Application of the Regional Flood Frequency Analysis to the Upper and Lower Basins of the Indus River, Pakistan

Abstract

The paper presents results of an application of the L-moments based regional flood frequency analysis to annual maximum peak (AMP) flows observed at seven stations (Tarbela, Kalabagh, Chashma, Taunsa, Guddu, Sukkur and Kotri) located on the main stream of the Indus River, Pakistan. The results of Run-test and lag-1 correlation coefficient showed that the data series at given sites is random and has no serious serial correlations respectively. Furthermore, the results of Grubbs and Beck test illustrated that there are no irregularities (abrupt variations) except low outlier(s) in the data series at various sites. To avoid their undue influence, these low outliers have been discarded and the sample information has been resummarized using the idea of left censored type A partial probability weighted moments. L-moments based regional heterogeneity measure (H) showed that the region, defined by seven stations, is heterogeneous; therefore, it has been sub-divided into two homogeneous regions (Region 1 and Region 2 consist of four (Tarbela, Kalabagh, Chashma and Taunsa) and three sites (Guddu, Sukkur and Kotri, respectively) using Ward's clustering method based on the site characteristics only. The results of various goodness-of-fit measures (L-moment ratio diagram, average weighted distance and Z DIST measures) showed that Region 1 has four candidates: generalized normal (GNO), generalized logistic (GLO), generalized extreme-value (GEV) and Pearson type III (PE3), while Region 2 has only one candidate; GLO, as regional distribution. Based on the results of different accuracy measures (regional average absolute relative bias, relative bias and relative root mean square error) of the estimated regional growth curves and quantiles, obtained from simulation experiments, PE3 is the robust distribution for Region 1, while for Region 2, GLO distribution can be used for the estimation of flood quantiles. Moreover, the results of the simulations study have been extended to obtain standard errors of the estimated quantiles at each site of the sub-divided homogeneous regions.

Application of the L-moments approach to the analysis of regional flood frequency in Northern Algeria

“…The IFM is commonly used to develop regional flood frequency models for ungauged or gauged sites where there is insufficient hydrological information to reliably estimate extreme events (Cunane 1987;Watt et al, 1989;Portela and Dias, 2005;Saf, 2009;Nyeko-Ogiramoi et al, 2012;Ellouze and Abida, 2008). Worldwide application of the L-moments method with the IFM in regionalisation studies of maximum flow rates has yielded very satisfactory results (Vogel and Fennessey, 1993;Madsen et al, 1997;Lim and Lye, 2003;Ferro and Porto, 2006;Ellouze and Abida, 2008;Saf, 2009;Mishra et al, 2009;Hussain, 2011). This is called an index-flood approach to regional frequency analysis (Dalrymple, 1960).…”

Flood frequency analysis using synthetic samples

“…Cunnane (1998) suggested using the station-year method, whereas Sveinsson et al (2001) proposed the population index flood method. The method introduced by Hosking and Wallis (1993) appears to display more acceptability in RFFA; its application can be found in Lim (2007), Saf (2009), Notto and Loggia (2009), Hussain (2011), and Rostami (2013.…”

Precipitation regional extreme mapping as a tool for ungauged areas and the assessment of climate changes

“…A number of studies have been conducted at various scales for basins with areas greater than several thousand square kilometre, e.g. the studies in the Wabash basin (Rao and Hamed, 1997) and the Montana area (Parrett, 1998) in the USA, in the Mahi-Sabarmati basin (Parida et al, 1998), in KwaZulu-Natal area in South Africa (Kjeldsen et al, 2002), in Sarawak basin of Malaysia (Lim and Lye, 2003), in the North-Bank of river Brahmaputra of India (Bhuyan et al, 2010), in the northern North Atlantic region (Kingston et al, 2011), in the Indus River basin of Pakistan (Hussain, 2011), in the West Coast of Peninsular Malaysia (Zakaria et al, 2012), in the Sicily island of Italy (Gabriele and Chiaravalloti, 2013) and in the Sefidroud basin of Iran (Dodangeh et al, 2014). Studies at country-scale with areas reaching 10 million km 2 have also been described and include, for example, Australia (Pearson et al, 1991), Canada (Adamowski et al, 1996), Israel (Ben-Zvi and Azmon, 1997), southern Africa (Mkhandi et al, 2000), Turkey (Seckin et al, 2011) and Selangor (Zakaria and Shabri, 2013).…”