scholarly journals Assessing Flood Risk of the Chao Phraya River Basin Based on Statistical Rainfall Analysis

2020 ◽  
Vol 15 (7) ◽  
pp. 1025-1039
Author(s):  
Shakti P. C. ◽  
Mamoru Miyamoto ◽  
Ryohei Misumi ◽  
Yousuke Nakamura ◽  
Anurak Sriariyawat ◽  
...  
Keyword(s):  
River Basin ◽  
Return Period ◽  
Flood Risk ◽  
Rain Gauge ◽  
Sustainable Growth ◽  
Type I ◽  
Type Iii ◽  
Pearson Type ◽  
Basin Scale ◽  
Chao Phraya River

The Chao Phraya River Basin is one of the largest in Asia and is highly vulnerable to water-related disasters. Based on rainfall gauge data over 36 years (1981–2016), a frequency analysis was performed for this basin to understand and evaluate its overall flood risk; daily rainfall measurements of 119 rain gauge stations within the basin were considered. Four common probability distributions, i.e., Log-Normal (LOG), Gumbel type-I (GUM), Pearson type-III (PE3), and Log-Pearson type-III (LP3) distributions, were used to calculate the return period of rainfall at each station and at the basin-scale level. Results of each distribution were compared with the graphical Gringorten method to analyze their performance; GUM was found to be the best-fitted distribution among the four. Thereafter, design hyetographs were developed by integrating the return period of rainfall based on three adopted methods at basin and subbasin scales; each method had its pros and cons for hydrological applications. Finally, utilizing a Rainfall-Runoff-Inundation (RRI) model, we estimated the possible flood inundation extent and depth, which was outlined over the Chao Phraya River Basin using the design hyetographs with different return periods. This study can help enhance disaster resilience at industrial complexes in Thailand for sustainable growth.

scholarly journals Analyses of flood peak discharge in Cimadur river basin, Banten Province, Indonesia

2021 ◽  
Vol 331 ◽  
pp. 08006
Author(s):  
Arniza Fitri ◽  
Muhammad Shubhi Nurul Hadie ◽  
Adelia Agustina ◽  
Dian Pratiwi ◽  
Susarman ◽  
...  
Keyword(s):  
River Basin ◽  
Return Period ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Rainfall Distribution ◽  
Flood Peak ◽  
Type Iii ◽  
Pearson Type ◽  
Catchment Areas ◽  
Peak Discharges

Cimadur river basin is one of the most important catchment areas in Lebak District, Banten Province. For the past few years, the catchment has experienced floods during the rainy season. The big issue of flooding has been recorded recently in December 2019 which has caused damage and negative impacts to the local people and surrounding community. This study aims to analyze the possibility of flood peak discharges in the catchment area of the Cimadur river. The flood discharges are calculated for 2, 5, 10, 25, 50, and 100 years return period based on the daily rainfall data from the year 2011 to 2020. The rainfall and land use data are obtained from PT Saeba Consultant. In this study, the hydrological analyses are including 1) analyses of average annual rainfall using the Thiessen method; 2) analyses of rainfall distribution and estimation of design rainfall by considering three methods involving: Log-Normal, Log Pearson Type III, and Gumbel Type 1; and 3) analyses of flood discharges by adopting Nakayasu Synthetic Hydrograph Unit (SHU). The rainfall distribution analyses show that the Log Pearson Type III provided the best fit. Based on the flood peak discharges analyses, the results show that the flood discharges for the 5, 10, 25, and 50 years return period in the Cimadur river basin are 470.71 m3/s, 560.16 m3/s, 698 m3/s, and 820.4 m3/s, respectively.

ESTIMATION OF THE T-YEAR SPECIFIC DISCHARGE USING THE REGIONALISED SKEWNESS COEFFICIENT OF THE LOG-PEARSON TYPE III DISTRIBUTION

2020 ◽  
Author(s):  
Jakub Mészáros ◽  
◽  
Pavol Miklánek ◽  
Pavla Pekárová ◽  
◽  
...  
Keyword(s):  
River Basin ◽  
Type Iii ◽  
River Region ◽  
Pearson Type ◽  
Skewness Coefficient ◽  
Distribution Parameters ◽  
Design Values ◽  
Specific Discharge ◽  
Morava River ◽  
Pearson Type Iii Distribution

In this paper the results are presented of estimation of T-year specific discharge of several streams in two regions in Slovakia. The Qmax time series used in the study were observed at water gauges from lowland Slovak part of the Morava River basin, and from the mountainous Belá River basin. For estimating the design values, we have studied the use of only one type of probability distribution, namely the Log-Pearson Type III Distribution (LP3 distribution). The use of only one type of distribution brings several benefits, e.g. possibility of the regionalization of the distribution parameters (in this study skew coefficient). In the first step the design values of the specific discharge series qmax (with historical data) were estimated and regional skew coefficients Gr of the LP3 distribution were computed. Regional skewness coefficient Gr was estimated to be 0.38 in the Morava River region, and 0.73 in the Belá River region. In many cases the estimate of the 1000-year specific discharge is two times higher than the value of the 100-year specific discharge. Then we have derived the empirical relations between station skew coefficient G and the elevation of the water gauge. In the second step we have derived the empirical relationships between 1000-years specific discharge q1000 and the elevation of the water gauge for both regions separately. The derived empirical regional equations can be used to estimate the 1000-years specific discharge of other streams in the region.

scholarly journals Analysing flood history and simulating the nature of future floods using Gumbel method and Log-Pearson Type III: the case of the Mayurakshi River Basin, India

2021 ◽  
Vol 19 (1) ◽  
pp. 43-69
Author(s):  
Aznarul Islam ◽  
Biplab Sarkar
Keyword(s):  
River Basin ◽  
Low Frequency ◽  
Flood Frequency ◽  
Flood Events ◽  
Significance Level ◽  
Type Iii ◽  
Return Probability ◽  
Pearson Type ◽  
Anderson Darling ◽  
Normally Distributed

AbstractFloods of the Mayurakshi River Basin (MRB) have been historically documented since 1860. The high magnitude, low-frequency flood events have drastically changed to low magnitude, high-frequency flood events in the post-dam period, especially after the 1950s, when the major civil structures (Massanjore dam, Tilpara barrage, Brahmani barrage, Deucha barrage, and Bakreshwar weir) were constructed in the MRB. The present study intends to find out the nature of flood frequency using the extreme value method of Gumbel and Log-Pearson type III (LP-III). The results show that the highest flood magnitude (11,327 m3 s−1) was observed during 1957–2009 for the Tilpara barrage with a return probability of 1.85% and the lowest (708 m3 s−1) recorded by the Bakreshwar weir during 1956–77 with a return probability of 4.55%. In the present endeavour, we have computed the predicted discharge for the different return periods, like 2, 5, 10, 25, 50,100, and 200 years. The quantile-quantile plot shows that the expected discharge calculated using LP-III is more normally distributed than that of Gumbel. Moreover, Kolmogorov–Smirnov (KS) test, Anderson–Darling (AD), and x2 distribution show that LP-III distribution is more normally distributed than the Gumbel at 0.01 significance level, implying its greater reliability and acceptance in the flood simulation of the MRB.

scholarly journals Cross-validating precipitation datasets in the Indus River basin

2020 ◽  
Vol 24 (1) ◽  
pp. 427-450 ◽  
Author(s):  
Jean-Philippe Baudouin ◽  
Michael Herzog ◽  
Cameron A. Petrie
Keyword(s):  
River Basin ◽  
Cross Validation ◽  
Rain Gauge ◽  
Reanalysis Data ◽  
Satellite Observations ◽  
Indus River ◽  
Mountain Areas ◽  
Temporal Representation ◽  
Basin Scale ◽  
Indus River Basin

Abstract. Large uncertainty remains about the amount of precipitation falling in the Indus River basin, particularly in the more mountainous northern part. While rain gauge measurements are often considered as a reference, they provide information for specific, often sparse, locations (point observations) and are subject to underestimation, particularly in mountain areas. Satellite observations and reanalysis data can improve our knowledge but validating their results is often difficult. In this study, we offer a cross-validation of 20 gridded datasets based on rain gauge, satellite, and reanalysis data, including the most recent and less studied APHRODITE-2, MERRA2, and ERA5. This original approach to cross-validation alternatively uses each dataset as a reference and interprets the result according to their dependency on the reference. Most interestingly, we found that reanalyses represent the daily variability of precipitation as well as any observational datasets, particularly in winter. Therefore, we suggest that reanalyses offer better estimates than non-corrected rain-gauge-based datasets where underestimation is problematic. Specifically, ERA5 is the reanalysis that offers estimates of precipitation closest to observations, in terms of amounts, seasonality, and variability, from daily to multi-annual scale. By contrast, satellite observations bring limited improvement at the basin scale. For the rain-gauge-based datasets, APHRODITE has the finest temporal representation of the precipitation variability, yet it importantly underestimates the actual amount. GPCC products are the only datasets that include a correction factor of the rain gauge measurements, but this factor likely remains too small. These findings highlight the need for a systematic characterisation of the underestimation of rain gauge measurements.

scholarly journals Possibility of reusing Al-Machraya River for feeding Hawizeh marsh

2018 ◽  
Vol 162 ◽  
pp. 03004 ◽  
Author(s):  
Mahmoud Al-Khafaji ◽  
Hayder Al Thamiry ◽  
Ala Al-Saedi
Keyword(s):  
Water Level ◽  
Distribution Patterns ◽  
Water Levels ◽  
Type I ◽  
Normal Type ◽  
Distribution Models ◽  
Type Iii ◽  
Tigris River ◽  
Pearson Type ◽  
Log Normal

Al Machraya River was considered as one of the water feeders of Hawizeh Marsh. In 1986, the outlet of this river into the marsh was blocked and the river was used as a main channel for the East Tigris Irrigation Project near Kalat Salih. This causes significant decrease in the available water supply sources, deterioration in the water quality distribution patterns and increasing the stagnation areas within the marsh. This research aims to study the possibility of reusing this river for feeding Hawizeh Marsh. A frequency analysis study was carried out to study the maximum and minimum probable water level (MMPWL) of Tigris River at the upstream of Kalat Salih Barrage. Six statistical models; Normal distribution, Log-Normal type II, Log-Normal type III, Pearson type III, Log- Pearson type III and Gumbel type I distribution were used to estimate the MMPWL. The results show that Pearson type III and Gumbel type I distribution models are the best to fit the maximum and minimum daily water level (WL), respectively, at the upstream of the Barrage. The estimated MMPWL were compared to the required WL in Hawizeh Marsh. The difference between Tigris River and Hawizeh Marsh water levels were found to be not operative to cause a significant flow toward the marsh. Therefore, Al Machraya River cannot be used to feed Hawizeh Marsh.

Flood Frequency Analysis of the Mahi Basin by Using Log Pearson Type III Probability Distribution

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Uttam Pawar ◽  
Pramodkumar Hire
Keyword(s):  
Probability Distribution ◽  
Frequency Analysis ◽  
Return Period ◽  
Flood Frequency ◽  
Flood Frequency Analysis ◽  
Series Data ◽  
Period Range ◽  
Type Iii ◽  
Pearson Type ◽  
Data Points

Flood frequency analysis is one of the techniques of examination of peak stream flow frequency and magnitude in the field of flood hydrology, flood geomorphology and hydraulic engineering. In the present study, Log Pearson Type III (LP-III) probability distribution has applied for flood series data of four sites on the Mahi River namely Mataji, Paderdi Badi, Wanakbori and Khanpur and of three sites on its tributaries such as Anas at Chakaliya, Som at Rangeli and Jakham at Dhariawad. The annual maximum series data for the record length of 26-51 years have been used for the present study. The time series plots of the data indicate that two largest ever recorded floods were observed in the year 1973 and 2006 on the Mahi River. The estimated discharges of 100 year return period range between 3676 m3/s and 47632 m3/s. The return period of the largest ever recorded flood on the Mahi River at Wankbori (40663 m3/s) is 127-yr. The recurrence interval of mean annual discharges (Qm) is between 2.73-yr and 3.95-yr, whereas, the return period of large floods (Qlf) range from 6.24-yr to 9.33-yr. The magnitude-frequency analysis curves represent the reliable estimates of the high floods. The fitted lines are fairly close to the most of the data points. Therefore, it can be reliably and conveniently used to read the recurrence intervals for a given magnitude and vice versa.

Impacts of Mid-Rainy Season Rainfall on Runoff into the Chao Phraya River, Thailand

2013 ◽  
Vol 8 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Shunji Kotsuki ◽  
◽  
Kenji Tanaka ◽  
Keyword(s):  
River Basin ◽  
Land Surface ◽  
Heavy Rainfall ◽  
Rain Gauge ◽  
Coefficient Of Determination ◽  
Necessary Condition ◽  
Surface Model ◽  
Chao Phraya River ◽  
June July

In Chao Phraya River basin, the runoff at the middle basin (Nakhon Sawan station: C.2 point) is important for the prevention of lower basin floods. Through analyzing 1980 to 2011 runoff and rain gauge data and performing numerical calculations using a hydrological land surface model, this study will describe a condition that causes massive floods at the C.2 point. The main conclusions are the following: (1) In 2011, precipitation exceeding the average by about 40% caused naturalized runoff +125% (+29 billion m3) that in an average year. The massive 2011 flood would have been difficult to prevent even if the operation of the Bhumibol Dam and Sirikit Dam had been appropriate. (2) In 1980, 1995, and 2006, precipitation exceeding the average by about 10% caused naturalized runoff exceeding that of the average year by 50 to 75%. The runoff rate in the Chao Phraya River basin is about 20%, and characteristically a minor increase in precipitation results in a considerable amount of runoff. (3) There are natural flood years, which have higher than average precipitation that causes massive floods, and there are non-natural flood years, which have high precipitation but nomassive floods. In natural flood years, the precipitation in June, July, and August is higher than that in the average years, and the total water storage capacity is brought close to saturation in September. Due to this, in addition to base runoff, surface runoff increases. (4) The coefficient of the determination of observed runoff from August to October is 0.6481 for rainfall from June to August and 0.5276 for rainfall from August to October. Heavy rainfall in June, July and August has the effect of bringing the soil close to saturation, which is a necessary condition for massive flooding. Massive flooding results if this necessary condition is met and there is heavy rainfall in September and October. This finding is also supported by a high coefficient of determination of 0.7260 between rainfall in May, June, July, August, September, and October and naturalized runoff in August, September, and October.

scholarly journals Analisis Debit Puncak Sungai Lubuk Banyau Kabupaten Bengkulu Utara Menggunakan Metode Hidrograf Satuan Sintetik

2020 ◽  
Vol 12 (2) ◽  
pp. 83-90
Author(s):  
Agam Sanjaya
Keyword(s):  
Return Period ◽  
Rainfall Intensity ◽  
Peak Discharge ◽  
Peak Time ◽  
Type I ◽  
Unit Hydrograph ◽  
Distribution Method ◽  
Pearson Type ◽  
Synthetic Unit Hydrograph ◽  
Log Normal

ANALISIS DEBIT PUNCAK SUNGAI LUBUK BANYAU KABUPATEN BENGKULU UTARA DENGAN MENGGUNAKANMETODE HIDROGRAF SATUAN SINTETIK Agam Sanjaya I1), Khairul Amri II2), Muhammad Fauzi III3) 1) 2) 3)Jurusan Teknik Sipil, Fakultas Teknik UNIB Jl. W.R. Supratman, Kandang Limun, Kota Bengkulu 38371, Telp. (0736)344087e-mail: [email protected], [email protected] , [email protected] aliran sungai (DAS) Sungai Lubuk banyau merupakan salah satu DAS yang berada di Bengkulu Utara. DAS Sungai Lubuk banyau mengalir dari daerah hulu yang terletak diwilayah Kabupaten Bengkulu utara. Tujuan dari penelitian ini adalah menganalisa debit puncak rencana akibat intensitas curah hujan pada DAS Lubuk Banyau dalam menganalisis hidrologi dengan menggunakan metode Hidograf Satuan Sintetik (HSS) Gama I, HSS Nakayasu dan HSS Snyder. Berdasarkan hasil perhitungan dari penelitian ini distribusi frekuensi terhadap tiga metode curah hujan, yaitu metode ditribusi Gumbel Tipe I, Log Pearson Tipe III dan Log Normal maka metode yang digunakan untuk perhitungan curah hujan rencana pada penelitian ini adalah Metode Gumbel Tipe I dengan periode ulang 2, 5, 10, 25, 50 dan 100 tahun, yaitu 181,164 mm, 275,356 mm, 337,709 mm, 416,518 mm, 474,974 mm dan 532,998 mm. Dari hasil analisis hidrologi pada penelitian diperoleh debit puncak pada DAS Lubuk Banyau untuk periode ulang 100 tahun dengan metode HSS Snyder adalah 1531,111 m3/detik dengan waktu puncak sebesar 5 jam merupakan debit puncak yang paling besar diantara HSS Gama I dan Nakayasu. untuk hasil debit puncak dengan metode HSS Gama I adalah 776,91m3/detik dengan waktu puncak sebesar 4 jam dan HSS Nakayasu 1023,87 dengan waktu puncak 2,46 jam. Maka didapatkan tinggi permukaan air pada DAS Lubuk Banyau yaitu 1,134 m.Kata kunci: hidrograf satuan sintetik, debit puncak, gama I, nakayasu, dan snyderAbstractWatershed Lubuk Banyau is one of the watersheds in North Bengkulu. The Lubuk River watershed flows from the upstream area located in the northern Bengkulu regency. The purpose of this study is to analyze the planned peak discharge due to rainfall intensity in the Lubuk Banyau watershed in analyzing hydrology using the Synthetic Unit Hydrograph (HSS) method of Gama I, HSS Nakayasu and HSS Snyder. Based on the results of calculations from this study the frequency distribution of three rainfall methods, namely the Gumbel Type I distribution method, Pearson Type III Log and Normal Log, the method used for calculating the planned rainfall in this study is the Gumbel Type I method with a return period of 2, 5, 10, 25, 50 and 100 years, namely 181,164 mm, 275,356 mm, 337,709 mm, 416,518 mm, 474,974 mm and 532,998 mm. From the results of the hydrological analysis in the study, the peak discharge in the Lubuk Banyau watershed for a 100-year return period with the Snyder HSS method was 1531,111 m3 / second with a peak time of 5 hours being the largest peak discharge between Gama I and Nakayasu HSS. for the peak discharge using the HSS Gama I method is 776.91m3 / sec with a peak time of 4 hours and Nakayasu HSS of 1023.87 with a peak time of 2.46 hours. Then the water level obtained at the Lubuk Banyau watershed is 1,134 m.Keywords: synthetic unit hydrograph, peak discharge gama I, nakayasu, and snyder.

scholarly journals Modelling the flood-risk extent using LISFLOOD-FP in a complex watershed: case study of Mundeni Aru River Basin, Sri Lanka

2015 ◽  
Vol 370 ◽  
pp. 131-138 ◽  
Author(s):  
G. Amarnath ◽  
Y. M. Umer ◽  
N. Alahacoon ◽  
Y. Inada
Keyword(s):  
Sri Lanka ◽  
River Basin ◽  
Rural Areas ◽  
Flood Risk ◽  
Flood Management ◽  
Flood Inundation ◽  
Protection Measures ◽  
Flood Risks ◽  
Basin Scale ◽  
Inundation Model

Abstract. Flood management is adopting a more risk-based approach, whereby flood risk is the product of the probability and consequences of flooding. Two-dimensional flood inundation modeling is a widely used tool to aid flood-risk management. The aim of this study is to develop a flood inundation model that uses historical flow data to produce flood-risk maps, which will help to identify flood protection measures in the rural areas of Sri Lanka. The LISFLOOD-FP model was developed at the basin scale using available historical data, and also through coupling with a hydrological modelling system, to map the inundation extent and depth. Results from the flood inundation model were evaluated using Synthetic Aperture Radar (SAR) images to assess product accuracy. The impacts of flooding on agriculture and livelihoods were analyzed to assess the flood risks. It was identified that most of the areas under paddy cultivation that were located near the middle and downstream part of the river basin are more susceptible to flood risks. This paper also proposes potential countermeasures for future natural disasters to prevent and mitigate possible damages.

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