From China’s Heavy Precipitation in 2020 to a “Glocal” Hydrometeorological Solution for Flood Risk Prediction     

Huan WU  Xiaomeng LI  Guy J.-P.SCHUMANN  Lorenzo ALFIERI  Yun CHEN  Hui XU  Zhifang WU  Hong LU  Yamin HU  Qiang ZHU  Zhijun HUANG  Weitian CHEN  Ying HU 《大气科学进展》2021,38(1):1-7

The prolonged mei-yu/baiu system with anomalous precipitation in the year 2020 has swollen many rivers and lakes,caused flash flooding,urban flooding and landslides,and consistently wreaked havoc across large swathes of China,particularly in the Yangtze River basin.Significant precipitation and flooding anomalies have already been seen in magnitude and extension so far this year,which have been exerting much higher pressure on emergency responses in flood control and mitigation than in other years,even though a rainy season with multiple ongoing serious flood events in different provinces is not that uncommon in China.Instead of delving into the causes of the uniqueness of this year’s extreme precipitation-flooding situation,which certainly warrants in-depth exploration,in this article we provide a short view toward a more general hydrometeorological solution to this annual nationwide problem.A“glocal”(global to local)hydrometeorological solution for floods(GHS-F)is considered to be critical for better preparedness,mitigation,and management of different types of significant precipitation-caused flooding,which happen extensively almost every year in many countries such as China,India and the United States.Such a GHS-F model is necessary from both scientific and operational perspectives,with the strength in providing spatially consistent flood definitions and spatially distributed flood risk classification considering the heterogeneity in vulnerability and resilience across the entire domain.Priorities in the development of such a GHS-F are suggested,emphasizing the user’s requirements and needs according to practical experiences with various flood response agencies.  相似文献   

Nonequilibrium Processes in the Solar Corona,Transition Region,Flares, and Solar Wind <Emphasis Type="Italic">(Invited Review)</Emphasis>     

Jaroslav Dudík  Elena Dzifčáková  Nicole Meyer-Vernet  Giulio Del Zanna  Peter R. Young  Alessandra Giunta  Barbara Sylwester  Janusz Sylwester  Mitsuo Oka  Helen E. Mason  Christian Vocks  Lorenzo Matteini  Säm Krucker  David R. Williams  Šimon Mackovjak 《Solar physics》2017,292(8):100

We review the presence and signatures of the non-equilibrium processes, both non-Maxwellian distributions and non-equilibrium ionization, in the solar transition region, corona, solar wind, and flares. Basic properties of the non-Maxwellian distributions are described together with their influence on the heat flux as well as on the rates of individual collisional processes and the resulting optically thin synthetic spectra. Constraints on the presence of high-energy electrons from observations are reviewed, including positive detection of non-Maxwellian distributions in the solar corona, transition region, flares, and wind. Occurrence of non-equilibrium ionization is reviewed as well, especially in connection to hydrodynamic and generalized collisional-radiative modeling. Predicted spectroscopic signatures of non-equilibrium ionization depending on the assumed plasma conditions are summarized. Finally, we discuss the future remote-sensing instrumentation that can be used for the detection of these non-equilibrium phenomena in various spectral ranges.  相似文献   

Structure and distribution of the benthic macrofauna on a Northwest African sandy beach close to a freshwater river discharge     

Abdellatif Chaouti  Isabella Colombini  Mario Fallaci  Elena Gagnarli  Lorenzo Chelazzi  & Abdellatif Bayed 《Marine Ecology》2008,29(S1):99-107

The effects of the freshwater discharge of the Oued Sebou River on the macroinfauna, was studied on the sandy beach of Mehdia through the analysis of the abiotic parameters and of the macrozoobenthos. In autumn 2002 and spring 2003, three beach sites, each with two transects, localized at 50, 3500 and 5720 m from the river mouth respectively, were studied. Positive correlations were recorded for beach slope and pH whereas negative ones were obtained for organic matter content and salinity at increasing distances from the river mouth. Significant differences between beach sites and seasons occurred for median grain size, organic matter content and pH. For each beach site, mean macroinfauna abundance varied between 30 and 100 ind.·m⁻² and in spring there was a significant correlation between this parameter and the increasing distance from the river mouth. No significant correlation was instead found between species richness and the increasing distance, although the farthest beach site from the mouth had the highest number of species during both seasons. The results indicated the importance of organic matter content and salinity for the macrofaunal abundance whereas the diversity indices were more affected by beach slope and grain size. The results showed that there was no clear spatial trend in compound indices of the macrofauna across the sampled sites and the influence of the river discharge of Sebou River did not seem to be significant and consistent on the macrobenthos of this mesotidal shore. Comparison with microtidal shores revealed the influence of the tidal excursion and swell characteristics on the response of the benthic structures of sandy beaches to discharges of freshwater.  相似文献   

The impact of the new Earth gravity models on the measurement of the Lense–Thirring effect with a new satellite     

Lorenzo Iorio   《New Astronomy》2005,10(8):616-635

In this paper we investigate the opportunities offered by the new Earth gravity models from the dedicated CHAMP and, especially, GRACE missions to the project of measuring the general relativistic Lense–Thirring effect with a new Earth’s artificial satellite. It turns out that it would be possible to abandon the stringent, and expensive, requirements on the orbital geometry of the originally prosed LARES mission (same semimajor axis a = 12,270 km of the existing LAGEOS and inclination i = 70°) by inserting the new spacecraft in a relatively low, and cheaper, orbit (a = 7500–8000 km, i  70°) and suitably combining its node Ω with those of LAGEOS and LAGEOS II in order to cancel out the first two even zonal harmonic coefficients of the multipolar expansion of the terrestrial gravitational potential J₂, J₄ along with their temporal variations , . The total systematic error due to the mismodelling in the remaining even zonal harmonics would amount to 1% and would be insensitive to departures of the inclination from the originally proposed value of many degrees. No semisecular long-period perturbations would be introduced because the period of the node, which is also the period of the solar K₁ tidal perturbation, would amount to 10² days. Since the coefficient of the node of the new satellite would be smaller than 0.1 for such low altitudes, the impact of the non-gravitational perturbations of it on the proposed combination would be negligible. Then, a particular financial and technological effort for suitably building the satellite in order to minimize the non-conservative accelerations would be unnecessary.  相似文献   

A Refinement of the McMillen (1988) Recursive Digital Filter for the Analysis of Atmospheric Turbulence     

Marco Falocchi  Lorenzo Giovannini  Massimiliano de Franceschi  Dino Zardi 《Boundary-Layer Meteorology》2018,168(3):517-523

We present a refinement of the recursive digital filter proposed by McMillen (Boundary-Layer Meteorol 43:231–245, 1988), for separating surface-layer turbulence from low-frequency fluctuations affecting the mean flow, especially over complex terrain. In fact, a straightforward application of the filter causes both an amplitude attenuation and a forward phase shift in the filtered signal. As a consequence turbulence fluctuations, evaluated as the difference between the original series and the filtered one, as well as higher-order moments calculated from them, may be affected by serious inaccuracies. The new algorithm (i) produces a rigorous zero-phase filter, (ii) restores the amplitude of the low-frequency signal, and (iii) corrects all filter-induced signal distortions.  相似文献   

Interannual and regional variability in distribution and ecology of juvenile pollock and their prey in frontal structures of the Bering Sea     

Richard D. Brodeur  Matthew T. Wilson  Lorenzo Ciannelli  Miriam Doyle  Jeffrey M. Napp 《Deep Sea Research Part II: Topical Studies in Oceanography》2002,49(26)

The distribution, size, length-specific weight, growth, and feeding of age-0 walleye pollock (Theragra chalcogramma) were examined along with their prey distribution patterns in two contrasting transects over a 4-year period (1994–1997) in relation to biophysical properties of frontal regions around the Pribilof Islands, Bering Sea. There were significant interannual differences in catch of age-0 pollock, but transect and habitat differences (inshore vs. front vs. offshore) were not significant for either catch or size of pollock. There were significant variations in length-specific weight and growth of pollock, but the trends were inconsistent. Copepods dominated the zooplankton biomass in all habitats and years; there were no consistent differences in the densities of the dominant zooplankton taxa among the habitats. There were, however, strong habitat and transect differences in juvenile pollock diet, particularly for the larger and presumably rarer prey taxa (euphausiids, chaetognaths, fish). We did not find any evidence that occupying a particular habitat was beneficial to young pollock, although other factors (e.g. bioenergetic advantage and predation refuge) that we did not examine here could have been more variable and critical to pollock survival. In a physically dynamic system such as the Pribilof Islands, age-0 pollock may need to continuously search for optimal conditions of high prey availability and low predation pressure.  相似文献   

Daily egg production of anchovy in European waters   总被引：7，自引：1，他引：7  

Somarakis  Stylianos; Palomera  Isabel; Garcia  Alberto; Quintanilla  Luis; Koutsikopoulos  Constantin; Uriarte  Andres; Motos  Lorenzo 《ICES Journal of Marine Science》2004,61(6):944-958

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Community structure of fishes in Cabo Pulmo Reef, Gulf of California     

Lorenzo Alvarez-Filip  Héctor Reyes-Bonilla  & Luis E. Calderon-Aguilera 《Marine Ecology》2006,27(3):253-262

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Flood hazards at ford stream crossings on ephemeral channels (south‐east coast of Spain)          下载免费PDF全文

Carmelo Conesa‐García  Rafael García‐Lorenzo  Pedro Pérez‐Cutillas 《水文研究》2017,31(3):731-749

Most road‐stream crossings over ephemeral channels are vulnerable to extreme hydrologic events. Ford stream crossings (FSCs) are usually dangerous for the road traffic during periods of high flow, in particular under flash flood conditions. The present paper analyzes the flood hazards on the Mediterranean coast in the Region of Murcia (south‐east Spain), affecting this type of road‐stream crossing over dry channels, according to hydraulic variables and bedload transport rates estimated for discharges at bankfull and flood‐prone stages. Under such conditions, the safety of people and vehicles was obtained using numerical models, developed by previous researchers; in particular, water levels and flow velocities across ford reaches were compared with different trend curves between water depths and corresponding critical velocities for children and adults, and for various prototype vehicles. Specifically, two approaches to assess this type of hazards were proposed: a specific Hydraulic Hazard Index and an algorithm for estimating the flood hazard from criteria of bed stability and bedload transport capacity (Flood Hazard at Fords, FHF). In addition, different exposure levels were established, using a Flood Vulnerability Index, based on the FHF, the road category, and the annual average daily traffic. The FHF model gave the best results with regard to the magnitude of the damage observed in recent flash floods for flow stages similar to those simulated. According to the danger thresholds established for this index, half‐bankfull flows represent here a high risk: 27.3% of FSCs for mini‐cars and 18.2% for large cars. At bankfull, the FHF exhibits very high values for mini‐cars (77.3% of FSCs) and for large passenger vehicles (50% of FSCs), while at the floodprone stage, extreme FHF values are reached for all kinds of vehicles at most of the ford crossings.  相似文献   

Evaluating the effectiveness of road‐crossing drainage culverts in ephemeral streams     

C. Conesa‐García  R. García‐Lorenzo 《水文研究》2013,27(12):1781-1796

The present study proposes a method for evaluating the effectiveness of road‐crossing drainage culverts in ephemeral streams. This approach is focused on estimating the culvert capacity in road–stream crossings and the probable runoff generated on the road from hydrological thresholds associated with hydromorphological criteria. In particular, discharges at bankfull and flood‐prone stages have been used in combination with 2.5 and 100‐year peak discharges. Different hydraulic variables have been considered for calculating the discharge through culverts under these conditions (e.g. tailwater and headwater depth, inlet control, pipe roughness, pipe cross‐area and slope, pipe outlet velocity, critical water depth, and flow rate over the road). Geomorphological factors such as bed stability, bed load transport, and channel roughness have also been considered because of their potential for obstructing the drains in this type of channel. In addition, a potential obstruction index (PI_OBSTR) has been calculated, as a dependent parameter of the obstacle index (I_OBST) and the potential build‐up of coarse sediments (PB_CS). The study has been carried out on the Mediterranean coast in the region of Murcia (Spain), where there are numerous examples of road–stream crossings equipped with culverts in ephemeral channels that could cause highly dangerous situations for road traffic. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献