Flood hazard mapping of the Welang river, Pasuruan, East Java, Indonesia

Abstract

The availability of a flood hazard map is beneficial during flood risk reduction. However, there is a lack of high-resolution topographic data, which is a map realization obstacle. Therefore, this study aims to construct flood hazard maps based on hazard levels for various flood return periods. The 2D-hydrodynamic from the Hydrologic Engineering Center's River Analysis System (HEC-RAS) and Digital Surface Models (DSM) from Unmanned Aerial Vehicle (UAV) imagery were used for generating inundation maps. The results showed that simulation of return periods for 2 and 10 years illustrated a 37% increase in flood hazard levels. Furthermore, there was an increased danger level for locations that were exposed to flood inundation. This occurred in housing, some roads, and rice fields. Ultimately, this study mitigates flood hazards through the determination of evacuation directions, urban spatial planning, and informed flood mitigation measures.

KEYWORDS:

• Flood modeling
• hydraulic models
• unmanned aerial vehicle
• two-dimensional models
• velocity measurements
• flood risk

Acknowledgments

This study was funded by the Indonesian Ministry of Research, Technology, and Higher Education in 2020 through Graduate Study Grants. Significant data was provided by the Technical Implementation Unit of the Water Resource Management Agency (UPT PSDA) of Pasuruan Regency, Jawa Timur Province, Indonesia.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Entin Hidayah

Entin Hidayah Got his Bachelor Degree in civil engineering from Institut Teknologi Sepuluh Nopember Surabaya, Indonesia (1992), and has a Master of Urban Management (University of Canberra, Indonesia (2001). She has Doctoral in Civil Engineering (Institut Teknologi Sepuluh Nopember Surabaya, Indonesia (2011). She is working as a researcher and teacher at the University of Jember, Indonesia. Her areas of expertise include hydrology and hydraulic modeling, water resources management, and flood risk management.

Gusfan Halik

Gusfan Halik Got his Bachelor Degree in water resources engineering from University of Brawijaya (UB), Malang – Indonesia (1995), and has a Master Degree in Civil Engineering (Institut Teknologi Sepuluh Nopember Surabaya, Indonesia (2002). He got Doctoral Degree in Civil Engineering from (Institut Teknologi Sepuluh Nopember Surabaya, Indonesia 2016). He is working as researcher and teacher at Faculty of Civil Engineering of Jember, East Java, Indonesia (since 1999). Her areas of expertise include hydrology modeling, clmate change and data driven modeling.

Indarto Indarto

Indarto Indarto Got his Bachelor Degree in Agricultural Engineering from Gadjah Mada University (UGM), Yogyakarta – Indonesia (1995), and has a DEA in Water Science from University of Montpellier (USTL- Univerisite Science et Technique de Languedoc) in 1998. He got a Doctoral Degree from the ENGREF de Paris in 2002. He is working as a researcher at University of Jember, East Java, Indonesia (since 1995). His areas of expertise include hydrological modeling, application of GIS and RS in the area of agriculture and water resources management.

Dian Wahyu Khaulan

Dian Wahyu Khaulan Got his Bachelor Degree in Civil Engineering from University of Jember (UNEJ), Jember – Indonesia (2017), and has a Master Degree in Civil Engineering from the same University (2020). He is working as researcher Civil Engineering at Faculty of University of Jember, East Java, Indonesia (since 2020).