A Flood Water Level and Risk Analysis in Langsa River Aceh Province

DOI

10.2991/assehr.k.210909.096How to use a DOI?

Keywords

flood water level, risk analysis, flood indunation and discharge, langsa river

Abstract

Langsa river that crosses the city during high rainfall often experiences flooding around the river’s border. This is due to the river which is not being able to accommodate the excess discharge so that the overflow of water has a negative impact on the facilities and infrastructure around the river. In addition, flooding is also affected by the damage of Langsa watersheds which is characterized by a decrease in the ability of storing the water. There are few information available regarding the high potential impact and inundation of floods in detail caused by flood discharge plan, so that this investigation aims to determine the height and inundation of floods for a return period of 5 and 100 years as a basic information in flood disaster mitigation in Langsa City. The scope of the analysis was carried out by several methods, namely the analysis of the maximum rainfall frequency distribution with the normal distribution method, log normal, log-Pearson type III, and Gumbel, periodic analysis of planned flood discharge with the Nakayashu Synthetic Unit Hydrograph method and analysis of water level and flood inundation with the help of HECRAS 5.01 and GIS software to encounter the risk of flood inundation of the stream. The results of this study denote that the flood discharge which occurs in the river due to the maximum daily rainfall (CH) based on the Gumbel distribution results in a flood discharge (Q5) of 361.21 m3/second with a water level of 1.0 meter. Meanwhile, the flood discharge (Q100) produces 564.65 m3/second with a flood water level of 3.0 meters and 33.86 square kilometers area of indunation. Moreover, with the availability of discharge information (Q100), it is predicted that 15 villages are potentially affected by flooding. The proposed analysis has auspicious value in the practical implementation of flood disaster mitigation in Langsa City.

Copyright

© 2021, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Download article (PDF)

TY  - CONF
AU  - Y. Ismida
AU  - F. Isma
AU  - H. Fajri
AU  - A. Zevri
PY  - 2021
DA  - 2021/09/11
TI  - A Flood Water Level and Risk Analysis in Langsa River Aceh Province
BT  - Proceedings of the 2nd International Conference on Science, Technology, and Modern Society (ICSTMS 2020)
PB  - Atlantis Press
SP  - 439
EP  - 446
SN  - 2352-5398
UR  - https://doi.org/10.2991/assehr.k.210909.096
DO  - 10.2991/assehr.k.210909.096
ID  - Ismida2021
ER  -