Flood risk of today and tomorrow

Abstract

A flood is like a silent killer. Although small floods may appear harm less, they can be deadly when they become massive. For example, the an nual damages from flooding in Pontianak, Indonesia reached 30 million dollar in 2015 and could increase to 83.6 million dollar by 2055. To c ounter these events, we need to assess the vulnerability of a city by making a flood risk map and comparing the current vulnerability state in 2020 and the future vulnerability state in 2050. The present study involved quantitative research using variables and measurements to ind icate the vulnerability state of each district of Pontianak. The varia bles consisted of evacuation route efficiency and sheltering capacity, with these variables representing how easily people can be evacuated and the sufficiency of shelter, respectively. The efficiency of evacua tion routes was measured by integration measures from space syntax met hods, while sheltering capacity was determined by the data and simple equations. A quadrant diagram was used to record the results of both m easurements and present the vulnerability. This research projected the population in 2050 and repeated the measurements to predict future ch anges. By comparing the flood vulnerability of Pontianak City in 2020 and 2050, this research found that Pontianak City will become more res ilient against flooding. The reason for this finding is the implementa tion of a ring road to Pontianak City. The ring road will significantl y improve the evacuation route of the city. Howeover, the capacity rat e decreased, which should be addressed as a serious risk.