scholarly journals Csapadékszélsőségek változása Európa déli alföldi régióiban az 1951–2019 időszakban

2021 ◽  
Vol 16 (4) ◽  
pp. 85-101
Author(s):  
Alexandra Berényi ◽  
◽  
Rita Pongrácz ◽  
Judit Bartholy ◽  
◽  
...  

The aim of our study is to analyse the spatial patterns and temporal trends of average and extreme precipitation events in a few selected plain regions between 1951 and 2019. Besides the Great Hungarian Plain we chose two plain regions located in the southern part of the continent (i.e. the Po Valley and the Romanian Plain) with the purpose of comparing similar geographical regions, and creating a scientific basis to comprehensively analyse the effects of climate change on economy, society, and nature. For choosing the plains, objective criteria were used, namely, (i) the elevation remains under 200 m throughout the defined area, and (ii) the difference between the neighbouring grid points within the plain region does not exceed 50 m. The analysis of extreme precipitation events was performed for annual periods by calculating 17 climate indices. Based on our research of the past, there is a clear increase in the frequency and intensity of extreme precipitation events, in the length of dry periods as well as in the occurrence of extreme weather events.

2018 ◽  
Vol 17 (1) ◽  
pp. 38-46
Author(s):  
Sanjeevan Shrestha ◽  
Tina Baidar

Climate change, particularly at South Asia region is having a huge impact on precipitation patterns, its intensity and extremeness. Mountainous area is much sensitive to these extreme events, hence having adverse effect on environment as well as people in term of fluctuation in water supply as well as frequent extreme weather events such as flood, landslide etc. So, prediction of extreme precipitation is imperative for proper management. The objective of this study was to assess the spatial distribution and temporal change of extreme precipitation events on Koshi basin of Nepal during 1980-2010. Five indicators (R1day, R5 day, R > 25.4 mm, SDII and CDD) were chosen for 41 meteorological stations to test the extreme events. Inverse distance weighting and kriging interpolation technique was used to interpolate the spatial patterns. Result showed that most extreme precipitation events increased up to mountain regions from low river valley; and then it decreased subsequently up to Himalayan regions (south to north direction). However, there is high value of indices for lowland Terai valley also. Most of the indices have hotspot with higher value at north western and southern part of the study area. For temporal change, most of the extreme precipitation indices showed increasing trend within 30 years’ period. The spatial distribution of temporal change in indices suggests that there is increasing trend in lowland area and decreasing trend in mountainous and Himalayan area. So, adaptive measure should be adopted through proper land use planning, especially at those hotspot areas and their tributaries; to reduce adverse effect of extreme precipitation events.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Michele E. Morgado ◽  
Chengsheng Jiang ◽  
Jordan Zambrana ◽  
Crystal Romeo Upperman ◽  
Clifford Mitchell ◽  
...  

Abstract Background Infections with nontyphoidal Salmonella cause an estimated 19,336 hospitalizations each year in the United States. Sources of infection can vary by state and include animal and plant-based foods, as well as environmental reservoirs. Several studies have recognized the importance of increased ambient temperature and precipitation in the spread and persistence of Salmonella in soil and food. However, the impact of extreme weather events on Salmonella infection rates among the most prevalent serovars, has not been fully evaluated across distinct U.S. regions. Methods To address this knowledge gap, we obtained Salmonella case data for S. Enteriditis, S. Typhimurium, S. Newport, and S. Javiana (2004-2014; n = 32,951) from the Foodborne Diseases Active Surveillance Network (FoodNet), and weather data from the National Climatic Data Center (1960-2014). Extreme heat and precipitation events for the study period (2004-2014) were identified using location and calendar day specific 95th percentile thresholds derived using a 30-year baseline (1960-1989). Negative binomial generalized estimating equations were used to evaluate the association between exposure to extreme events and salmonellosis rates. Results We observed that extreme heat exposure was associated with increased rates of infection with S. Newport in Maryland (Incidence Rate Ratio (IRR): 1.07, 95% Confidence Interval (CI): 1.01, 1.14), and Tennessee (IRR: 1.06, 95% CI: 1.04, 1.09), both FoodNet sites with high densities of animal feeding operations (e.g., broiler chickens and cattle). Extreme precipitation events were also associated with increased rates of S. Javiana infections, by 22% in Connecticut (IRR: 1.22, 95% CI: 1.10, 1.35) and by 5% in Georgia (IRR: 1.05, 95% CI: 1.01, 1.08), respectively. In addition, there was an 11% (IRR: 1.11, 95% CI: 1.04-1.18) increased rate of S. Newport infections in Maryland associated with extreme precipitation events. Conclusions Overall, our study suggests a stronger association between extreme precipitation events, compared to extreme heat, and salmonellosis across multiple U.S. regions. In addition, the rates of infection with Salmonella serovars that persist in environmental or plant-based reservoirs, such as S. Javiana and S. Newport, appear to be of particular significance regarding increased heat and rainfall events.


2015 ◽  
Vol 3 (6) ◽  
pp. 3983-4005 ◽  
Author(s):  
S. O. Krichak ◽  
S. B. Feldstein ◽  
P. Alpert ◽  
S. Gualdi ◽  
E. Scoccimarro ◽  
...  

Abstract. Extreme precipitation events in the Mediterranean region during the cool season are strongly affected by the export of moist air from tropical and subtropical areas into the extratropics. The aim of this paper is to present a discussion of the major research efforts on this subject and to formulate a summary of our understanding of this phenomenon, along with its recent past trends from a climate change perspective. The issues addressed are: a discussion of several case studies; the origin of the air moisture and the important role of atmospheric rivers for fueling the events; the mechanism responsible for the intensity of precipitation during the events, and the possible role of global warming in recent past trends in extreme weather events over the Mediterranean region.


2020 ◽  
Vol 12 (4) ◽  
pp. 1415
Author(s):  
Runze Tong ◽  
Wenchao Sun ◽  
Quan Han ◽  
Jingshan Yu ◽  
Zaifeng Tian

Extreme weather events can cause a lot of damage in highly populated regions, such as in the Beijing–Tianjin–Hebei Region (BTHR) in northern China. To understand where and how extreme precipitation and temperature events are changing within the BTHR, data for 1959–2018 from 25 mereological stations were used to detect trends in the intensity, frequency, and duration of these events. The results showed that intensity, accumulated amount, the duration of extreme precipitation events, and the annual number of days with precipitation greater than 50 mm decreased on a regional scale over this 60-year period. Changes in extreme precipitation events at most stations were not statistically significant, although a few stations had a significant downward trend. The combined effects of the East Asian summer monsoon and rapid urbanization are possible reasons for these trends. Both the annual maximum and minimum temperature increased on a regional and local scale. The frequency of extreme hot and cold weather also, respectively, increased and decreased, with consistent patterns on a regional and local scale. However, the spatial changes of these trends were different, reflecting the effects of irrigation and urbanization on the regional surface energy balance. These findings are valuable to decisionmakers involved in disaster prevention in the BTHR and in other highly populated regions worldwide.


2021 ◽  
Author(s):  
Alexandra Berényi ◽  
Rita Pongrácz ◽  
Judit Bartholy

<p>The effects of climate change on precipitation patterns can be observed on global scale, however, global climate change affects different regions more or less severely. Because of the high variability of precipitation in particular, future changes related to precipitation can be very different, even opposite on continental/regional scale. Even within Europe, the detected trends in precipitation patterns and extremes differ across the continent. According to climate model simulations for the future, Northern Europe is projected to become wetter, while the southern parts of the continent will tend to become drier by the end of the 21st century. The frequency and intensity of extreme precipitation will also increase in the whole continent. The possible shifts in precipitation patterns from wetter to drier conditions with fewer but increased extreme precipitation events can cause severe natural hazards, such as extended drought periods, water scarcity, floods and flash floods, therefore appropriate risk management is essential. For this purpose the analysis of possible hazards associated to specific precipitation-related weather phenomena is necessary and serves as key input.</p><p>Since plain regions play an important role in agricultural economy and are more exposed to floods because of their geographic features and the gravitational movement of surface water, our primary goal was to examine temporal and spatial changes in extreme precipitation events and dry spells in three European lowlands, located in the southern part of the continent. We selected the following regions: the Po-Valley located in Italy with humid subtropical climate; the Romanian Plain in Romania, and the Pannonian Plain covering different parts of Hungary, Serbia, Slovakia, Croatia, Romania and Ukraine with humid continental climatic conditions.</p><p>Precipitation time series were used from the E-OBS v.22 dataset on a 0.1° regular grid. The dataset is based on station measurements from Europe and are available from 1950 onward with daily temporal resolution. For the analysis of main precipitation patterns, dry spells and extreme events, we use 17 climate indices (most of them are defined by the Expert Team on Climate Change Detection and Indices, ECCDI). The analysis focuses on annual and seasonal changes in the three regions. The selected indices are capable to represent the differences and similarities between and within the plains. Our preliminary results show that the occurrence and intensity of extreme precipitation events increased in all regions, while the trends of duration and frequency of dry spells show both intra- and inter regional variability across the plains.</p>


Author(s):  
Donghui Lu ◽  
Susan L. Tighe ◽  
Wei-Chau Xie

Pavement infrastructure is experiencing unanticipated climate conditions caused by global warming. Extreme weather events, such as extreme precipitations, are increasing in intensity and frequency, creating rising concern in pavement vulnerability and resilience analysis. Previous design approaches based on historical climate data may no longer be adequate for addressing future conditions. To promote pavement resilience under climate change, assessing pavement risk for extreme events is essential for prioritizing vulnerable infrastructure and developing adaptation strategies. The objective of this study is to develop a quantitative evaluation methodology for assessing pavement risk from extreme precipitations under climate change. Hazard analysis, fragility modeling, and cost estimation are the three major components for risk evaluation. An ensemble of 24 global climate models is used for predicting future extreme precipitations under various climate-forcing scenarios. The Mechanistic-Empirical Pavement Design Guide is employed to simulate performance change for performing fragility modeling. Risk assessment models considering a full range of hazards were used to quantify risk of asset value loss over specified analysis periods. Results indicate that future extreme precipitation events are expected to cause an increased medium risk of asset value loss. However, high uncertainties are involved in the estimation owing to variations in predicted climates. Major pavement damages do not necessarily equate with highest risk because the probability of occurrence of major damage is relatively lower. The proposed approach provides a practical tool for analyzing the interaction among extreme precipitation levels, pavement designs, damage states, occurrence probability, and asset value at risk.


2019 ◽  
Vol 20 (2) ◽  
pp. 275-296 ◽  
Author(s):  
Yang Yang ◽  
Thian Yew Gan ◽  
Xuezhi Tan

Abstract In the past few decades, there have been more extreme climate events occurring worldwide, including Canada, which has also suffered from many extreme precipitation events. In this paper, trend analysis, probability distribution functions, principal component analysis, and wavelet analysis were used to investigate the spatial and temporal patterns of extreme precipitation events of Canada. Ten extreme precipitation indices were calculated using long-term daily precipitation data (1950–2012) from 164 Canadian gauging stations. Several large-scale climate patterns such as El Niño–Southern Oscillation (ENSO), Pacific decadal oscillation (PDO), Pacific–North American (PNA), and North Atlantic Oscillation (NAO) were selected to analyze the relationships between extreme precipitation and climate indices. Convective available potential energy (CAPE), specific humidity, and surface temperature were employed to investigate potential causes of trends in extreme precipitation. The results reveal statistically significant positive trends for most extreme precipitation indices, which means that extreme precipitation of Canada has generally become more severe since the mid-twentieth century. The majority of indices display more increasing trends along the southern border of Canada while decreasing trends dominated the central Canadian Prairies. In addition, strong teleconnections are found between extreme precipitation and climate indices, but the effects of climate patterns differ from region to region. Furthermore, complex interactions of climate patterns with synoptic atmospheric circulations can also affect precipitation variability, and changes to the summer and winter extreme precipitation could be explained more by the thermodynamic impact and the combined thermodynamic and dynamic effects, respectively. The seasonal CAPE, specific humidity, and temperature are correlated to Canadian extreme precipitation, but the correlations are season dependent, which could be positive or negative.


Ecology ◽  
2021 ◽  
Author(s):  
Alison K. Post ◽  
Kristin P. Davis ◽  
Jillian LaRoe ◽  
David L. Hoover ◽  
Alan K. Knapp

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