Ecosystem-based strategy against floods and droughts

For this research, there was a need for fine-scale risk maps that identify the current and predicted zones that, due to climate change, are most at risk of floods and droughts. Those maps would have to rely on existing hydrological models and climate change projections. UNDP-GEFD therefore requested technical support on the following aspects:

• Development of a methodology for identifying flood and drought risk due to climate change
• Assessment of the existing hydrological model
• Identification of current and future zones in the Xe Bang Hieng River Basin at risk of flooding and drought based on existing hydrological models
• Training and capacity building of key government officials

We produced flood hazard maps due to climate change using existing HEC-RAS and ISIS models for the Xe Bang Hieng river basin, which we updated with new, recent data. In addition, we analysed drought patterns to identify different return periods based on both historical data and extreme value analysis.

For the risk maps, we relied on existing flood and drought risk maps showing exposed areas for different scenarios. We combined this with asset maps of buildings and agricultural fields, and a vulnerability assessment resulting in damage curves of buildings and crop types.

Finally, we also assess the vulnerability of different sectors and stakeholders. Here, we always consider various factors such as meteorological drought, agricultural practices, socio-economic conditions and infrastructure resilience.