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

Arniza Fitri,Dian Pratiwi,Susarman Susarman,Adelia Agustina,H R Ali Salah,Galuh Pramita,Muhammad Shubhi Nurul Hadie,L Comfort,Fauzan Fauzan,I.W Sengara,S Saravanan

doi:10.1051/e3sconf/202133108006

Abstract

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.

Highlights

Flooding is the most frequent natural disaster that occurred in Indonesia in the past few decades, mostly triggered by extreme rain during the rainy season [1, 6]
One of the biggest flood events in the Cimadur river basin has been experienced in December 2019 which has caused damage and negative impacts to the local people and surrounding community
Due to the importance of flood peak discharges estimation in designing the engineering structures in the Cimadur river basin, this study aims to analyze the possibility of flood peak discharges in the catchment area of the

Summary

Introduction

Flooding is the most frequent natural disaster that occurred in Indonesia in the past few decades, mostly triggered by extreme rain during the rainy season [1, 6]. Regarding flood risk reduction and prevention in a local region, estimation of flood peak discharges in a local area is becoming necessary [9]-[11]. Estimation of the flood peak discharges could be helpful in properly designing the various engineering structures in the river basin [12, 15]. Cimadur river basin is one of the most important catchment areas in Lebak District, Banten Province, Indonesia. The land-use change activities such as converting the forest into residential areas and rice fields around the river have triggered the flood occurrences in this catchment for the past few years (Fig. 1). One of the biggest flood events in the Cimadur river basin has been experienced in December 2019 which has caused damage and negative impacts to the local people and surrounding community

Objectives

Methods

Results

Conclusion