scholarly journals Supplementary material to "More frequent flash flood events and extreme precipitation favouring atmospheric conditions in temperate regions of Europe"

2021 ◽  
Author(s):  
Judith Meyer ◽  
Malte Neuper ◽  
Luca Mathias ◽  
Erwin Zehe ◽  
Laurent Pfister
Keyword(s):  
Extreme Precipitation ◽  
Flash Flood ◽  
Atmospheric Conditions ◽  
Flood Events ◽  
Supplementary Material

scholarly journals More frequent flash flood events and extreme precipitation favouring atmospheric conditions in temperate regions of Europe

2021 ◽  
Author(s):  
Judith Meyer ◽  
Malte Neuper ◽  
Luca Mathias ◽  
Erwin Zehe ◽  
Laurent Pfister
Keyword(s):  
Extreme Precipitation ◽  
Western Europe ◽  
Flash Flood ◽  
Flash Floods ◽  
Water Levels ◽  
Specific Humidity ◽  
Atmospheric Conditions ◽  
Flood Events ◽  
Extreme Precipitation Events ◽  
Precipitation Events

Abstract. In recent years, flash floods repeatedly occurred in temperate regions of central western Europe. Unlike in Mediterranean catchments, this flooding behaviour is unusual. In the past, and especially in the 1990s, floods were characterized by predictable, slowly rising water levels during winter and driven by westerly atmospheric fluxes (Pfister et al., 2004). The intention of this study is to link the recent occurrence of flash floods in central western Europe to extreme precipitation and specific atmospheric conditions to identify the cause for this apparent shift. Therefore, we hypothesise that an increase in extreme precipitation events has subsequently led to an increase in the occurrence of flash flood events in central western Europe and all that being caused by a change in the occurrence of flash flood favouring atmospheric conditions. To test this hypothesis, we compiled data on flash floods in central western Europe and selected precipitation events above 40 mm h−1 from radar data (RADOLAN, DWD). Moreover, we identified proxy parameters representative for flash flood favouring atmospheric conditions from the ERA5 reanalysis dataset. High specific humidity in the lower troposphere (q ≥ 0.004 kg kg−1), sufficient latent instability (CAPE ≥ 100 J kg−1) and weak deep-layer wind shear (DLS ≤ 10 m s−1) proved to be characteristic for long-lasting intense rainfall that can potentially trigger flash floods. These atmospheric parameters, as well as the flash flood and precipitation events were then analysed using linear models. Thereby we found significant increases in atmospheric moisture contents and increases in atmospheric instability. Parameters representing the motion and organisation of convective systems occurred slightly more often or remained unchanged in the time period from 1981–2020. Moreover, a trend in the occurrence of flash floods was confirmed. The number of precipitation events, their maximum 5-minute intensities as well as their hourly sums were however characterized by large inter-annual variations and no trends could be identified between 2002–2020. This study therefore shows that the link from atmospheric conditions via precipitation to flash floods cannot be traced down in an isolated way. The complexity of interactions is likely higher and future analyses should include other potentially relevant factors such as intra-annual precipitation patterns or catchment specific parameters.

Identifying and linking flash flood prone atmospheric conditions to flooding occurrences in central Western Europe

2021 ◽  
Author(s):  
Judith Meyer ◽  
Audrey Douinot ◽  
Malte Neuper ◽  
Luca Mathias ◽  
Carol Tamez-Meléndez ◽  
...  
Keyword(s):  
River Basin ◽  
Western Europe ◽  
Flash Flood ◽  
Flash Floods ◽  
Precipitation Data ◽  
Atmospheric Conditions ◽  
Flood Events ◽  
Atmospheric Parameters ◽  
Circulation Patterns ◽  
Daily Precipitation Data

<p>In recent years, flash floods occurred repeatedly in temperate regions of central Western Europe (e.g., Orlacher Bach (GER), Hupselsebeek (NL), White Ernz (LUX)). This type of extreme flood events is unusual for these regions, as opposed to Mediterranean catchments that are more prone to flash floods. In the second half of the 20<sup>th</sup> century, and more specifically in the 1990’s, westerly atmospheric fluxes were the dominating triggering factor of large scale (winter) floods in central Western Europe.</p><p>With a view to gain a better understanding of the mechanisms controlling the recent flash flood events at higher latitudes, we explore various avenues related to the non-stationarity of environmental systems. We hypothesize that an increase in the occurrence of flash flood prone atmospheric conditions has recently led to higher precipitation totals and a subsequent increase in flash flood events in central Western Europe.</p><p>Therefore, we first analysed relevant atmospheric parameters from the ERA 5 reanalysis dataset. Second, we linked the atmospheric parameters to the concept of general circulation patterns as per Hess and Brezowsky (1977). Third, we analysed precipitation data from a set of stations located in the Moselle river basin (35.000 km<sup>2</sup>). These three pillars build the base for identifying flash flood prone atmospheric conditions over space and time that are then compared to actual occurrences of extreme discharge events in streams within the Moselle river basin.</p><p>To validate our hypothesis, spatial and temporal patterns in the occurrence of extreme precipitation and discharge events need to match atmospheric patterns. Preliminary results suggest that daily precipitation data and meridional circulation patterns do not show a clear trend towards an increased occurrence of precipitation events or higher precipitation amounts. Due to the limitations inherent to the available long-term dataset of daily data, the hypothesis can only be partly evaluated, and more detailed analyses are added. For that reason, discharge data with a 15-minute resolution, along with precipitation radar data of 5-minute time steps will be employed at a limited spatial extent in future analyses. In case of rejection of our working hypothesis this may pinpoint to other flash flood triggering mechanisms, such as changes in land use, soil moisture conditions or cultivation methods.</p>

Effects of 2017 Early Flash Flooding on Agriculture in Haor Areas of Sunamganj

2021 ◽  
Vol 12 (1-2) ◽  
pp. 117-125
Author(s):  
S Mondal ◽  
L Akter ◽  
HJ Hiya ◽  
MA Farukh
Keyword(s):  
Agricultural Production ◽  
Flash Flood ◽  
Eastern Region ◽  
Fish Production ◽  
Flood Events ◽  
Flash Flooding ◽  
The North ◽  
North Eastern ◽  
Boro Rice

The Sunamganj district is covered by major Haor systems in the north-eastern region of Bangladesh. Flash flood is the most commonly occurring water related disaster in the Haor areas. During the flash flood it is very common that people lost their primary agricultural productions which are the only source of their livelihood. The present study focuses on the effects of 2017 early flash flooding on rice and fish production of Sunamganj Haor areas. The flood caused enormous damage to agriculture such as rice especially Boro rice and fish production on which the Haor dwellers rely upon for their livelihood. The total affected land of Boro rice cultivation in Haors of Sunamganj was 149,224 hectare and the total amount of damaged rice was 393,855 metric ton (MT). The total number of affected farmers was 315,084. The early flash flood also affects the quality of Haor water which caused the death of fishes. The total amount of damaged fish was 49.75 MT and the loss was 158.70 lakh taka. The total number of affected fishermen was 44,445. This findings could be very useful for the environmental scientists to predict the probable future effects on agricultural production due to early flash flood events in Sunamganj Haors areas. Environ. Sci. & Natural Resources, 12(1&2): 117-125, 2019

Representative flash flood events in Romania Case studies

2008 ◽  
pp. 1587-1596
Author(s):  
G Stancalie ◽  
B Antonescu ◽  
C Oprea ◽  
A Irimescu ◽  
S Catana ◽  
...  
Keyword(s):  
Case Studies ◽  
Flash Flood ◽  
Flood Events

Methodology for risk assessment of flash flood events due to climate and land use changes

2012 ◽  
Author(s):  
M Velasco ◽  
A Cabello ◽  
I Escaler ◽  
J Barredo ◽  
A Barrera-Escoda
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Flash Flood ◽  
Land Use Changes ◽  
Flood Events

scholarly journals MobRISK: a model for assessing the exposure of road users to flash flood events

2017 ◽  
Vol 17 (9) ◽  
pp. 1631-1651 ◽  
Author(s):  
Saif Shabou ◽  
Isabelle Ruin ◽  
Céline Lutoff ◽  
Samuel Debionne ◽  
Sandrine Anquetin ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Flash Flood ◽  
Activity Patterns ◽  
Traffic Load ◽  
Road User ◽  
Population Exposure ◽  
Flood Events ◽  
Population Mobility ◽  
Road Users ◽  
Adverse Weather

Abstract. Recent flash flood impact studies highlight that road networks are often disrupted due to adverse weather and flash flood events. Road users are thus particularly exposed to road flooding during their daily mobility. Previous exposure studies, however, do not take into consideration population mobility. Recent advances in transportation research provide an appropriate framework for simulating individual travel-activity patterns using an activity-based approach. These activity-based mobility models enable the prediction of the sequence of activities performed by individuals and locating them with a high spatial–temporal resolution. This paper describes the development of the MobRISK microsimulation system: a model for assessing the exposure of road users to extreme hydrometeorological events. MobRISK aims at providing an accurate spatiotemporal exposure assessment by integrating travel-activity behaviors and mobility adaptation with respect to weather disruptions. The model is applied in a flash-flood-prone area in southern France to assess motorists' exposure to the September 2002 flash flood event. The results show that risk of flooding mainly occurs in principal road links with considerable traffic load. However, a lag time between the timing of the road submersion and persons crossing these roads contributes to reducing the potential vehicle-related fatal accidents. It is also found that sociodemographic variables have a significant effect on individual exposure. Thus, the proposed model demonstrates the benefits of considering spatiotemporal dynamics of population exposure to flash floods and presents an important improvement in exposure assessment methods. Such improved characterization of road user exposures can present valuable information for flood risk management services.

scholarly journals PEMANFAATAN DATA SATELIT HIMAWARI-8 SERTA DATA CURAH HUJAN DAN HARI HUJAN BULANAN DALAM ANALISIS KEJADIAN BANJIR KOTA PADANG, 9 SEPTEMBER 2017 DAN 26 SEPTEMBER 2018

2019 ◽  
Vol 3 ◽  
pp. 264
Author(s):  
Vinca Amalia Rizkiafama ◽  
Tesla Kadar Dzikiro ◽  
Agus Safril
Keyword(s):  
Satellite Data ◽  
Atmospheric Stability ◽  
Convective Cloud ◽  
Atmospheric Conditions ◽  
Flood Events ◽  
Growth Activity ◽  
One Year ◽  
Almost All ◽  
The City ◽  
Rainy Days

<p class="AbstractEnglish"><strong>Abstract:</strong> Flood events on Wednesday, September 26, 2018, in several sub-districts in the city of Padang showed different conditions with the Indonesian region in general which were in normal to drier conditions. One year earlier, precisely on September 9, 2017, there were floods in almost all areas of the city of Padang. This study aims to determine the atmospheric conditions during flood events from the climatological and meteorological side. The data used are monthly rainfall and a monthly number of Rainy Days (HH) from 1981-2018 from the Minangkabau Meteorological Station, as well as Himawari-8 Weather Satellite data. Satellite data is processed using Satellite Animation and Interactive Diagnosis (SATAID) software to obtain cloud cover analysis, cloud growth activities, and atmospheric lability levels. September 2017 and September 2018 are in the nature of normal rain with a percentage of 101% and 88%. The increase in the amount of rainfall in August 2017 to September 2017 is not significant at 27 mm compared to August 2018 to September 2018 which is significant at 148 mm. The number of rainy days in September 2017 and 2018 were 24 and 23 respectively, which showed that almost every day there was rain in those months. The meteorological analysis shows that there is convective cloud growth activity in the Padang area which is characterized by an unstable level of atmospheric stability which has the potential for moderate to heavy rainfall.</p><p class="KeywordsEngish"><strong>Abstrak:</strong> Kejadian banjir pada Rabu, 26 September 2018 di beberapa kecamatan di Kota Padang menunjukkan kondisi yang berlainan dengan wilayah Indonesia pada umumnya yang berada dalam kondisi normal hingga lebih kering. Satu tahun sebelumnya, tepatnya pada 9 September 2017 juga terjadi banjir hampir di seluruh wilayah Kota Padang. Penelitian ini bertujuan untuk mengetahui kondisi atmosfer pada saat kejadian banjir dari sisi klimatologis dan meteorologisnya. Data yang digunakan adalah curah hujan bulanan dan jumlah Hari Hujan (HH) bulanan dari tahun 1981-2018 dari Stasiun Meteorologi Minangkabau, serta data Satelit Cuaca Himawari-8. Data satelit diolah menggunakan piranti lunak Satellite Animation and Interactive Diagnosis (SATAID) untuk mendapatkan analisis tutupan awan, aktivitas pertumbuhan awannya, dan tingkat labilitas atmosfer. September 2017 dan September 2018 berada pada sifat hujan normal dengan presentase 101% dan 88%. Peningkatan jumlah curah hujan bulan Agustus 2017 ke September 2017 tidak signifikan yaitu sebesar 27 mm dibandingkan Agustus 2018 ke September 2018 yang signifikan yaitu sebesar 148 mm. Jumlah hari hujan di bulan September 2017 dan 2018 berturut-turut sebesar 24 dan 23 yang menunjukkan bahwa hampir setiap hari terjadi hujan di bulan-bulan tersebut. Analisis secara meteorologis menunjukkan bahwa terdapat aktivitas pertumbuhan awan konvektif di daerah Padang yang ditandai dengan tingkat stabilitas atmosfer yang labil sehingga berpotensi terjadinya hujan sedang hingga lebat.</p>

scholarly journals Review Article: Atmospheric conditions inducing extreme precipitation over the Eastern and Western Mediterranean

2015 ◽  
Vol 3 (6) ◽  
pp. 3687-3732 ◽  
Author(s):  
U. Dayan ◽  
K. M. Nissen ◽  
U. Ulbrich
Keyword(s):  
Extreme Precipitation ◽  
Mediterranean Basin ◽  
Heavy Rainfall ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Atmospheric Conditions ◽  
Synoptic Scale ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes producing heavy rain storms. It distinguishes the Western and Eastern Mediterranean in order to point at specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger scale circulations. The synoptic systems (tropical and extra-tropical) accounting for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper-level synoptic-scale troughs, and meso-scale convective systems. Under tropical air mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

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