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.
