Attachments
Scenario and Disaster Impact Model (DIM)
Planning Scenario
Background
The Lao PDR is exposed to a range of climatic, hydrological, and geological phenomena that include floods, tropical storms, drought, heatwaves, landslides, disease outbreaks and epidemics, small earthquakes, and unexploded ordnance (UXO). Flooding is the country’s major natural hazard, with the Mekong River as its primary source. Seasonal flooding occurs each year in Lao PDR during the southwest monsoon season, from July to September. Flooding is a significant threat throughout much of Lao PDR. The most significant and prolonged flooding tends to occur in the central and southern provinces, but flash floods caused by tropical storms have also previously affected the northern provinces. The flooding often endangers lives and damages infrastructure, human settlements, and essential services. Rainfall trends indicate that the rainy season is starting earlier than usual, while climate-change induced weather events, such as more frequent and intense typhoons, are increasingly likely to have a greater impact on Lao PDR.
Planning Scenario
In this planning scenario, a major monsoon system moves into the southern region of Laos in late July, bringing with it prolonged heavy rainfall that lasts for several days. As the rainfall continues, the rivers in the affected region begin to overflow their banks, inundating surrounding areas with water and flooding low-lying areas. While all provinces in Laos are initially affected to some degree, the southern part of the country, in particular the provinces of Savannakhet and Champasak, are the most affected. The steep slopes and deep valleys of southern Laos caused water to flow rapidly downhill, leading to flash floods and landslides. In addition, the Mekong River, which runs through the region, was already at a high level due to heavy rainfall upstream in neighboring countries, exacerbating the impact of the local rainfall.
The combination of heavy rainfall, flash floods, and landslides in many areas causes significant damage to homes, infrastructure, and crops, and widespread disruption to transportation and daily life in the affected areas. As the rainfall continues, floodwaters in some areas rise to more than two meters high. Communities in low-lying areas and near rivers must evacuate their homes and seek shelter in temporary camps. However, many people are unable to leave their homes and become stranded, requiring rescue efforts.
In the initial days of the monsoon floods, more than 40 people reportedly lost their lives, most of them due to flash floods in the southern part of Laos, and over 20 people are missing. About 20,000 people were injured by the floods or when trying to hastily escape flooding areas. Over 830,000 people are affected across all provinces, and about 150,000 of the most vulnerable people are in need of humanitarian assistance, which includes 35,000 people who are displaced and hosted by relatives or informal and formal evacuation centers. In total, 7,500 houses were destroyed by the flood, and an additional 7,500 houses were damaged.
The immediate needs of the affected population are food, health, shelter, non-food items (NFIs) and water, sanitation, and hygiene (WASH). Several factors that increase the vulnerability of the population to flooding include high poverty rates, remoteness, rugged terrain, and inadequate infrastructure. Furthermore, many vulnerable communities are unaware of where to relocate during the floods. Government and Non-Governmental Organizations (NGOs) provided disaster risk reduction activities, including drills, in certain vulnerable communities, such as identifying safe areas for relocation in case of flooding. In the aftermath of the flood, displaced persons sought refuge in the homes of relatives in their own or neighboring villages or took shelter in schools, temples, or other localities.