Assessing community preparedness and household-level loss and damage of flood disasters in Katana DS Division, Gampaha District, Sri Lanka

Abstract

Floods are among the most frequent and damaging natural hazards in Sri Lanka, causing significant impacts to livelihoods, infrastructure, agriculture, and the local economy. The Katana Divisional Secretariat (DS) in the Gampaha District is particularly vulnerable due to its lowlying settlements and inadequate drainage systems. This study aimed to assess disaster risk, quantify household-level flood losses and damages, and evaluate community preparedness in the area, with the broader objective of informing flood risk management policies. Long-term daily rainfall data (1961–2024) from the Katunayake Meteorological Station were descriptively analysed using time-series plots to provide background context on rainfall variability and extreme events. Results indicated a significant increase in the frequency of extreme rainfall events exceeding 100 mm/day, particularly in the past three decades, while total annual rainfall remained relatively stable. A household survey (n = 200) was conducted using a stratified approach across four flood risk categories (high, moderate, low, and risk-free). Loss and damage data were analysed using ordinal logistic regression, which revealed that even low-risk and risk-free areas experienced unexpectedly high levels of loss. This was likely due to inadequate preparedness measures and limitations in early warning systems. Disaster preparedness was assessed through a Principal Component Analysis (PCA)–based Preparedness Index, focusing on household emergency planning and availability of emergency supplies. Subsequent multiple linear regression analysis demonstrated that preparedness levels were generally low to moderate, with households exhibiting higher preparedness reporting significantly fewer losses.