scholarly journals Microphysical and Polarimetric Radar Signatures of an Epic Flood Event in Southern China

2020 ◽  
Vol 12 (17) ◽  
pp. 2772 ◽  
Author(s):  
Yu Ma ◽  
Haonan Chen ◽  
Guangheng Ni ◽  
V. Chandrasekar ◽  
Yabin Gou ◽  
...  
Keyword(s):  
Large Scale ◽  
Extreme Event ◽  
Southern China ◽  
Critical Role ◽  
River Estuary ◽  
Heavy Rainfall Event ◽  
Management Decision ◽  
Polarimetric Radar ◽  
Extreme Rain ◽  
Radar Signatures

An extremely heavy rainfall event hit Guangdong province, China, from 27 August to 1 September 2018. There were two different extreme rain regions, respectively, at the Pearl River estuary and eastern Guangdong, and a record-breaking daily precipitation of 1056.7 mm was observed at Gaotan station on 30 August. This paper utilizes a suite of observations from soundings, a gauge network, disdrometers, and polarimetric radars to gain insights to the two rainfall centers. The large-scale meteorological forcing, rainfall patterns, and microphysical processes, as well as radar-based precipitation signatures are investigated. It is concluded that a west-moving monsoon depression played a critical role in sustaining the moisture supply to the two extreme rain regions, and the combined orographic enhancement further contributed to the torrential rainfall over Gaotan station. The raindrop size distributions (DSD) observed at Zhuhai and Huidong stations, as well as the observed polarimetric radar signatures indicate that the rainfall at Doumen region was characterized by larger raindrops but a lower number concentration compared with that at Gaotan region. In addition, the dual-polarization radars are used to quantify precipitation intensity during this extreme event, providing timely information for flood warning and emergency management decision-making.

Diurnal Variations of Low-Level Winds and Precipitation Response to Large-Scale Circulations during a Heavy Rainfall Event

2019 ◽  
Vol 147 (11) ◽  
pp. 3981-4004 ◽  
Author(s):  
Wenxin Zeng ◽  
Guixing Chen ◽  
Yu Du ◽  
Zhiping Wen
Keyword(s):  
Heavy Rainfall ◽  
Large Scale ◽  
Southern China ◽  
Western Pacific Subtropical High ◽  
Central China ◽  
Subtropical High ◽  
Heavy Rainfall Event ◽  
Inertial Oscillation ◽  
Atmospheric Conditions ◽  
Low Level

Abstract A succession of MCSs developed during the last week of October 2016 and produced extreme heavy rainfall in central China. The event underwent an evident shift from a mei-yu-like warm scenario to an autumn cold scenario. Diurnal cycles of rainfall and low-level winds may be modulated by the shifting of large-scale atmospheric conditions. We conducted observational analyses and numerical experiments to examine how large-scale circulations influenced rainfall systems through diurnally varying processes. The results show that, in the first half (warm) period of the event, intense rainfall mostly occurred in eastern-central China with an early morning peak. It was closely related to a nocturnal southwesterly low-level jet (NLLJ) on the flank of the western Pacific subtropical high. The NLLJ formed near midnight in southern China where ageostrophic wind rotated clockwise due to Blackadar’s inertial oscillation. The NLLJ extended downstream to central China during the predawn hours due to the horizontal advection of momentum. Both the formation and extension of the NLLJ were supported by an enhanced subtropical high that provided relatively warm conditions with surface heating for boundary layer inertial oscillation and strong background southwesterly winds for momentum transport. The NLLJ induced MCSs at its northern terminus where the low-level ascent, moisture flux convergence, and convective instability were enhanced during the predawn hours. In the second half period with an intrusion of cold air, the diurnal amplitude of low-level winds became small under relatively cold and cloudy conditions. Moderate rainfall tended to occur in western-central China with a peak after midnight, most likely due to frontogenetic processes, upslope lifting, and nighttime cloud-top cooling.

Analysis of Flood Inundation in Ungauged Mountainous River Basins: A Case Study of an Extreme Rain Event on 5–6 July 2017 in Northern Kyushu, Japan

2018 ◽  
Vol 13 (5) ◽  
pp. 860-872 ◽  
Author(s):  
Shakti P. C. ◽  
◽  
Tsuyoshi Nakatani ◽  
Ryohei Misumi
Keyword(s):  
Extreme Event ◽  
River Basins ◽  
Heavy Rainfall Event ◽  
Rain Event ◽  
Flood Inundation ◽  
Geospatial Information ◽  
Mountainous Regions ◽  
Flood Depth ◽  
Extreme Rain ◽  
Mountainous River

The heavy rainfall event that occurred on 5–6 July 2017 in Northern Kyushu, Japan, caused extensive flooding across several mountainous river basins and resulted in fatalities and extensive damage to infrastructure along those rivers. For the periods before and during the extreme event, there are no hydrological observations for many of the flooded river basins, most of which are small and located in mountainous regions. We used the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model, a physically based model, to acquire more detailed information about the hydrological processes in the flood-affected ungauged mountain basins. We calibrated the GSSHA model using data from an adjacent gauged river basin, and then applied it to several small ungauged basins without changing the parameters of the model. We simulated the gridded flow and generated a map of the possible maximum flood depth across the basins. By comparing the extent of flood-affected areas from the model with data of the Japanese Geospatial Information Authority (GSI), we found that the maximum flood inundation areas of the river networks estimated by the GSSHA model are sometimes less than those estimated by the GSI, as the influence of landslides and erosion was not considered in the modeling. The model accuracy could be improved by taking these factors into account, although this task would be challenging. The results indicated that simulations of flood inundation in ungauged mountain river basins could contribute to disaster management during extreme rain events.

Large-scale compound flood mapping with deep learning and data fusion techniques

2021 ◽  
Author(s):  
David F. Muñoz ◽  
Paul Muñoz ◽  
Hamed Moftakhari ◽  
Hamid Moradkhani
Keyword(s):  
Deep Learning ◽  
Data Fusion ◽  
Large Scale ◽  
Extreme Event ◽  
Atlantic Coast ◽  
River Estuary ◽  
Flood Mapping ◽  
Hydrodynamic Models ◽  
Synthetic Aperture Radar Data ◽  
Flood Maps

<p>Compound flooding (CF), as a result oceanic, hydrological, meteorological and anthropogenic processes, is an extreme event that threatens life and assets of people living in low-lying areas worldwide. Large-scale CF is often studied with hydrodynamic models that combine either successive or concurrent processes to simulate flood dynamics. In recent years, convolutional neural networks (CNNs) and data fusion (DF) techniques have emerged as feasible and simple alternatives for post-flood mapping when compared to complex modeling. Yet, both techniques have not been explored for large-scale CF mapping. Here, we evaluate the performance of a CNN & DF framework for generating CF maps driven by Hurricane Matthew that hit the southeast Atlantic coast of the U.S. in October, 2016. The framework fuses multispectral imagery (Landsat ARD), dual-polarized synthetic aperture radar data (SAR) and coastal digital elevation maps (DEMs) to generate flood maps of moderate (30 m) spatial resolution. We first train/validate the CNN & DF framework with official land cover maps (C-CAP) as well as flood maps obtained from a calibrated Delft3D-FM model of Savannah River estuary in Georgia, and then evaluate the framework in the southeast Atlantic coast. The highest overall accuracy (97%) and f1-score for permanent/flood water classes (99/100%) are achieved when ARD, SAR and DEM datasets are readily available and adequately fused. Moreover, the resulting CF maps agree well (80%) with hindcast surge and flood guidance maps of the Coastal Emergency Risk Assessment (CERA) web mapper. We also evaluate the framework with different DF alternatives and highlight its usefulness for large-scale compound flood hazard assessments and a thorough calibration of hydrodynamic models. Future work is envisioned toward a comprehensive CNN & DF framework that provides not only accurate large-scale flood extent maps, but also inundation depth based on both deep learning and multi-source data fusion.</p>

Nursing professionals’ attitudes toward use of physical restraints in Styrian nursing homes Austria

Pflege ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 57-63
Author(s):  
Hannes Mayerl ◽  
Tanja Trummer ◽  
Erwin Stolz ◽  
Éva Rásky ◽  
Wolfgang Freidl
Keyword(s):  
Nursing Homes ◽  
Large Scale ◽  
Critical Role ◽  
Physical Restraint ◽  
Care Practice ◽  
Physical Restraints ◽  
Convenience Sample ◽  
Restraint Use ◽  
Positive Attitudes ◽  
Nursing Professionals

Abstract. Background: Given that nursing staff play a critical role in the decision regarding use of physical restraints, research has examined nursing professionals’ attitudes toward this practice. Aim: Since nursing professionals’ views on physical restraint use have not yet been examined in Austria to date, we aimed to explore nursing professionals’ attitudes concerning use of physical restraints in nursing homes of Styria (Austria). Method: Data were collected from a convenience sample of nursing professionals (N = 355) within 19 Styrian nursing homes, based on a cross-sectional study design. Attitudes toward the practice of restraint use were assessed by means of the Maastricht Attitude Questionnaire in the German version. Results: The overall results showed rather positive attitudes toward the use of physical restraints, yet the findings regarding the sub-dimensions of the questionnaire were mixed. Although nursing professionals tended to deny “good reasons” for using physical restraints, they evaluated the consequences of physical restraint use rather positive and considered restraint use as an appropriate health care practice. Nursing professionals’ views regarding the consequences of using specific physical restraints further showed that belts were considered as the most restricting and discomforting devices. Conclusions: Overall, Austrian nursing professionals seemed to hold more positive attitudes toward the use of physical restraints than counterparts in other Western European countries. Future nationwide large-scale surveys will be needed to confirm our findings.

scholarly journals STEM-20. A CANCER STEM CELL-SELECTIVE APOPTOSIS-INDUCING SMALL MOLECULE FOR THE TREATMENT OF GBM

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii200-ii200
Author(s):  
Stephen Skirboll ◽  
Natasha Lucki ◽  
Genaro Villa ◽  
Naja Vergani ◽  
Michael Bollong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Small Molecules ◽  
Small Molecule ◽  
Large Scale ◽  
Critical Role ◽  
Tumor Formation ◽  
Cell Type ◽  
Caspase 1 ◽  
Activation Assay

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is the most aggressive form of primary brain cancer. A subpopulation of multipotent cells termed GBM cancer stem cells (CSCs) play a critical role in tumor initiation and maintenance, drug resistance, and recurrence following surgery. New therapeutic strategies for the treatment of GBM have recently focused on targeting CSCs. Here we have used an unbiased large-scale screening approach to identify drug-like small molecules that induce apoptosis in GBM CSCs in a cell type-selective manner. METHODS A luciferase-based survival assay of patient-derived GBM CSC lines was established to perform a large-scale screen of ∼one million drug-like small molecules with the goal of identifying novel compounds that are selectively toxic to chemoresistant GBM CSCs. Compounds found to kill GBM CSC lines as compared to control cell types were further characterized. A caspase activation assay was used to evaluate the mechanism of induced cell death. A xenograft animal model using patient-derived GBM CSCs was employed to test the leading candidate for suppression of in vivo tumor formation. RESULTS We identified a small molecule, termed RIPGBM, from the cell-based chemical screen that induces apoptosis in primary patient-derived GBM CSC cultures. The cell type-dependent selectivity of RIPGBM appears to arise at least in part from redox-dependent formation of a proapoptotic derivative, termed cRIPGBM, in GBM CSCs. cRIPGBM induces caspase 1-dependent apoptosis by binding to receptor-interacting protein kinase 2 (RIPK2) and acting as a molecular switch, which reduces the formation of a prosurvival RIPK2/TAK1 complex and increases the formation of a proapoptotic RIPK2/caspase 1 complex. In an intracranial GBM xenograft mouse model, RIPGBM was found to significantly suppress tumor formation. CONCLUSIONS Our chemical genetics-based approach has identified a small molecule drug candidate and a potential drug target that selectively targets cancer stem cells and provides an approach for the treatment of GBMs.

scholarly journals Complex Network Modelling of Origin–Destination Commuting Flows for the COVID-19 Epidemic Spread Analysis in Italian Lombardy Region

2021 ◽  
Vol 11 (10) ◽  
pp. 4381
Author(s):  
Angela Lombardi ◽  
Nicola Amoroso ◽  
Alfonso Monaco ◽  
Sabina Tangaro ◽  
Roberto Bellotti
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Critical Role ◽  
Potential Contribution ◽  
Epidemic Spread ◽  
Network Modelling ◽  
Lombardy Region ◽  
Commuting Flows ◽  
Dynamic Growth ◽  
Spread Analysis

Currently the whole world is affected by the COVID-19 disease. Italy was the first country to be seriously affected in Europe, where the first COVID-19 outbreak was localized in the Lombardy region. The further spreading of the cases led to the lockdown of the most affected regions in northern Italy and then the entire country. In this work we investigated an epidemic spread scenario in the Lombardy region by using the origin–destination matrix with information about the commuting flows among 1450 urban areas within the region. We performed a large-scale simulation-based modeling of the epidemic spread over the networks related to three main motivations, i.e., work, study and occasional transfers to quantify the potential contribution of each category of travellers to the spread of the epidemic process. Our findings outline that the three networks are characterised by different weight dynamic growth rates and that the network “work” has a critical role in the diffusion phenomenon showing the greatest contribution to the epidemic spread.

A preliminary study on sediment records of possible typhoon in the northern South China Sea during the past 6500 yr

The Holocene ◽  
2021 ◽  
pp. 095968362110032
Author(s):  
Pingyuan Li ◽  
Mingkun Li ◽  
Huayang Gan ◽  
Zhen Xia
Keyword(s):  
South China Sea ◽  
South China ◽  
Southern China ◽  
Northern South China Sea ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Human Beings ◽  
China Sea ◽  
The Pearl River ◽  
China Coast

Typhoon is an important meteorological phenomenon that affects the living and development of human beings on the southern China coast. However, there is still lack of clarity in the paleo-typhoon history and its influence on the evolution of the ancient human settlement environment since the mid-Holocene. Here, we identify six typhoon-like deposits from a core retrieved from the northern South China Sea shelf, close to the Pearl River Estuary, based on accelerated mass spectrometry 14C dating, grain size, and geochemistry. The sand fractions, CaO, Sr, SiO2/TiO2, and SiO2/Al2O3 were used to indicate the typhoon-like deposits. Results show that the ages with high-frequency typhoons are present ~200–300 cal yr BP, ~800–1000 cal yr BP, ~1500–1700 cal yr BP, ~2000–2100 cal yr BP, ~2400–2500 cal yr BP, and ~2700–3000 cal yr BP. Our results are comparable to the records from adjacent regions. Significantly, the vast tides occurred in the duration of ~2700–3000 cal yr BP in southern China, which probably caused the ancestors’ migration to the inland. Further studies are needed to deeply study the paleo-typhoon history in the southern China coast to verify our results.

Mineral Exploration using CSAMT data: Application to Longmen region metallogenic belt, Guangdong Province, China

Geophysics ◽  
2013 ◽  
Vol 78 (3) ◽  
pp. B111-B119 ◽  
Author(s):  
Xiangyun Hu ◽  
Ronghua Peng ◽  
Guiju Wu ◽  
Weiping Wang ◽  
Guangpu Huo ◽  
...  
Keyword(s):  
Large Scale ◽  
Southern China ◽  
Mineral Exploration ◽  
Geochemical Data ◽  
Data Application ◽  
Metallogenic Belt ◽  
Fe Content ◽  
Geophysical Surveys ◽  
Occam’S Inversion ◽  
Integrated Interpretation

A controlled-source audio-frequency magnetotelluric (CSAMT) survey has been carried out to investigate potential iron (Fe) and polymetallic (Pb-Zn-Cu) deposits in Longmen region, which is one of the main metallogenic belts in southern China. Conducting geophysical surveys in this area is quite difficult due to mountainous terrain, dense forest, and thick vegetation cover. A total of 560 CSAMT soundings were recorded along twelve surveying lines. Two-dimensional Occam’s inversion scheme was used to interpret these CSAMT data. The resulting electric resistivity models showed that three large-scale highly conductive bodies exist within the surveying area. By integrated interpretation combined with available geologic, geophysical, and geochemical data in this area, three prospective mineral deposits were demarcated. Based on the CSAMT results, a borehole penetrating approximately 250-m depth was drilled at the location of 470 m to the northwest end of line 06, defined with a massive pyrite from the depth of 52–235 m with 7%–16% Fe content, as well as locally high-grade Pb-Zn- and Ag-Ti-bearing ores.

scholarly journals Mid-Holocene variability of the East Asian monsoon based on bulk organic δ13C and C/N records from the Pearl River estuary, southern China

The Holocene ◽  
2011 ◽  
Vol 22 (6) ◽  
pp. 705-715 ◽  
Author(s):  
Fengling Yu ◽  
Yongqiang Zong ◽  
Jeremy M Lloyd ◽  
Melanie J Leng ◽  
Adam D Switzer ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Southern China ◽  
East Asian ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
The Pearl River Estuary ◽  
The Pearl River
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