Flood Risk Assessment Focusing on Exposed Social Characteristics in Central Java, Indonesia

Abstract

This study analyzes Indonesia, a country marked by significant socioeconomic diversity, to inform the development of holistic flood risk management strategies. We examine the relationship between flood-exposed populations and socioeconomic factors at the regency level, particularly in Central Java, using open data encompassing flood-prone areas, topography, population distribution, and socioeconomic indicators. Key findings include population exposure to flooding varies significantly across the 33 regencies and 7 cities, ranging from 1% to 61% in exposure rate. A notable 5.8-fold difference in average income exists among regencies, with income strongly correlating with higher education rates. Similarly, poverty rates correlate with low educational attainment; there was a very large range in the balance between the size of the exposed economy and the number of exposed poor population in each administrative division. Consequently, we propose a classification system that considers social vulnerability due to poverty, low-education, and economic impacts. The map reflecting these classifications is a risk map that facilitates the understanding of the risk characteristics and the relative risk magnitude of each administrative district. Our analysis underscores the importance of adapting flood risk management strategies to local socioeconomic characteristics and suggests the importance of the use of local wisdom.