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

Abstract

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.

Generating Regional Models for Estimating the Peak Flows and Environmental Flows Magnitude for the Bulgarian-Greek Rhodope Mountain Range Torrential Watersheds

“…At some watersheds, the Q 25 , Q 50 , and Q 100 values computed by the LP-III distribution differ a little. Meanwhile in similar studies, such as in the Minab river at Iran [66] or the Mahi river in India [49], a similar small difference has been observed, which could be attributed to the fact that the discharge might be dominated by groundwater flows or the rain shadow effect. The observed and the predicted LP-III distribution annual peak discharges for all cases were observed to be fairly close to most of the data points.…”

“…The observed and the predicted LP-III distribution annual peak discharges for all cases were observed to be fairly close to most of the data points. For this reason, the predicted discharge values are likely to be quite reliable [49]. Figure 2 illustrates a reasonable fit between the observed and predicted LP-III distribution annual peak discharges for a random gauge, Velingrad.…”

“…It is to be noted that the aforementioned three parameters of the LP-III distribution are used to signify the mid-point, the slope, and the curvature of the magnitude frequency curve, respectively [49] Additionally, the flood magnitudes for the storm events occurring during different time periods can be computed by solving equations 4 and 5 [22].…”

Analyzing changes and frequency distribution in maximum runoff volumes with different duration of the Danube River at Bratislava

“…The Log-Pearson distribution type III. is used to estimate extremes in many natural processes and it is one of the most commonly used probability distribution in hydrology (Bobee, 1975;Pilon and Adamowski, 1993;Griffis and Stedinger, 2007;Pawar and Hire, 2018). In some previous works (Pekárová et al, 2018;Pekárová and Miklánek, 2019) we compared LPIII distribution with theoretical probability distributions, which were and still are also among the most used in Slovak hydrological practice.…”

Regional Flood Frequency Analysis using Dimensionless Index Flood Method

“…Even where gauging stations exists, intense flooding, poor planning and technological limitations lead to insufficient length of flood data due to faulty and dysfunctional gauging equipment [4]. The estimated flood quartiles of these sites are therefore based on large degree of extrapolation by simulation with associated high level of uncertainties [5]. In such cases, the widely used at-site flood frequency analysis is most preferred as historical flood records are drawn from a single site of interest.…”