scholarly journals Sub-Daily Rainfall Intensity Extremes: Evaluating Suitable Indices at Australian Arid and Wet Tropical Observing Sites

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2616 ◽  
Author(s):  
David Dunkerley
Keyword(s):  
Climate Change ◽  
Rainfall Intensity ◽  
Short Interval ◽  
Daily Rainfall ◽  
Secular Change ◽  
Intense Rainfall ◽  
Total Rainfall ◽  
Intensity Index ◽  
Diurnal Cycles ◽  
Simple Daily Intensity Index

Rainfall intensity extremes are relevant to many aspects of climatology, climate change, and landsurface processes. Intensity is described and analysed using a diversity of approaches, reflecting its importance in these diverse areas. The characteristics of short-interval intensity extremes, such as the maximum 5-min intensity, are explored here. It is shown that such indices may have marked diurnal cycles, as well as seasonal variability. Some indices of intensity, such as the SDII (simple daily intensity index), provide too little information for application to landsurface processes. Upper percentiles of the intensity distribution, such as the 95th and 99th percentiles (Q95 and Q99) are used as indices of extreme intensity, but problematically are affected by changes in intensity below the nominated threshold, as well as above it, making the detection of secular change, and application to sites with contrasting rainfall character, challenging. For application to landsurface processes, a new index is introduced. This index (RQ95), is that intensity or rainfall rate above which 5% of the total rainfall is delivered. This index better reflects intense rainfall than does Q95 of even 5-min accumulation duration (AD) rainfall depths. Such an index is helpful for detecting secular change at an observing station, but, like Q95, remains susceptible to the effects of change elsewhere in the distribution of intensities. For understanding impacts of climate and climate change on landsurface processes, it is argued that more inclusive indices of intensity are required, including fixed intensity criteria.

scholarly journals The Wet and Dry Spells across India during 1951–2007

2010 ◽  
Vol 11 (1) ◽  
pp. 26-45 ◽  
Author(s):  
Nityanand Singh ◽  
Ashwini Ranade
Keyword(s):  
Climate Change ◽  
Rainfall Intensity ◽  
Total Duration ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Change Scenario ◽  
Monsoon Period ◽  
Northwestern India ◽  
Area Of Interest ◽  
Dry Spells

Abstract Characteristics of wet spells (WSs) and intervening dry spells (DSs) are extremely useful for water-related sectors. The information takes on greater significance in the wake of global climate change and climate-change scenario projections. The features of 40 parameters of the rainfall time distribution as well as their extremes have been studied for two wet and dry spells for 19 subregions across India using gridded daily rainfall available on 1° latitude × 1° longitude spatial resolution for the period 1951–2007. In a low-frequency-mode, intra-annual rainfall variation, WS (DS) is identified as a “continuous period with daily rainfall equal to or greater than (less than) daily mean rainfall (DMR) of climatological monsoon period over the area of interest.” The DMR shows significant spatial variation from 2.6 mm day−1 over the extreme southeast peninsula (ESEP) to 20.2 mm day−1 over the southern-central west coast (SCWC). Climatologically, the number of WSs (DSs) decreases from 11 (10) over the extreme south peninsula to 4 (3) over northwestern India as a result of a decrease in tropical and oceanic influences. The total duration of WSs (DSs) decreases from 101 (173) to 45 (29) days, and the duration of individual WS (DS) from 12 (18) to 7 (11) days following similar spatial patterns. Broadly, the total rainfall of wet and dry spells, and rainfall amount and rainfall intensity of actual and extreme wet and dry spells, are high over orographic regions and low over the peninsula, Indo-Gangetic plains, and northwest dry province. The rainfall due to WSs (DSs) contributes ∼68% (∼17%) to the respective annual total. The start of the first wet spell is earlier (19 March) over ESEP and later (22 June) over northwestern India, and the end of the last wet spell occurs in reverse, that is, earlier (12 September) from northwestern India and later (16 December) from ESEP. In recent years/decades, actual and extreme WSs are slightly shorter and their rainfall intensity higher over a majority of the subregions, whereas actual and extreme DSs are slightly (not significantly) longer and their rainfall intensity weaker. There is a tendency for the first WS to start approximately six days earlier across the country and the last WS to end approximately two days earlier, giving rise to longer duration of rainfall activities by approximately four days. However, a spatially coherent, robust, long-term trend (1951–2007) is not seen in any of the 40 WS/DS parameters examined in the present study.

Increase in the frequency of heavy rainfall events over the UK in the light of climate change.

2020 ◽  
Author(s):  
Daniel Cotterill ◽  
Peter Stott ◽  
Elizabeth Kendon
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Heavy Rainfall ◽  
Daily Rainfall ◽  
Heavy Rainfall Event ◽  
Climate Projections ◽  
Intense Rainfall ◽  
Rainfall Events ◽  
Climate Forcings ◽  
The Uk

<p>We investigate the attribution of the flooding in Northern England that saw at least 500 homes flooded and over 1000 properties evacuated in flooded areas in 2019. This occurred during the wettest Autumn on record in some areas and also contained some very high daily rainfall totals. In the light of climate change, it is expected that intense rainfall events are to become more intense as a result of increased global average temperatures and the Clausius-Clapeyron relationship, but here we investigate quantitatively how much climate change has increased the risk of such an event to date.</p><p>We use results from the 2.2km convective permitting high resolution local UK Climate Projections (UKCP) and observations to show that more intense rainfall events may already be occurring in Autumn in the UK. This work shows using this high resolution UKCP data that a heavy rainfall event exceeding 50mm in one day in Autumn was 33-40% more likely to occur in 2019 than 1985. Further work that looks at the HadGEM3-A simulations shows that these heavy rainfall days are more likely to occur in a climate impacted by human activity than one with just natural climate forcings.</p>

scholarly journals Detecção de Mudanças Climáticas Através de Índices Pluviométricos Diários no Estado de Pernambuco (Detection of Climate Change Through Daily rainfall in the State of Pernambuco)

2013 ◽  
Vol 6 (4) ◽  
pp. 713 ◽  
Author(s):  
Priscila V. dos Santos ◽  
Rosaline Dos Santos ◽  
Maytê D. L. Coutinho
Keyword(s):  
Climate Change ◽  
Equatorial Pacific ◽  
The State ◽  
Total Precipitation ◽  
Tropical Atlantic ◽  
Intensity Index ◽  
Annual Total ◽  
Simple Daily Intensity Index ◽  
Consecutive Dry Days ◽  
Sst Anomalies

O objetivo do presente trabalho é estimar e analisar índices de detecção e monitoramento de mudanças climáticas, decorrentes da precipitação diária, para o Estado de Pernambuco, verificar sua possível dependência das anomalias de temperatura da superfície do mar e examinar suas influências sobre a dinâmica da vegetação, medida pelo Índice de Vegetação por Diferenças Normalizadas (IVDN), e variabilidade do clima, estimada pelo Índice Inverso de Aridez de Budyko (IIAB) anual. Para isso utilizou-se dados de precipitação totais diários de 26 localidades, anomalias de TSM para o período de 1964 a 2006, IVDN mensais de 1982 a 2001 e estimativa de temperaturas do ar média, máxima e mínima. Observou-se um decaimento da precipitação total anual, da intensidade simples diária da precipitação, dos dias consecutivos úmidos, dos dias com chuva superior a 20mm/dia e inferior a 50mm/dia, e aumento dos dias consecutivos secos. Verificou-se que, além do total anual de precipitação, o número de dias consecutivos secos, número de dias no ano com chuvas acima de 10mm/dia e intensidade simples diária de precipitação são dependentes dos padrões de anomalias de TSM nos Oceanos Pacífico Equatorial e Atlântico Tropical. O IVDN é influenciado pela precipitação total e pelo número de dias com chuvas superiores a 10mm/dia, principalmente no Alto Sertão do Estado. O índice inverso de aridez de Budyko é dependente das configurações das anomalias de TSM dos Oceanos Pacífico Equatorial e Atlântico Tropical Norte, e exerce influência sobre o IVDN. A B S T R A C T The objectives of the present work are: to compute and to analyze climate extreme indexes for monitoring and detecting climate change, for the state of Pernambuco; to verify the possible dependence of the extreme indexes of the anomalies of the sea surface temperature and to examine the influences of the extreme indexes on the dynamics of the vegetation, measured by NDVI (Normalized Difference Vegetation Index), and climate variability, evaluated for IIAB (Aridity Inverse Index of Budyko) annual. It was used precipitation diaries data from 26 meteorological stations, anomalies of SST for the period from 1964 to 2006, monthly NDVI from 1982 to 2001 and the mean, maxima and minima air temperature. It was observed a decline of the annual total precipitation, precipitation simple daily intensity index, consecutive wet days and days with superior rains to 20mm/day and inferior to 50mm/day. And it was verified an increase of the consecutive dry days. It was verified that the annual total of precipitation, number of consecutive dry days, number of days in the year with rains above 10mm/day and precipitation simple daily intensity index are dependent of the SST anomalies patterns on the Equatorial Pacific and Tropical Atlantic Oceans. NDVI is influenced by the total precipitation and for the number of days with superior rains to 10mm/day, mainly on the Sertão of the State. Aridity inverse index of Budyko is dependent of the SST anomalies configurations on the Equatorial Pacific and Northern Tropical Atlantic Oceans, and it exercises influence on NDVI. Keywords: climate, climatic changes, semiarid, coast.

scholarly journals Characterization of the variability in climate extremes in the Ferkessédougou sugar complexes (Northern Côte d'Ivoire)

2021 ◽  
Vol 384 ◽  
pp. 203-211
Author(s):  
Affoué Berthe Yao ◽  
Sampah Georges Eblin ◽  
Loukou Alexis Brou ◽  
Kouakou Lazare Kouassi ◽  
Gla Blaise Ouede ◽  
...  
Keyword(s):  
Climate Change ◽  
Methodological Approach ◽  
Extreme Temperature ◽  
Daily Rainfall ◽  
Climate Extremes ◽  
Climate Indices ◽  
Intense Rainfall ◽  
Adaptation To Climate Change ◽  
Average Decrease ◽  
Extreme Climate

Abstract. This study aims to analyse the frequency, intensity and duration of extreme climate events in order to optimise sugarcane production in the Ferkessédougou sugar complexes. The methodological approach is based on the calculation of extreme climate indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) from daily rainfall and temperature data observed at the Ferké 2 station over the period 1999–2018. The results show that the rainfall indices are negative, except for the number of consecutive dry days (CDD); this shows a decreasing trend in rainfall with, however, insignificant trends. Over the period 1999–2006, the number of intense rainfall days (R10 mm) decreased from 40 to 28 d with an average decrease of 0.3 d yr−1 and the number of very intense rainfall days (R20 mm) fluctuated between 26 and 2 d, with a slope of 0.083. The extreme temperature indices show statistically significant positive trends for the warm sequences; this confirms the rising of temperatures on both a local and national scale. This study could enable the Ferkessédougou sugar complexes managers to develop strategies for adaptation to climate change.

scholarly journals Recent trends in daily rainfall extremes over Montenegro (1951–2010)

2015 ◽  
Vol 3 (4) ◽  
pp. 2347-2377 ◽  
Author(s):  
D. Burić ◽  
J. Luković ◽  
B. Bajat ◽  
M. Kilibarda ◽  
V. Ducić
Keyword(s):  
North Atlantic ◽  
Rainfall Intensity ◽  
Daily Rainfall ◽  
Extreme Rainfall ◽  
Intense Rainfall ◽  
Rainfall Events ◽  
Rainfall Extremes ◽  
Expert Team ◽  
Recent Trends ◽  
Negative Impacts

Abstract. More intense rainfall may cause a range of negative impacts upon society and the environment. In this study we analyzed trends in extreme ETCCDI (Expert Team on Climate Change Detection and Indices) rainfall indices in Montenegro for the period 1951–2010. Montenegro has been poorly studied in terms of rainfall extremes, yet it contains the wettest Mediterranean region known as Krivošije. Several indices of precipitation extremes were assessed including the number of dry days and rainfall totals, and their trends to identify possible changes. The results generally suggest that the number of days with precipitation decreased while rainfall intensity increased particularly in south-western parts of the country. A slight tendency towards intense rainfall events is suggested. Calculated trends for each index are spatially presented and examined using a plotGoogleMaps software package. This study also examined spatial pattern of relationship between extreme rainfall indices and North Atlantic Oscillation. Results suggested negative, mainly statistically significant correlations at annual, winter and autumn scale.

scholarly journals Markov Chain Decomposition of Monthly Rainfall into Daily Rainfall: Evaluation of Climate Change Impact

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Chulsang Yoo ◽  
Jinwook Lee ◽  
Yonghun Ro
Keyword(s):  
Climate Change ◽  
Markov Chain ◽  
Rainfall Intensity ◽  
Transition Probabilities ◽  
Markov Chain Model ◽  
Daily Rainfall ◽  
Monthly Rainfall ◽  
Chain Model ◽  
Climate Change Scenarios ◽  
The Mean

This study evaluates the effect of climate change on daily rainfall, especially on the mean number of wet days and the mean rainfall intensity. Assuming that the mechanism of daily rainfall occurrences follows the first-order Markov chain model, the possible changes in the transition probabilities are estimated by considering the climate change scenarios. Also, the change of the stationary probabilities of wet and dry day occurrences and finally the change in the number of wet days are derived for the comparison of current (1x CO2) and 2x CO2conditions. As a result of this study, the increase or decrease in the mean number of wet days was found to be not enough to explain all of the change in monthly rainfall amounts, so rainfall intensity should also be modified. The application to the Seoul weather station in Korea shows that about 30% of the total change in monthly rainfall amount can be explained by the change in the number of wet days and the remaining 70% by the change in the rainfall intensity. That is, as an effect of climate change, the increase in the rainfall intensity could be more significant than the increase in the wet days and, thus, the risk of flood will be much highly increased.

scholarly journals Assessment of Rainfall Thresholds for Rain-Induced Landslide Activity in North Sikkim Road Corridor in Sikkim Himalaya, India

2019 ◽  
pp. 1-14 ◽  
Author(s):  
Bappaditya Koley ◽  
Anindita Nath ◽  
Subhajit Saraswati ◽  
Kaushik Bandyopadhyay ◽  
Bidhan Chandra Ray
Keyword(s):  
Rainfall Intensity ◽  
Lower Boundary ◽  
Daily Rainfall ◽  
Rainfall Threshold ◽  
Rainfall Data ◽  
Antecedent Rainfall ◽  
Rainfall Thresholds ◽  
Sikkim Himalaya ◽  
North East ◽  
The North

Land sliding is a perennial problem in the Eastern Himalayas. Out of 0.42 million km2 of Indian landmass prone to landslide, 42% fall in the North East Himalaya, specially Darjeeling and Sikkim Himalaya. Most of these landslides are triggered by excessive monsoon rainfall between June and October in almost every year. Various attempts in the global scenario have been made to establish rainfall thresholds in terms of intensity – duration of antecedent rainfall models on global, regional and local scale for triggering of the landslide. This paper describes local aspect of rainfall threshold for landslides based on daily rainfall data in and around north Sikkim road corridor region. Among 210 Landslides occurring from 2010 to 2016 were studied to analyze rainfall thresholds. Out of the 210 landslides, however, only 155 Landslides associated with rainfall data which were analyzed to yield a threshold relationship between rainfall intensity-duration and landslide initiation. The threshold relationship determined fits to lower boundary of the Landslide triggering rainfall events is I = 4.045 D - 0.25 (I=rainfall intensity (mm/h) and D=duration in (h)), revealed that for rainfall event of short time (24 h) duration with a rainfall intensity of 1.82 mm/h, the risk of landslides on this road corridor of the terrain is expected to be high. It is also observed that an intensity of 58 mm and 139 mm for 10-day and 20-day antecedent rainfall are required for the initiation of landslides in the study area. This threshold would help in improvement on traffic guidance and provide safety to the travelling tourists in this road corridor during the monsoon.

scholarly journals Spatial Interpolation on Rainfall Data over Peninsular Malaysia Using Ordinary Kriging

2013 ◽  
Vol 63 (2) ◽  
Author(s):  
Suhaila Jamaludin ◽  
Hanisah Suhaimi
Keyword(s):  
Spatial Analysis ◽  
Ordinary Kriging ◽  
Spatial Interpolation ◽  
Rainfall Intensity ◽  
Peninsular Malaysia ◽  
Rainfall Data ◽  
Kriging Method ◽  
Intensity Index ◽  
Dry Conditions ◽  
Two Indices

This study presents the spatial analysis of the rainfall data over Peninsular Malaysia. 70 rainfall stations were utilized in this study. Due to the limited number of rainfall stations, the Ordinary Kriging method which is one of the techniques in Spatial Interpolation was used to estimate the values of the rainfall data and to map their spatial distribution. This spatial analysis was analysed according to the two indices that describe the wet events and another two indices that characterize dry conditions. Large areas at the east experienced high rainfall intensity compared to the areas in the west, northwest and southwest. The small value that has been obtained in Aridity Intensity Index (AII) reflects that the high amount of rainfall in the eastern areas is not contributed by low-intensity events (less than 25th percentile). In terms of number of consecutive dry days, Northwestern areas in Peninsular Malaysia recorded the highest value. This finding explains the occurrence of a large number of floods and soil erosions in the eastern areas.

scholarly journals Estimating the Relative Uncertainties Sourced from GCMs and Hydrological Models in Modeling Climate Change Impact on Runoff

2012 ◽  
Vol 13 (1) ◽  
pp. 122-139 ◽  
Author(s):  
Jin Teng ◽  
Jai Vaze ◽  
Francis H. S. Chiew ◽  
Biao Wang ◽  
Jean-Michel Perraud
Keyword(s):  
Climate Change ◽  
Climate Change Impact ◽  
Daily Rainfall ◽  
Low Flow ◽  
Hydrological Models ◽  
Rainfall Runoff ◽  
Runoff Modeling ◽  
Change Impact ◽  
The Difference ◽  
Climate Series

Abstract This paper assesses the relative uncertainties from GCMs and from hydrological models in modeling climate change impact on runoff across southeast Australia. Five lumped conceptual daily rainfall–runoff models are used to model runoff using historical daily climate series and using future climate series obtained by empirically scaling the historical climate series informed by simulations from 15 GCMs. The majority of the GCMs project a drier future for this region, particularly in the southern parts, and this is amplified as a bigger reduction in the runoff. The results indicate that the uncertainty sourced from the GCMs is much larger than the uncertainty in the rainfall–runoff models. The variability in the climate change impact on runoff results for one rainfall–runoff model informed by 15 GCMs (an about 28%–35% difference between the minimum and maximum results for mean annual, mean seasonal, and high runoff) is considerably larger than the variability in the results between the five rainfall–runoff models informed by 1 GCM (a less than 7% difference between the minimum and maximum results). The difference between the rainfall–runoff modeling results is larger in the drier regions for scenarios of big declines in future rainfall and in the low-flow characteristics. The rainfall–runoff modeling here considers only the runoff sensitivity to changes in the input climate data (primarily daily rainfall), and the difference between the hydrological modeling results is likely to be greater if potential changes in the climate–runoff relationship in a warmer and higher CO2 environment are modeled.

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