS climatology in the control period shows that the correction method performs successfully in removing bias in average and extreme statistics relevant for flood simulation over the majority of the European domain in all seasons. This translates into considerably improved simulations with the hydrological model of observed average and extreme river discharges at a majority of 554 validation river stations across Europe. Probabilities of extreme events derived employing extreme value techniques are also more closely reproduced. Results indicate that projections of future flood hazard in Europe based on uncorrected climate simulations, both in terms of their magnitude and recurrence interval, are likely subject to large errors. Notwithstanding the inherent limitations of the large-scale approach used herein, this study strongly advocates the removal of bias in climate simulations prior to their use in hydrological impact assessment

Análisis de sensibilidad con MIKE SHE variando topografía y ET

[ES] Se modeló la hidrología superficial y subterránea de una cuenca media con el código MIKE SHE. Se llevó a cabo un Análisis de Sensibilidad (AS) variando datos de topografía y evapotranspiración (ET), variables importantes para modelar el balance hídrico de una cuenca. Se generaron tres Modelos de Elevación Digital (MED) para preparar igual número de modelos hidrológicos difiriendo sólo en términos de la topografía. Se investigó, mediante la calibración independiente de los modelos hidrológicos, los efectos de los MED en las predicciones y en los parámetros de los modelos. En general, se observó una diferencia razonable entre los datos disponibles de elevación y los MED. Sin embargo, en particular, uno de los métodos de interpolación indujo la presencia significativa de depresiones y vías de desagüe artificiales. Paradójicamente, las predicciones del modelo hidrológico correspondiente resultaron ser las más aceptables. El análisis indicó una dependencia significativa de las prediccionesVázquez, RF.; Feyen, J.; Berlamont, J. (2004). Análisis de sensibilidad con MIKE SHE variando topografía y ET. Ingeniería del agua. 11(3):315-328. https://doi.org/10.4995/ia.2004.2540315328113Chow V. T., Maidment D. R. y Mays L W. (1988). Applied Hydrology. McGraw-Hill international Editions, Singapore, 572pp.DHI, (1998). MIKE-SHE v.5.30 User Guide and Technical Reference Manual, Danish Hydraulic Institute, Copenague, 50pp.Doorenbos J. y Pruitt W. O., (1977). FAO Irrigation and Drainage Paper 24: Crop water requirements, FAO, Roma, 156.Feyen L., Vázquez R. F., Christiaens K., Sels O. y Feyen, J., (2000). Application of a distributed physically-based hydrologic model to a medium size catchment. Hydrology and Earth System Sciences 4, 47-63.Hubrechts L., Vlassak V., Van Criekingen A. y Feyen J. (1997). En publicación interna (48) Handleiding bij AARDEWERK-SISBIS: Bevraginssysteem voor bodemprofielgegevens, bodemoppervlaktegegevens en bodemgeschiktheids-gegevens. Institute for Land and Water Management (K.U.Leuven), Lovaina, 56pp.Jayatilaka C.J., Storm B. y Mudgway, L.B., (1998). Simulation of water flow on irrigation bay scale with MIKE SHE. Journal of Hydrology 208, 108-130.Kristensen K.J. y Jensen S.E. (1975). A model for estimating actual evapotranspiration from potential evapotranspiration, Nordic Hydrology 6, 170-188.Madsen H. (2003). Parameter estimation in distributed hydrological catchment modelling using automatic calibration with multiple objectives. Advances in Water Resources 26, 205-216.Pandey M. D., van Gelder P. H. A. J. M. y Vrijling J. K. (2003). The Use of L-Moments in the Peak Over Threshold Approach for Estimating Extreme Quantiles of Wind Velocity. Memorias de "the European Safety and Reliability Conference 2003", Maastricht, Países Bajos.Quinn P., Beven K.J. y Lamb R. (1995). The ln(a/tanß) index: how to calculate it and how to use it within the TOPMODEL framework. Hydrological Processes 9, 161-182.Refsgaard J.C. y Storm B., (1995). MIKE SHE. En: Singh, V P (ed.), Computer Models of Watershed Hydrology, Capitulo 23, Water Resources Publications, Highlands Ranch, 809-846.Refsgaard J.C. (1997). Parameterisation, calibration and validation of distributed hydrological models. Journal of Hydrology 198, 69-97.Rosbjerg D., Madsen H. y Rasmussen P. F. (1992). Prediction in partial duration series with generalized Pareto-distributed exceedances. Water Resources Research, 28, 3001-3010.Saulnier G.-M., Obled Ch. y Beven, K. (1997). Analytical compensation between DTM grid resolution and effective values of saturated hydraulic conductivity within the TOPMODEL framework. Hydrological Processes 11, 1331-1346.Vázquez R.F., Feyen L., Feyen J. y Refsgaard J.C., (2002). Effect of grid-size on effective parameters and model performance of the MIKE SHE code applied to a medium sized catchment. Hydrological Processes 16, 355-372.Vázquez R.F., (2003). Assessment of the performance of physically based distributed codes simulating medium size hydrological systems. PhD thesis ISBN 90-5682-416-3, Department of Civil Engineering, K. U. Leuven, Lovaina, 335pp.Vázquez R.F. y Feyen J., (2004). Potential Evapotranspiration for the distributed modelling of Belgian basins. Journal of Irrigation and Drainage Engineering ASCE 130, 1-8.Walker J.P. y Willgoose G.R., (1999). On the effect of digital elevation model accuracy on hydrology and geomorphology. Water Resources Research 35, 2259-2268.Xevi E., Christiaens K., Espino A., Sewnandan W., Mallants D., Sorensen H. y Feyen J., (1997). Calibration, Validation and Sensitivity Analysis of the MIKE-SHE Model Using the Neuenkirchen Catchment as Case Study. Water Resources Management 11, 219-239

Muscle Fatigue Analysis Using OpenSim

In this research, attempts are made to conduct concrete muscle fatigue analysis of arbitrary motions on OpenSim, a digital human modeling platform. A plug-in is written on the base of a muscle fatigue model, which makes it possible to calculate the decline of force-output capability of each muscle along time. The plug-in is tested on a three-dimensional, 29 degree-of-freedom human model. Motion data is obtained by motion capturing during an arbitrary running at a speed of 3.96 m/s. Ten muscles are selected for concrete analysis. As a result, the force-output capability of these muscles reduced to 60%-70% after 10 minutes' running, on a general basis. Erector spinae, which loses 39.2% of its maximal capability, is found to be more fatigue-exposed than the others. The influence of subject attributes (fatigability) is evaluated and discussed

Recruitment, augmentation and apoptosis of rat osteoclasts in 1,25-(OH)2D3 response to short-term treatment with 1,25-dihydroxyvitamin D3in vivo

Background Although much is known about the regulation of osteoclast (OC) formation and activity, little is known about OC senescence. In particular, the fate of of OC seen after 1,25-(OH)2D3 administration in vivo is unclear. There is evidence that the normal fate of OC is to undergo apoptosis (programmed cell death). We have investigated the effect of short-term application of high dose 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on OC apoptosis in an experimental rat model. Methods OC recruitment, augmentation and apoptosis was visualised and quantitated by staining histochemically for tartrate resistant acid phosphatase (TRAP), double staining for TRAP/ED1 or TRAP/DAPI, in situ DNA fragmentation end labelling and histomorphometric analysis. Results Short-term treatment with high-dose 1,25-(OH)2D3 increased the recruitment of OC precursors in the bone marrow resulting in a short-lived increase in OC numbers. This was rapidly followed by an increase in the number of apoptotic OC and their subsequent removal. The response of OC to 1,25-(OH)2D3 treatment was dose and site dependent; higher doses producing stronger, more rapid responses and the response in the tibiae being consistently stronger and more rapid than in the vertebrae. Conclusions This study demonstrates that (1) after recruitment, OC are removed from the resorption site by apoptosis (2) the combined use of TRAP and ED1 can be used to identify OC and their precursors in vivo (3) double staining for TRAP and DAPI or in situ DNA fragmentation end labelling can be used to identify apoptotic OC in vivo

Multisectoral partnerships and risk information

Knowing the increasing trends in natural disasters and losses, it is imperative to take action on disaster risks to improve resilience of European societies to natural hazards. The main goal, therefore, of the ENHANCE project is to develop and analyse innovative ways to manage natural hazard risks. The key is to develop new multi-sectoral partnerships (MSPs) that aim at reducing or redistributing risk, and increase resilience of societiesinfo:eu-repo/semantics/publishedVersio

African heritage sites threatened as sea-level rise accelerates

The African coast contains heritage sites of ‘Outstanding Universal Value’ that face increasing risk from anthropogenic climate change. Here, we generated a database of 213 natural and 71 cultural African heritage sites to assess exposure to coastal flooding and erosion under moderate (RCP 4.5) and high (RCP 8.5) greenhouse gas emission scenarios. Currently, 56 sites (20%) are at risk from a 1-in-100-year coastal extreme event, including the iconic ruins of Tipasa (Algeria) and the North Sinai Archaeological Sites Zone (Egypt). By 2050, the number of exposed sites is projected to more than triple, reaching almost 200 sites under high emissions. Emissions mitigation from RCP 8.5 to RCP 4.5 reduces the number of very highly exposed sites by 25%. These findings highlight the urgent need for increased climate change adaptation for heritage sites in Africa, including governance and management approaches, site-specific vulnerability assessments, exposure monitoring, and protection strategies

Uncertainty and Bias in Global to Regional Scale Assessments of Current and Future Coastal Flood Risk

This study provides a literature-based comparative assessment of uncertainties and biases in global to world-regional scale assessments of current and future coastal flood risks, considering mean and extreme sea-level hazards, the propagation of these into the floodplain, people and coastal assets exposed, and their vulnerability. Globally, by far the largest bias is introduced by not considering human adaptation, which can lead to an overestimation of coastal flood risk in 2100 by up to factor 1300. But even when considering adaptation, uncertainties in how coastal societies will adapt to sea-level rise dominate with a factor of up to 27 all other uncertainties. Other large uncertainties that have been quantified globally are associated with socio-economic development (factors 2.3–5.8), digital elevation data (factors 1.2–3.8), ice sheet models (factor 1.6–3.8) and greenhouse gas emissions (factors 1.6–2.1). Local uncertainties that stand out but have not been quantified globally, relate to depth-damage functions, defense failure mechanisms, surge and wave heights in areas affected by tropical cyclones (in particular for large return periods), as well as nearshore interactions between mean sea-levels, storm surges, tides and waves. Advancing the state-of-the-art requires analyzing and reporting more comprehensively on underlying uncertainties, including those in data, methods and adaptation scenarios. Epistemic uncertainties in digital elevation, coastal protection levels and depth-damage functions would be best reduced through open community-based efforts, in which many scholars work together in collecting and validating these data

U.S. IOOS coastal and ocean modeling testbed : inter-model evaluation of tides, waves, and hurricane surge in the Gulf of Mexico

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 118 (2013): 5129–5172, doi:10.1002/jgrc.20376.A Gulf of Mexico performance evaluation and comparison of coastal circulation and wave models was executed through harmonic analyses of tidal simulations, hindcasts of Hurricane Ike (2008) and Rita (2005), and a benchmarking study. Three unstructured coastal circulation models (ADCIRC, FVCOM, and SELFE) validated with similar skill on a new common Gulf scale mesh (ULLR) with identical frictional parameterization and forcing for the tidal validation and hurricane hindcasts. Coupled circulation and wave models, SWAN+ADCIRC and WWMII+SELFE, along with FVCOM loosely coupled with SWAN, also validated with similar skill. NOAA's official operational forecast storm surge model (SLOSH) was implemented on local and Gulf scale meshes with the same wind stress and pressure forcing used by the unstructured models for hindcasts of Ike and Rita. SLOSH's local meshes failed to capture regional processes such as Ike's forerunner and the results from the Gulf scale mesh further suggest shortcomings may be due to a combination of poor mesh resolution, missing internal physics such as tides and nonlinear advection, and SLOSH's internal frictional parameterization. In addition, these models were benchmarked to assess and compare execution speed and scalability for a prototypical operational simulation. It was apparent that a higher number of computational cores are needed for the unstructured models to meet similar operational implementation requirements to SLOSH, and that some of them could benefit from improved parallelization and faster execution speed.This project was supported by NOAA via the U.S. IOOS Office (award: NA10NOS0120063 and NA11NOS0120141

Comparison of weather station and climate reanalysis data for modelling temperature-related mortality

Epidemiological analyses of health risks associated with non-optimal temperature are traditionally based on ground observations from weather stations that offer limited spatial and temporal coverage. Climate reanalysis represents an alternative option that provide complete spatio-temporal exposure coverage, and yet are to be systematically explored for their suitability in assessing temperature-related health risks at a global scale. Here we provide the first comprehensive analysis over multiple regions to assess the suitability of the most recent generation of reanalysis datasets for health impact assessments and evaluate their comparative performance against traditional station-based data. Our findings show that reanalysis temperature from the last ERA5 products generally compare well to station observations, with similar non-optimal temperature-related risk estimates. However, the analysis offers some indication of lower performance in tropical regions, with a likely underestimation of heat-related excess mortality. Reanalysis data represent a valid alternative source of exposure variables in epidemiological analyses of temperature-related risk

The impacts of climate change on river flood risk at the global scale

This paper presents an assessment of the implications of climate change for global river flood risk. It is based on the estimation of flood frequency relationships at a grid resolution of 0.5 × 0.5°, using a global hydrological model with climate scenarios derived from 21 climate models, together with projections of future population. Four indicators of the flood hazard are calculated; change in the magnitude and return period of flood peaks, flood-prone population and cropland exposed to substantial change in flood frequency, and a generalised measure of regional flood risk based on combining frequency curves with generic flood damage functions. Under one climate model, emissions and socioeconomic scenario (HadCM3 and SRES A1b), in 2050 the current 100-year flood would occur at least twice as frequently across 40 % of the globe, approximately 450 million flood-prone people and 430 thousand km2 of flood-prone cropland would be exposed to a doubling of flood frequency, and global flood risk would increase by approximately 187 % over the risk in 2050 in the absence of climate change. There is strong regional variability (most adverse impacts would be in Asia), and considerable variability between climate models. In 2050, the range in increased exposure across 21 climate models under SRES A1b is 31–450 million people and 59 to 430 thousand km2 of cropland, and the change in risk varies between −9 and +376 %. The paper presents impacts by region, and also presents relationships between change in global mean surface temperature and impacts on the global flood hazard. There are a number of caveats with the analysis; it is based on one global hydrological model only, the climate scenarios are constructed using pattern-scaling, and the precise impacts are sensitive to some of the assumptions in the definition and application