Technical Report in Supporting for Modelling and Development of Risk Maps in Lao PDR
This technical report provides a high-resolution spatial analysis of climate-change-induced flood and drought risks within the Xe Bang Hieng River Basin and Luangprabang City. Developed as a cornerstone of the IWRM-EbA project, the study utilizes the IPCC Sixth Assessment Report (AR6) framework to integrate sophisticated hydraulic modeling with socio-economic vulnerability data. By employing SWAT and HEC-RAS modeling tools, the researchers successfully simulated flood scenarios for various return periods, notably validating the technical outputs against the historic 2019 flood event to ensure regional accuracy.
A critical finding within the report is the projected impact of the RCP 8.5 climate scenario, which suggests that extreme flooding events currently categorized as 50-year occurrences may increase in frequency to become 10-year events by the mid-21st century. Beyond flooding, the document assesses meteorological and agricultural drought through the Standardized Precipitation Index. The results highlight a distinct regional variation in risk, noting that while the western plains face long-term agricultural threats, the upstream eastern regions are highly susceptible to shorter, intense dry periods that disrupt local ecosystems.
The analysis culminates in a detailed mapping of village-level exposure, specifically identifying significant economic risks to essential crops such as rice and maize. By calculating the intersection of hazard probability and community vulnerability, the report serves as a vital decision-support tool for district authorities. It provides the evidence base necessary for implementing targeted ecosystem-based adaptation strategies and nature-based solutions, ultimately aiming to strengthen the climate resilience of vulnerable populations across the target river basins.