Flood monitoring and community based flash flood warning system for Nasiri River, West Seram, Maluku

ABSTRACT

On 1^st of August 2012, two successive flash floods hit Nasiri hamlet in Maluku archipelago, Indonesia. The floods destroyed 61 houses and swept some of them down into the sea. A monitoring and community-based early warning system (MCBEWS) was developed 2 years later. This paper presents the approach, development, and implementation of the system. There are two components, namely community capacity-building and the establishment of telemetric monitoring. The flood warning system considers two causes: extreme rainfall and landslide dam breaks. Raising awareness, workshops, training, and disaster organisation establishment appeared to effectively increase flood disaster preparedness capacity and community commitment. The adoption of a rainfall depth vs. intensity chart method for issuing flood warnings seems to be promising. The presence of an unusual flow reduction in the record during extreme rainfall indicates damming at the upstream of the record station due to landslides. Possible landslide dams near the downstream to the middle reaches might provide dangerous high peak discharge flash floods with short warning times.

KEYWORDS:

• Flood monitoring
• flood early warning
• community capacity-building
• telemetric system

Acknowledgments

This research was primarily supported by the internal UGM competitive research grant under the first Batch of the CaRED Programme (a collaboration between the MFAT of New Zealand and the Universitas Gadjah Mada). The authors appreciate the support and thank the staff who kindly delivered administrative assistance. The authors also appreciate the additional support of the Civil and Environmental Engineering Dept. Engineering Fac. of UGM Research Grant. Many thanks to Angga Primahessa and Andry Putra Styawan, who gave their thesis data access to support this research. The Community Service Institutions of UGM in sending students to Nasiri and neighbouring hamlets is highly appreciated. The authors would like to thank Mrs. Farida Salampessy, the Acting Head of Maluku PDMA in the study period, who facilitated communication to all the participating institutions in Maluku Province.

Disclosure statement

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

Additional information

Funding

This work was supported by the Universitas Gadjah Mada [No: 04/NZ/Dit-KA/2014].

Notes on contributors

Adam Pamudji Rahardjo

Adam Pamudji Rahardjo is an associate professor in hydraulics in the Department of Civil and Environmental Engineering, Engineering Faculty, Universitas Gadjah Mada. Currently, he is the chair of Master Program in Engineering in Natural Disaster Management. Several research projects and publications in sediment-related disaster have been conducted for the last ten years. Recent research is in flash flood early warning.

Joko Sujono

Joko Sujono is a professor of hydrology with more than 30 years of experience in water resources and hydrology. He has published a number of papers such as ”A comparison of techniques for hydrograph recession analysis” (2004) and the recent paper relating Water resource management strategy for urban water purposes in Dili Municipality, Timor-Leste (2020). Now, he is conducting research related to satellite-based rainfall in Indonesia.”