scholarly journals The Impact of Tropical Cyclone Seroja to The Rainfall and Sea Wave Height in East Nusa Tenggara

2021 ◽  
Vol 925 (1) ◽  
pp. 012049
Author(s):  
R Kurniawan ◽  
H Harsa ◽  
M H Nurrahmat ◽  
A Sasmito ◽  
N Florida ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Wave Height ◽  
Extreme Rainfall ◽  
Active Phase ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
The Indian Ocean ◽  
The Impact ◽  
The City ◽  
Sea Wave

Abstract Natural events following the activity of the Tropical Cyclone Seroja in April 2021 are investigated. During its active phase, Tropical Cyclone Seroja generated extreme rainfall events in some sub-provinces of East Nusa Tenggara (NTT): Ngada, Alor, Belu, Rote Ndao on 4 April, 2021, Kupang on 4 to 5 April, 2021, East Sumba on 4 to 6 April, 2021. Moreover, these extreme rainfall events triggered flood in Alor, East Flores, Lembata, The City of Kupang, Kupang, East Sumba, Malaka, Belu, and North Central Timor. The maximum sea wave height of the Indian Ocean at the Southern part of NTT was also increasing, from 4 meters on 1 to 2 April, 2021 up to 6 meters on 3 April, 2021, and rose to higher than 7 meters on 4 to 6 April, 2021. On 7 to 9 April, 2021, the sea wave height declined as the Tropical Cyclone Seroja moved to the Southwest of NTT.

scholarly journals Tropical cyclone contribution to extreme rainfall over southwest Pacific Island nations

2021 ◽  
Author(s):  
Anil Deo ◽  
Savin S. Chand ◽  
Hamish Ramsay ◽  
Neil J. Holbrook ◽  
Simon McGree ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
El Niño ◽  
El Nino ◽  
Extreme Rainfall ◽  
Pacific Island ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Southwest Pacific ◽  
Inactive Phase ◽  
Pacific Island Nations

AbstractSouthwest Pacific nations are among some of the worst impacted and most vulnerable globally in terms of tropical cyclone (TC)-induced flooding and accompanying risks. This study objectively quantifies the fractional contribution of TCs to extreme rainfall (hereafter, TC contributions) in the context of climate variability and change. We show that TC contributions to extreme rainfall are substantially enhanced during active phases of the Madden–Julian Oscillation and by El Niño conditions (particularly over the eastern southwest Pacific region); this enhancement is primarily attributed to increased TC activity during these event periods. There are also indications of increasing intensities of TC-induced extreme rainfall events over the past few decades. A key part of this work involves development of sophisticated Bayesian regression models for individual island nations in order to better understand the synergistic relationships between TC-induced extreme rainfall and combinations of various climatic drivers that modulate the relationship. Such models are found to be very useful for not only assessing probabilities of TC- and non-TC induced extreme rainfall events but also evaluating probabilities of extreme rainfall for cases with different underlying climatic conditions. For example, TC-induced extreme rainfall probability over Samoa can vary from ~ 95 to ~ 75% during a La Niña period, if it coincides with an active or inactive phase of the MJO, and can be reduced to ~ 30% during a combination of El Niño period and inactive phase of the MJO. Several other such cases have been assessed for different island nations, providing information that have potentially important implications for planning and preparing for TC risks in vulnerable Pacific Island nations.

Extreme rainfall events during and following heatwaves

2021 ◽  
Author(s):  
Christoph Sauter ◽  
Christopher White ◽  
Hayley Fowler ◽  
Seth Westra
Keyword(s):  
Natural Hazards ◽  
Rainfall Intensity ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Rainfall Extremes ◽  
Average Rainfall ◽  
Time Of Year ◽  
The Impact

<p>Heatwaves and extreme rainfall events are natural hazards that can have severe impacts on society. The relationship between temperature and extreme rainfall has received scientific attention with studies focussing on how single daily or sub-daily rainfall extremes are related to day-to-day temperature variability. However, the impact multi-day heatwaves have on sub-daily extreme rainfall events and how extreme rainfall properties change during different stages of a heatwave remains mostly unexplored.</p><p>In this study, we analyse sub-daily rainfall records across Australia, a country that experiences severe natural hazards on a frequent basis, and determine their extreme rainfall properties, such as rainfall intensity, duration and frequency during SH-summer heatwaves. These properties are then compared to extreme rainfall properties found outside heatwaves, but during the same time of year, to examine to what extent they differ from normal conditions. We also conduct a spatial analysis to investigate any spatial patterns that arise.</p><p>We find that rainfall breaking heatwaves is often more extreme than average rainfall during the same time of year. This is especially prominent on the eastern and south-eastern Australian coast, where frequency and intensity of sub-daily rainfall extremes show an increase during the last day or the day immediately after a heatwave. We also find that although during heatwaves the average rainfall amount and duration decreases, there is an increase in sub-daily rainfall intensity when compared to conditions outside heatwaves. This implies that even though Australian heatwaves are generally characterised by dry conditions, rainfall occurrences within heatwaves are more intense.</p><p>Both heatwaves and extreme rainfall events pose great challenges for many sectors such as agriculture, and especially if they occur together. Understanding how and to what degree these events co-occur could help mitigate the impacts caused by them.</p>

scholarly journals Riverbed Migrations in Western Taiwan under Climate Change

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1631 ◽  
Author(s):  
Yi-Chiung Chao ◽  
Chi-Wen Chen ◽  
Hsin-Chi Li ◽  
Yung-Ming Chen
Keyword(s):  
Climate Change ◽  
21St Century ◽  
Peak Flow ◽  
Extreme Rainfall ◽  
Base Period ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Flow Discharge ◽  
The Future ◽  
The Impact

In recent years, extreme weather phenomena have occurred worldwide, resulting in many catastrophic disasters. Under the impact of climate change, the frequency of extreme rainfall events in Taiwan will increase, according to a report on climate change in Taiwan. This study analyzed riverbed migrations, such as degradation and aggradation, caused by extreme rainfall events under climate change for the Choshui River, Taiwan. We used the CCHE1D model to simulate changes in flow discharge and riverbed caused by typhoon events for the base period (1979–2003) and the end of the 21st century (2075–2099) according to the climate change scenario of representative concentration pathways 8.5 (RCP8.5) and dynamical downscaling of rainfall data in Taiwan. According to the results on flow discharge, at the end of the 21st century, the average peak flow during extreme rainfall events will increase by 20% relative to the base period, but the time required to reach the peak will be 8 h shorter than that in the base period. In terms of the results of degradation and aggradation of the riverbed, at the end of the 21st century, the amount of aggradation will increase by 33% over that of the base period. In the future, upstream sediment will be blocked by the Chichi weir, increasing the severity of scouring downstream. In addition, due to the increased peak flow discharge in the future, the scouring of the pier may be more serious than it is currently. More detailed 2D or 3D hydrological models are necessary in future works, which could adequately address the erosive phenomena created by bridge piers. Our results indicate that not only will flood disasters occur within a shorter time duration, but the catchment will also face more severe degradation and aggradation in the future.

scholarly journals The impact of atmospheric rivers on rainfall in New Zealand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingxiang Shu ◽  
Asaad Y. Shamseldin ◽  
Evan Weller
Keyword(s):  
New Zealand ◽  
Austral Summer ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Detection Algorithm ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Atmospheric Rivers ◽  
Hydrological Hazards ◽  
The Impact

AbstractThis study quantifies the impact of atmospheric rivers (ARs) on rainfall in New Zealand. Using an automated AR detection algorithm, daily rainfall records from 654 rain gauges, and various atmospheric reanalysis datasets, we investigate the climatology of ARs, the characteristics of landfalling ARs, the contribution of ARs to annual and seasonal rainfall totals, and extreme rainfall events between 1979 and 2018 across the country. Results indicate that these filamentary synoptic features play an essential role in regional water resources and are responsible for many extreme rainfall events on the western side of mountainous areas and northern New Zealand. In these regions, depending on the season, 40–86% of the rainfall totals and 50–98% of extreme rainfall events are shown to be associated with ARs, with the largest contributions predominantly occurring during the austral summer. Furthermore, the median daily rainfall associated with ARs is 2–3 times than that associated with other storms. The results of this study extend the knowledge on the critical roles of ARs on hydrology and highlight the need for further investigation on the landfalling AR physical processes in relation to global circulation features and AR sources, and hydrological hazards caused by ARs in New Zealand.

scholarly journals Spatio-temporal Variability and Trends of Mean and Extreme Rainfall Events in the Sudano-sahelian Region of Cameroon

2021 ◽  
Author(s):  
Ibrahim NJOUENWET ◽  
Lucie A. Djiotang Tchotchou ◽  
Brian Odhiambo Ayugi ◽  
Guy Merlin Guenang ◽  
Derbetini A. Vondou ◽  
...  
Keyword(s):  
Climate Change ◽  
Extreme Rainfall ◽  
Temporal Variations ◽  
Annual Rainfall ◽  
Drought Risk ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Precipitation Concentration ◽  
Spatio Temporal ◽  
The Impact

Abstract The Sudano-Sahelian region of Cameroon is mainly drained by the Benue, Chari and Logone rivers, which are very useful for water resources, especially for irrigation, hydropower generation, and navigation. Long-term changes in mean and extreme rainfall events in the region may be of crucial importance in understanding the impact of climate change. Daily and monthly rainfall data from twenty-five synoptic stations in the study area from 1980 to 2019 and extreme indices from the Expert Team on Climate Change Detection and Indices (ETCCDI) measurements were estimated using the non-parametric Modified Mann-Kendall test and the Sen slope estimator. The precipitation concentration index (PCI), the precipitation concentration degree (PCD), and the precipitation concentration period (PCP) were used to explore the spatio-temporal variations in the characteristics of rainfall concentrations. An increase in extreme rainfall events was observed, leading to an upward trend in mean annual. Trends in consecutive dry days (CDD) are significantly increasing in most parts of the study area. This could mean that the prevalence of drought risk is higher in the study area. Overall, the increase in annual rainfall could benefit the hydro-power sector, agricultural irrigation, the availability of potable water sources, and food security.

Startegic framework for integrated flood Disaster modelling over Bangalore city of India

2021 ◽  
Author(s):  
Smrati Purwar ◽  
Gyanendranath Mohapatra ◽  
Rakesh Vasudevan
Keyword(s):  
Urban Landscape ◽  
Flash Flood ◽  
Warning System ◽  
Extreme Rainfall ◽  
High Elevation ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Bangalore City ◽  
Societal Relevance ◽  
The Impact

<p>Hydro-meteorological disasters, particularly the extreme rainfall events (EREs) and associated flash floods, are very frequent in the major metro cities in India during recent years and in many occasions they cause massive destruction to life and property which in long run make adverse socio-economic impacts over the country. Hence, it makes formost importance and has great societal relevance to modellers working such area to develop an advance prediction system for such disasters in India.A strategic framework combining modelling and data analytics is integral part of developing advanced warning system for preparedness during such disasters. In this study, the role of landuse/landcover like built-up, vegetation, barrenland and waterbodies over the Bangalore city in flash flood occurrence is examined using multispectral spatio-temporal satellite data.The recent LULC map evidences a drastic changes in urban landscape that resulted in loss of natural drainage and waterbeds causing frequent floods. Digital Elevation Map (DEM) is analysed to know the  low-lying and high elevation topography compared with  Mean Sea Level(MSL)to quantify the impact of flooding during Extreme Rainfall Events(ERE) on the different part of the Bangalore city. Using Triangular Irregular Network (TIN), flood simulation is carried out for highland and lowlandarea  to study immediate affected areas during EREs Storm Water Modelling  is carried out for different regions in the city to obtain flood pattern, time and volume during selected EREs. The framework developed and simulation results are very useful in generation of management and mitigation strategy by various user agencies.</p>

scholarly journals Seasonal intensity-duration-frequency relationships for Pelotas, Rio Grande do Sul, Brazil

2022 ◽  
Vol 26 (2) ◽  
pp. 85-90
Author(s):  
Emanuele B. Manke ◽  
Claudia F. A. Teixeira-Gandra ◽  
Rita de C. F. Damé ◽  
André B. Nunes ◽  
Maria C. C. Chagas Neta ◽  
...  
Keyword(s):  
Rio Grande ◽  
Extreme Rainfall ◽  
Rio Grande Do Sul ◽  
Extreme Rainfall Events ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Intensity Duration Frequency ◽  
Relationship Of ◽  
The Relationship ◽  
The City

ABSTRACT Although several studies have evaluated the intensity-duration-frequency relationships of extreme rainfall events, these relationships under different seasonal conditions remain relatively unknown. Thus, this study aimed to determine whether the intensity-duration-frequency relationships obtained seasonally from the rainfall records in the winter and summer represent the maximum rainfall events for the city of Pelotas, Rio Grande do Sul state, Brazil. Pluviographic data from 1982 to 2015 were used to create two seasonal series: one for the summer from December 21 to March 20 and the other for the winter from June 21 to September 22. These seasonal relationships were compared with the annual pluviographic data. The intensity, duration, and frequency relationships obtained from the summer rain data adequately represented the maximum rainfall in Pelotas, Rio Grande do Sul state, Brazil. The maximum intensity values of rainfall obtained from the relationship of intensity, duration, and frequency for the winter did not adequately encapsulate the occurrence of rain with greater intensities.

Tracing seismic landslide-derived sediment dynamics in response to climate change

2021 ◽  
Author(s):  
Jun Xie ◽  
Thomas Coulthard
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Landscape Evolution ◽  
Mass Movement ◽  
Extreme Rainfall ◽  
Channel Network ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Seismic Landslide ◽  
The Impact

<p>Mass movement such as landslides and rock fall is a prominent source of sediment in active mountain belt. Earthquake triggered landslides can generate substantial loose sediment and have significant geomorphic effects on long term landscape evolution. More importantly, these landslide impacts to land surface vary a lot due to the divergence of landslide characteristics and surrounding environment settings. Downslope and downstream transport of sediment into the channel network is fairly sensitive to climatic perturbations especially for extreme rainfall events. A wide variety of studies attempt to quantify or determine the contribution of landslide generated material to gross sediment budget and the corresponding retention time scale of landslide generated deposit in the mountain basin, whereas no established techniques can explicitly fingerprint/track landslide derived sediment. In this study, we first generated the hourly future extreme rainfall under two emission scenario (RCP4.5, RCP8.5) using ‘NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP)’ dataset. A new tracing function is incorporated into CAESAR-lisflood to track the landslide derived sediment footprint and dynamics in response to climate change. The landscape evolution at the Hongxi catchment, which is suffered tremendous damage from Wenchuan earthquake (Ms 8.0), are then simulated using CAESAR-lisflood under two climate scenarios. The results show that more than 80 percent of material generated by seismic landslides are still retained at the hillslope even after a sufficient time (e.g. 100 year). This study is to compare the spatial-temporal evolution pattern of landslides-derived sediment under two climatic scenarios (RCP4.5, RCP8.5), thus probing into the landslide generated sediment transport and budget respond to the climate change especially the impact of extreme rainfall events. Numerical modelling can provide a quick and effective tool for broad scale predictions of sediment produced by landslide events under different climatic predictions, which is of great importance for seismic induced disaster protection and reduction under climate change.</p>

scholarly journals The Impact of Atmospheric Rivers on Rainfall in New Zealand

2021 ◽  
Author(s):  
Assad Shamseldin ◽  
Evan Weller ◽  
Jingxiang Shu
Keyword(s):  
New Zealand ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Atmospheric Rivers ◽  
Hydrological Hazards ◽  
Synoptic Features ◽  
Western Side ◽  
The Impact

Abstract This study quantifies the impact of atmospheric rivers (ARs) on rainfall in New Zealand. Using daily rainfall records from 654 rain gauges and the ERA-Interim and ERA-5 reanalysis, we investigate the contribution of ARs to the annual and seasonal rainfall totals and extreme rainfall events between 1979–2018 across the country. Results indicate that these filamentary synoptic features play an essential role in regional water resources and are responsible for many extreme rainfall events on the western side of mountainous areas and northern New Zealand. Depending on the season in these areas, 40–86% of the rainfall totals and 50–98% of extreme rainfall events are shown to be associated with ARs, with the largest contributions predominantly occurring during the summer. Furthermore, the median daily rainfall associated with ARs is 2–3 times that associated with other storms. The results of this study extend the knowledge of the critical roles of ARs on hydrology and highlight the need for further investigation of the hydrological hazards caused by ARs in New Zealand.

scholarly journals AQUEOUS ENVIRONMENT AND EFFECTS ON THE CIVIL AREAS: THE CASE OF NAFPLIO

2017 ◽  
Vol 43 (3) ◽  
pp. 1508 ◽  
Author(s):  
P. Sabatakakis ◽  
G. Koukis
Keyword(s):  
Time Series ◽  
Surface Water ◽  
Extreme Rainfall ◽  
Suburban Area ◽  
Aqueous Environment ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Exploratory Wells ◽  
The Impact ◽  
Surface And Groundwater

This paper made an effort through the data and conclusions drawn to highlight the impact of the water element, surface and groundwater in urban and suburban area of Nafplio. Through exploratory wells constructed for this reason ,water - measurements and water – chemical analysis carried out, made a series of thematic maps which are dimensioned Spatiotemporal rain water flocking to urban and suburban area in case of extreme rainfall events, illustrating the depth, the direction of groundwater flow and the corrosivity of groundwater in relation to the foundations. The accuracy of the figures obtained for surface water and groundwater is a function of time series and the density of the network, and certainly is indicative and could be much more detailed if the network was denser. In any case, this work tries to highlight the value that may have similar operations on urban planning and foundations.

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