Vulnerability assessment of residential buildings to tidal flood hazards in Sriwulan Village, Sayung District, Demak Regency

Sani Afifah,Dyah Rahmawati Hizbaron,E Haryono,D Rahmawati Hizbaron,F Lavigne,B White,A Cardenas Tristan,R Che Omar,R Fitria Putri

doi:10.1051/e3sconf/202020001008

Abstract

Tidal floods are among the destructive hazards to coastal settlements. In December of 2017, extreme tidal floods impacted 3, 500 houses in Sriwulan Village, Sayung District, Demak Regency. This research was intended to (1) asses the vulnerability levels of the residential buildings and (2) analyze the most influencing factors. The assessment was based on the scenarios built with a 150cm-high tidal flood, as observed during the 2017 event and projected for the subsequent five years (2022). The Analytical Hierarchy Process (AHP) and Spatial Multi-Criteria Evaluation (SMCE) were used in four scenarios, namely, hazard, physical, environmental, and economic. The equal scenario was also developed as a comparison to the first four scenarios to achieve the second objective. Based on the physical, environmental, and equal scenarios, 22 houses distributed throughout most of the areas of Nyangkringan Sub-Village fell into the category of highly vulnerable. The most determinants of the vulnerability are related to the physical and environmental parameters. The former includes the design flood elevation, building maintenance, and building materials, while the latter consists of the source of tidal floods and their preventive measures, distance to water bodies, and accessibility.

Highlights

The Indonesian shore stretches as far as 81,000 km, constituting up to 14% of the total shoreline worldwide [1]
Fiftythree houses or 14% of the total samples fell into the category of low vulnerability because they were not flooded during a storm tide that led to 150cm-deep inundation
Based on the physical and environmental scenarios, 22 houses are highly vulnerable to tidal floods, creating a robust pattern

Summary

Introduction

The Indonesian shore stretches as far as 81,000 km, constituting up to 14% of the total shoreline worldwide [1]. With this condition, there are different threats to coastal areas, starting from erosion to floods, high waves, and even tsunamis. Locally known as rob, commonly take place in coastal lowlands, including Demak Regency that has been hit repeatedly by these disasters since the 1980s [2]. Sayung is the most severely affected district in the regency. It has a relatively flat morphology with altitudes in the range of 0-5 meters, which is partially responsible for the chronic flooding [4]

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Discussion

Conclusion