scholarly journals Investigation of Trends, Temporal Changes in Intensity-Duration-Frequency (IDF) Curves and Extreme Rainfall Events Clustering at Regional Scale Using 5 min Rainfall Data

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2167 ◽  
Author(s):  
Bezak ◽  
Mikoš

High-frequency rainfall data is needed in different practical hydrologic applications, such as the construction of the intensity-duration-frequency curves (IDF). This paper presents an investigation of trends (station-wise and regional) for several rainfall durations that were constructed based on the 5 min rainfall data. Moreover, changes in IDF results for two 22-year sub-samples were also analyzed. Additionally, changes in extreme events clustering at the regional scale were also analyzed. Ten rainfall stations (44 years of data 1975–2018) located in Slovenia (central EU, approx. 20,000 km2) were used in this study. Results indicate that no clear pattern in the detected trends can be found based on the analyzed stations. However, all the statistically significant trends at the significance level of 0.05 for the 5 min rainfall data were negative. Moreover, regional trends for this duration were also statistically significant. The changes in the design rainfall events between two equal sub-samples (1975–1996, 1997–2018) were between −30% and 60%. The investigation of changes in extreme rainfall event clustering indicated that extreme 5, 30, and 60 min events could more frequently occur a few days earlier in spring or summer compared to the past period. On the other hand, longer duration events (i.e., 360 and 720 min) tend to more frequently occur a few days later in autumn compared to the past. In most cases, changes are not statistically significant.

2011 ◽  
Vol 24 (7) ◽  
pp. 1913-1921 ◽  
Author(s):  
Mateus da Silva Teixeira ◽  
Prakki Satyamurty

Abstract A new approach to define heavy and extreme rainfall events based on cluster analysis and area-average rainfall series is presented. The annual frequency of the heavy and extreme rainfall events is obtained for the southeastern and southern Brazil regions. In the 1960–2004 period, 510 (98) and 466 (77) heavy (extreme) rainfall events are identified in the two regions. Monthly distributions of the events closely follow the monthly climatological rainfall in the two regions. In both regions, annual heavy and extreme rainfall event frequencies present increasing trends in the 45-yr period. However, only in southern Brazil is the trend statistically significant. Although longer time series are necessary to ensure the existence of long-term trends, the positive trends are somewhat alarming since they indicate that climate changes, in terms of rainfall regimes, are possibly under way in Brazil.


Author(s):  
J. R. Santillan ◽  
A. M. Amora ◽  
M. Makinano-Santillan ◽  
J. T. Marqueso ◽  
L. C. Cutamora ◽  
...  

In this paper, we present a combined geospatial and two dimensional (2D) flood modeling approach to assess the impacts of flooding due to extreme rainfall events. We developed and implemented this approach to the Tago River Basin in the province of Surigao del Sur in Mindanao, Philippines, an area which suffered great damage due to flooding caused by Tropical Storms Lingling and Jangmi in the year 2014. The geospatial component of the approach involves extraction of several layers of information such as detailed topography/terrain, man-made features (buildings, roads, bridges) from 1-m spatial resolution LiDAR Digital Surface and Terrain Models (DTM/DSMs), and recent land-cover from Landsat 7 ETM+ and Landsat 8 OLI images. We then used these layers as inputs in developing a Hydrologic Engineering Center Hydrologic Modeling System (HEC HMS)-based hydrologic model, and a hydraulic model based on the 2D module of the latest version of HEC River Analysis System (RAS) to dynamically simulate and map the depth and extent of flooding due to extreme rainfall events. The extreme rainfall events used in the simulation represent 6 hypothetical rainfall events with return periods of 2, 5, 10, 25, 50, and 100 years. For each event, maximum flood depth maps were generated from the simulations, and these maps were further transformed into hazard maps by categorizing the flood depth into low, medium and high hazard levels. Using both the flood hazard maps and the layers of information extracted from remotely-sensed datasets in spatial overlay analysis, we were then able to estimate and assess the impacts of these flooding events to buildings, roads, bridges and landcover. Results of the assessments revealed increase in number of buildings, roads and bridges; and increase in areas of land-cover exposed to various flood hazards as rainfall events become more extreme. The wealth of information generated from the flood impact assessment using the approach can be very useful to the local government units and the concerned communities within Tago River Basin as an aid in determining in an advance manner all those infrastructures (buildings, roads and bridges) and land-cover that can be affected by different extreme rainfall event flood scenarios.


2020 ◽  
Vol 3 (1) ◽  
pp. 288-305
Author(s):  
Philip Mzava ◽  
Patrick Valimba ◽  
Joel Nobert

Abstract Urban communities in developing countries are one of the most vulnerable areas to extreme rainfall events. The availability of local information on extreme rainfall is therefore critical for proper planning and management of urban flooding impacts. This study examined the past and future characteristics of extreme rainfall in the urban catchments of Dar es Salaam, Tanzania. Investigation of trends and frequency of annual, seasonal and extreme rainfall was conducted, with the period 1967–2017 taken as the past scenario and 2018–2050 as the future scenario; using data from four key ground-based weather stations and RCM data respectively. Mann–Kendall trend analysis and Sen's slope estimator were used in studying changes in rainfall variability. Frequencies of extreme rainfall events were modeled using the Generalized Pareto model. Overall, the results of trend analysis provided evidence of a significant increase in annual and seasonal maximum rainfall and intensification of extreme rainfall in the future under the RCP4.5 CO2 concentration scenario. It was determined that extreme rainfall will become more frequent in the future, and their intensities were observed to increase approximately between 20 and 25% relative to the past. The findings of this study may help to develop adaptation strategies for urban flood control in Dar es Salaam.


Author(s):  
Vinicius Alexandre Sikora de Souza ◽  
Marcos Leando Alves Nunes ◽  
Sandra Ferronatto Francener ◽  
Ana Lúcia Denardin da Rosa

<p><span style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman','serif'; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-ansi-language: PT-BR; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Este estudo objetivou estimar a função Intensidade-Duração-Frequência (IDF) de eventos pluviométricos extremos a partir dos dados de precipitação das estações pluviométricas instaladas no estado de Rondônia, de modo que posteriormente tais informações possam ser utilizadas no dimensionamento de obras hidráulicas. Utilizou-se 41 estações pluviométricas com séries históricas acima de 10 anos, disponibilizadas pela Agência Nacional de Águas (ANA). Essas séries passaram inicialmente pelo teste de aderência Kolmogorov-Smirnov (KS), a fim de verificar o ajuste das mesmas as </span><span style="font-size: 12pt; line-height: 115%; font-family: 'Times New Roman', serif;">distribuições: Normal, Log-Normal, Exponencial, Gama, Gumbel, Weibull e Logística</span><span style="font-size: 12pt; line-height: 115%; font-family: 'Times New Roman', serif;">. O trabalho denotou que o teste de aderência </span><span style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman','serif'; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-ansi-language: PT-BR; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">Kolmogorov-Smirnov de forma geral forneceu uma expressiva aceitação na maioria das distribuições estatística testadas.</span></p><p> </p><p align="center"><strong><em>Analysis of fitness for extreme rainfall events in western amazon in static models: state Rondônia</em></strong></p><p> </p><p><strong>ABSTRACT: </strong>This study aimed to estimate the Intensity - Duration - Frequency (IDF) function extreme rainfall events from the data of precipitation of rainfall stations located in the State of Rondônia, so that such information can be later used in hydraulic structures. We used 41 rainfall stations with historical series over 10 years, provided by the National Water Agency (ANA). These series originally started by adherence Kolmogorov -Smirnov (KS) in order to check the fit of the same distributions: Normal, Log- Normal, Exponential, Gamma, Gumbel, Weibull and Logistics. Work denoted that the Kolmogorov - Smirnov test of adherence generally provided a significant acceptance in most of the tested statistical distributions.<strong></strong></p><p><span style="font-size: 12.0pt; line-height: 115%; font-family: 'Times New Roman','serif'; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-ansi-language: PT-BR; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"><br /></span></p>


Author(s):  
Indarto Indarto

This study aims to analyze trends,  shift and spatial variability of extreme-rainfall in the area of UPT PSDA Pasuruan. The daily rainfall data from 64 stations from 1980 until 2015 were used as main input. The 1-day extreem rainfall data is determined as the maximum annual of 24-hour rainfall events.  The statistical  analysis using Mann-Kendall, Rank-Sum, and Median Crossing Test using significance level α = 0,05. The spatial variability of extrem rainfall data is described using average annual 24-hour rainfall during the periods of record. Each station is represented by one value. The values are then interpolated using IDW interpolation methods to maps the spatial variability of extreem rainfall event.  The results show the value of statistical test for each stations that show the existing  trend, shift, or randomness of data. The result also produce thematic maps show the spatial variability of extreme rainfall and the value of each trend.


2020 ◽  
Vol 80 (3) ◽  
pp. 175-188
Author(s):  
R Rajkumar ◽  
CS Shaijumon ◽  
B Gopakumar ◽  
D Gopalakrishnan

In the present study, we examined the exposure of the Tamil Nadu region, India, to droughts and extreme rainfall events using the Standardised Precipitation Evapotranspiration Index (SPEI) and a classification scheme based on daily rainfall. We used high-resolution temperature and rainfall observations from the India Meteorological Department for the period 1951-2016. The robustness of the results was tested using the Mann-Kendall trend (M-K) test and the Kolmogorov-Smirnov (K-S) test. During the study period, there were statistically significant increasing trends in drought area (90% significance level), maximum drought intensity (99% significance level) and maximum drought severity (99% significance level) over the Tamil Nadu region. There has also been an increase in the frequency and intensity of heavy rainfall events in recent years. The spatio-temporal dimensions of this study suggest an increasing exposure of this semi-arid, rain shadow region to severe droughts and extreme rainfall events in recent decades. The results provide sufficient grounds to substantiate the necessity of immediate interventions at the policy level.


2021 ◽  
Vol 43 ◽  
pp. e30
Author(s):  
Nayara Dos Santos Albrigo ◽  
Maylla Tawanda dos Santos Pereira ◽  
Nelma Tavares Dias Soares ◽  
Gleibson De Souza Andrade ◽  
Vinicius Alexandre Sikora de Souza ◽  
...  

Information on extreme rainfall events associated with predictability and probabilities, especially in intensity-duration-frequency (IDF) curves, are essential for the development of engineering projects aimed at sanitation, drainage and waterproofing of surfaces, which allow to offer more suitable conditions for dimensioning hydraulic and hydrological works and services. However, much of the North Region of the country does not have this information available or updated. Thus, the objective of this study was to develop the IDF equation for the municipality of Cruzeiro do Sul - AC. A 14-year historical series was used, distributed between 1993 and 2011, such data were analyzed by the Gumbel distribution, the same being related, by means of the daily rain breakdown, for return periods comprising 2 to 100 years and rainfall durations of 5 minutes to 24 hours. In the analysis for the construction of the curve, it was observed that the years 1995 and 2002 corresponded to the years with the highest precipitated height indexes, being 111 mm and 103 mm, respectively, however these events had an estimated return time between 3 and 8 years, which does not denote anomalous events. The IDF curve constructed in the study showed good adherence to the observed data, which proves its use in the region.


2019 ◽  
Vol 12 (5) ◽  
pp. 1757
Author(s):  
Mariana Caroline Gomes de Lima ◽  
Thais Emanuelle Monteiro Dos Santos Souza ◽  
Valéria Sandra de Oliveira Costa ◽  
Carlos Eduardo Santos De Lima ◽  
Josimar Vieira Dos Reis ◽  
...  

A erosão hídrica é um dos grandes problemas que atingem regiões com potenciais agrícolas e áreas com propensão para deslizamento de terras. A chuva é considerada o fator climático que exerce maior influência no processo erosivo, especialmente nos trópicos por causa da sua distribuição temporal, espacial, características físicas e duração. Este trabalho teve como objetivo determinar o padrão hidrológico e o índice de erosividade  no sertão Pernambucano, visando contribuir com informações estratégicas para gestão agrícola e ambiental na região. Foram utilizados dados pluviométricos horários de 2000 a 2017 localizados no município de Petrolina, disponibilizados pela (APAC). A partir dos dados da precipitação, utilizou-se o aplicativo Climap 3.0 para avaliar os eventos extremos de precipitação e o padrão hidrológico, bem como determinou-se por meio de equações o índice de erosividade para a região. No período analisado os maiores valores da precipitação ocorreram entre os meses de janeiro e abril e identificou-se 8 anos consecutivos de seca na região. Os resultados apontam que houve tendências significativas nas séries de dados, a erosividade foi considerada fraca a moderada em sua maioria, e o padrão hidrológico mais frequente foi o padrão intermediário, resultando uma alta suscetibilidade dos solos da região em sofrer erosão hídrica.Evaluation of hydroclimatic pattern and erosivity Sertão of Pernambuco A B S T R A C T Water erosion is one of major problems affecting regions with agricultural potential and landslide-prone areas. Rain is considered the climatic factor that exerts greatest influence on erosive process, especially in tropics because its temporal, spatial distribution, physical characteristics and duration. This work purpose to determine  hydrological pattern and erosivity index in Pernambucano Sertão,  to contribute with strategic information for agricultural and environmental management in region. Rainfall data from 2000 to 2017 located in city of Petrolina, provided by (APAC) were used. From the rainfall data, the Climap 3.0  was used to evaluate the extreme rainfall events and  hydrological pattern, as well  to determine through equations the erosivity index for  region. During  analyzed period the highest rainfall values occurred between January and April and 8 consecutive years of drought were identified in region. The results indicate that there were significant trends in data series, erosivity was considered weak to moderate mostly, and most frequent hydrological pattern was the intermediate pattern, resulting in high susceptibility of region's soils to water erosion.Keywords: climate variability, hydrological pattern, extreme indexes.


2019 ◽  
Vol 5 (11) ◽  
pp. 2309-2317 ◽  
Author(s):  
Murphy Ponce Mohammed

The objective of the study is to create a flood hazard model of Tarlac River and to calibrate the model based on data gathered from the Philippine Atmospheric Geophysical and Astronomical Services Administration. The study employed analytical method wherein the 1D flood modeling was utilized. GIS, DEM data, rainfall data, river analysis system, HEC-GeoRAS, hydrologic modeling system, and HEC-GeoHMS were utilized. The different flood models revealed that Tarlac River is not expected to be overtopped by flood water as regards the different extreme rainfall events considered in the present study. The RAS model simulation was based on the concept that there is no base flow observed within the river reach before the occurrence of any extreme rainfall event. Henceforth, there is still no 100 percent assurance that the river reach will not be overtopped with the occurrence of initial base flow in combination with the occurrence of higher extreme rainfall events. Further studies or investigations should be delved into such combination of events. Possible levee breach of the Tarlac River as well as the possible incorporation of flood mitigating interventions in future modeling scenarios can be likewise considered.


Sign in / Sign up

Export Citation Format

Share Document