Short comment on "The Kerala flood of 2018: combined impact of extreme rainfall and reservoir storage"

Abstract. Extreme precipitation events and flooding that cause losses to human lives and infrastructure have increased under the warming climate. In August 2018, the state of Kerala (India) witnessed large-scale flooding, which affected millions of people and caused 400 or more deaths. Here, we examine the return period of extreme rainfall and the potential role of reservoirs in the recent flooding in Kerala. We show that Kerala experienced 53 % above normal rainfall during the monsoon season (till August 21st) of 2018. Moreover, 1, 2, and 3-day extreme rainfall in Kerala during August 2018 had return periods of 75, 200, and 100 years. Six out of seven major reservoirs were at more than 90 % of their full capacity on August 8, 2018, before extreme rainfall in Kerala. Extreme rainfall at 1–15 days durations in August 2018 in the catchments upstream of the three major reservoirs (Idukki, Kakki, and Periyar) had the return period of more than 500 years. Extreme rainfall and almost full reservoirs resulted in a significant release of water in a short-span of time. Therefore, above normal seasonal rainfall (before August 8, 2018), high reservoir storage, and unprecedented extreme rainfall in the catchments where reservoirs are located worsened the flooding in Kerala. Reservoir operations need be improved using a skillful forecast of extreme rainfall at the longer lead time (4–7 days).

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Supplementary material to "The Kerala flood of 2018: combined impact of extreme rainfall and reservoir storage"

10.5194/hess-2018-480-supplement ◽

2018 ◽

Cited By ~ 2

Author(s):

Vimal Mishra ◽

Saran Aaadhar ◽

Harsh Shah ◽

Rahul Kumar ◽

Dushmanta Ranjan Pattanaik ◽

...

Keyword(s):

Extreme Rainfall ◽

Reservoir Storage ◽

Supplementary Material ◽

Combined Impact

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Significance of reservoir operation during extreme rainfall event in flood mitigation and water demand management in a metropolitan city of India: a case study

10.5194/egusphere-egu2020-6409 ◽

2020 ◽

Author(s):

Anandharuban Panchanthan ◽

Michele La Rocca ◽

Elango Lakshmanan

Keyword(s):

Water Supply ◽

Water Demand ◽

Reservoir Operation ◽

Extreme Rainfall ◽

Flood Mitigation ◽

Extreme Rainfall Events ◽

Rainfall Events ◽

Reservoir Storage ◽

Time To Peak ◽

Initial Storage

<p>Increasing water demand and climate change poses a great challenge in managing water resources availability. Reservoir operation during heavy rainfall events in an urbanized region is crucial in terms of decision making. The objective of this study is to assess the significance of reservoir operation during extreme rainfall events on flood mitigation and future domestic water supply. One of the major water supply reservoirs in Chennai city was chosen for this study. Rainfall record of recent four decades were analyzed and a major flood event occurred in 2015 was chosen. A combined model of hydrologic-hydraulic processes was carried out using Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS) and a box model based on input-output parameters. These models were calibrated and validated with historical flood events with good performance indications. Four different scenarios were framed for the analysis by targeting reduction in outflow and higher storage in the end of the event. Reducing the reservoir storage in advance and releasing with its maximum capacity at the beginning of the event will reduce the outflow from 5 to 27% and increase the time to peak by 11 to 16 hours. Available hydraulic facilities for higher storage at the end of the event were analyzed. It reveals that with the available facilities, reducing the initial storage from 75 to 50% will help to store 27 to 40% of inflow at the end of the event. Whereas the available hydraulic facilities will not allow to have a 75% of the reservoir storage at the end of this event. New gates can be provided for the safe operation during extreme rainfall events associated with the higher initial storage in the reservoir. Increased storage capacity combined with additional provisions of gates will reduce the outflow by 30% and increase the time to peak by 20 hours with the actual condition. By adapting these reservoir operation strategies, flood mitigation and fresh water augmentation during extreme events can be achieved to a significant extent. The developed combined modelling approach can be used to simulate various combinations of reservoir operations to assess the significance of timely decision on release during extreme rainfall events.</p><p>Keywords: flood mitigation, reservoir operation strategies, urban water supply, modelling</p>

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Modeling the concurrent impact of extreme rainfall and reservoir storage on Kerala floods 2018: a Copula approach

Modeling Earth Systems and Environment ◽

10.1007/s40808-019-00635-6 ◽

2019 ◽

Vol 5 (4) ◽

pp. 1283-1296 ◽

Cited By ~ 4

Author(s):

A. Anandalekshmi ◽

Seenu T. Panicker ◽

S. Adarsh ◽

A. Muhammed Siddik ◽

Sajna Aloysius ◽

...

Keyword(s):

Extreme Rainfall ◽

Reservoir Storage ◽

Copula Approach

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The Influence of Geographical Factors on Extreme Rainfalls in Lampung Province

Journal of Engineering and Scientific Research ◽

10.23960/jesr.v1i1.7 ◽

2019 ◽

Vol 1 (1) ◽

pp. 33

Author(s):

M Welly

Keyword(s):

Geographical Location ◽

Daily Rainfall ◽

Extreme Rainfall ◽

Design Flood ◽

Extreme Rainfall Events ◽

Rainfall Events ◽

Ungauged Basin ◽

Flood Discharge ◽

Design Rainfall ◽

Geographical Factors

Many people in Indonesia calculate design rainfall before calculating the design flooddischarge. The design rainfall with a certain return period will eventually be convertedinto a design flood discharge by combining it with the characteristics of the watershed.However, the lack of a network of rainfall recording stations makes many areas that arenot hydrologically measured (ungauged basin), so it is quite difficult to know thecharacteristics of rain in the area concerned. This study aims to analyze thecharacteristics of design rainfall in Lampung Province. The focus of the analysis is toinvestigate whether geographical factors influence the design rainfall that occurs in theparticular area. The data used in this study is daily rainfall data from 15 rainfallrecording stations spread in Lampung Province. The method of frequency analysis usedin this study is the Gumbel method. The research shows that the geographical location ofan area does not have significant effect on extreme rainfall events. The effect of risingearth temperatures due to natural exploitation by humans tends to be stronger as a causeof extreme events such as extreme rainfall.Keywords: Influence, geographical, factors, extreme, rainfall.

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Trend of Extreme Precipitations Indices in West-central Côte d’Ivoire: Case of the Lobo Watershed

European Journal of Engineering Research and Science ◽

10.24018/ejers.2020.5.10.2195 ◽

2020 ◽

Vol 5 (10) ◽

pp. 1281-1287

Author(s):

F. B. Allechy ◽

M. Youan Ta ◽

V. H. N’Guessan Bi ◽

F. A. Yapi ◽

A. B. Koné ◽

...

Keyword(s):

Cote D'ivoire ◽

Côte D’Ivoire ◽

Crop Yields ◽

Extreme Rainfall ◽

Cote D’Ivoire ◽

West Central ◽

Côte D'ivoire ◽

Northern Half ◽

Agricultural Potential ◽

Annual Total

The Lobo watershed located in the west-central part of Côte d'Ivoire is an area with high agricultural potential, influenced by climate variations and changes that reduce crop yields. The objective of this study is to analyse trends in ETCCDI extreme rainfall indices from rainfall data from 1984 to 2013 using ClimPACT2 software. This study shows that the trend of the indices: number of consecutive wet days (CWD), number of rainy days (R1mm) and the cumulative annual total rainfall (PRCPTOT) is decreasing. On the other hand, the number of consecutive dry days (CDD) is on the rise. In general, the whole basin has experienced a decrease in rainfall as well as wet sequences and an increase in dry sequences. These different trends observed in this study are more pronounced in the northern half of the watershed.

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Epigenetic factors and molecular markers of the risk of early pregnancy losses

GYNECOLOGY ◽

10.26442/20795696.2019.4.190523 ◽

2019 ◽

Vol 21 (3) ◽

pp. 9-16

Author(s):

Nataly I Frolova ◽

Tatiana E Belokrinitskaya

Keyword(s):

Early Pregnancy ◽

Genetic Factors ◽

Molecular Genetic ◽

Pregnancy Complication ◽

Common Complication ◽

Epigenetic Factors ◽

Genetic Determination ◽

Periconceptional Period ◽

Combined Impact

Background. Miscarriage is a common complication in early pregnancy. Current studies have shown a higher prevalence of miscarriage, ranging from 10 to 20%. The review is devoted to modern concepts of etiology and pathogenesis of early pregnancy losses. Aim. Assess the role of epigenetic factors and molecular-genetic markers in the pathogenesis and prediction of early pregnancy losses Materials and methods. In order to write this review domestic and foreign publications were searched in Russian and international search systems (PubMed, eLibrary, etc.) for the last 10-15 years. Relevant articles from the peer-reviewed literature and clinical practice guidelines were included. Results. Many recent studies have proved the contribution of various epigenetic factors to the pathogenesis of spontaneous miscarriages, and the molecular-genetic determination such kinds of pregnancy complication has been confirmed. Conclusion. The miscarriage in early gestation is driven by combined impact of epigenetic and molecular-genetic factors, as well as the presence of intergenic interactions. It is may lead to deterioration of physiological functions, and maternal pathologenic pathways could be changed as during her periconceptional period as so during the pregnancy.

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