1. Scenario Modeling for Ho Chi Minh City: Future Climate Risk Communication Through Simulation and Visualization Anond Snidvongs Southeast Asia START Regional Center Chulalongkorn University Bangkok, Thailand Nguyen Huu Nhan Southern Hydrometeorological Forecasting Center Ho Chi Minh, Viet Nam

2. Monsoon Driven Climate: PRECIS downscaled of ECHAM4 A2 and B2 GCM’s Storms: Modified Linda Sea Level: DIVA Hydrodynamic: HydroGIS Simulation and Modeling Tools Used A total of 27 scenarios

3. SCENARIOS INPUTSPURPOSES Seasonal Rainfall Extreme Rainfall Stor m Surge Mean Sea Level Upstream Inflow Landuse I.BL.0Baseline _Max No Baseline Extent and duration of the ‘regular’ seasonal monsoon floods with current landuse I.B2.0B2_MaxNo B2 2050 +24cm Baseline I.A2.0A2_MaxNo A2 2050 +26cm Baseline I.BL.1Baseline _Max No Baseline2050Extent and duration of the ‘regular’ seasonal monsoon floods with planned future landuse and flood control system I.B2.1B2_MaxNo B2 2050 +24cm Baseline2050 I.A2.1A2_MaxNo A2 2050 +26cm Baseline2050 I.BL.0_1Baseline _Max Baseline _30y No 100y2050Extent of the floods caused by 30y storm rainfall (but without storm surge) and 100y extreme upstream inflow; with planned future landuse and flood control system I.B2.0_1B2_MaxB2_30yNoB2 2050 +24cm 100y2050 I.A2.0_1A2_MaxA2_30yNoA2 2050 +26cm 100y2050

4. SCENARIOS INPUTSPURPOSES Seasonal Rainfall Extreme Rainfall Storm Surge Mean Sea Level Upstrea m Inflow Landuse II.BL.0Baseline_ Max Baseline_30yLindaNo100yBaselineExtent of the ‘extreme’ floods driven by combination of tropical storms (typhoons) surge, mean sea level rise, 30y rainfall and 100y upstream inflow; with current landuse II.B2.0B2_MaxB2_30yLindaB2 2050 +24cm 100yBaseline II.A2.0A2_MaxA2_30yLindaA2 2050 +26cm 100yBaseline II.BL.1Baseline_ Max Baseline_30yLindaNo100y2050Extent of the ‘extreme’ floods driven by combination of storms surge, mean sea level rise, 30y rainfall and 100y upstream inflow; with planned future landuse and flood control system II.B2.1B2_MaxB2_30yLindaB2 2050 +24cm 100y2050 II.A2.1A2_MaxA2_30yLindaA2 2050 +26cm 100y2050 II.BL.0_aBaseline_ Max NoLindaNoBaseline Extent of floods and saltwater intrusion caused by storm surge and sea level rise only in current landuse II.B2.0_aB2_MaxNoLindaB2 2050 +24cm Baseline II.A2.0_aA2_MaxNoLindaA2 2050 +26cm Baseline II.BL.0_bBaseline_ Max Baseline_30yNo 100yBaselineExtent of the floods caused by 100 y extreme upstream inflow and 30y storm rainfall (without storm surge) in current landuse II.B2.0_bB2_MaxB2_30yNoB2 2050 +24cm 100yBaseline II.A2.0_bA2_MaxA2_30yNoA2 2050 +26cm 100yBaseline

5. SCENARIOS INPUTSPURPOSES Seasonal Rainfall Extreme Rainfall Storm Surge Mean Sea Level Upstream Inflow Landuse III.bl.0Baseline_ Min No Baseline Extent of combination effect of drought and sea level rise on the water quality especially risk of salination under current land use III.B2.0B2_MinNo B2 2050 +24cm Baseline III.A2.0A2_MinNo A2 2050 +26cm Baseline I.BL.1_1Baseline_ Max Baselin e_30y No 100y2050Extent of floods driven by 30y rainfall, 100y upstream inflow and mean sea level rise; with planned future landuse and flood control system I.B2.1_1B2_MaxB2_30yNoB2 2050 +24cm 100y2050 I.A2.1_1A2_MaxA2_30yNoA2 2050 +26cm 100y2050

6. 3 and 5-days Extreme Rainfalls with 30 and 100 y Return Periods

7. DIVA Sea Level Projections

8. Linda PA2 Linda 1997 Linda PA1 Storm Scenarios

9. Fig 1. The effect of flood control system of HCMC for points inside flood protection area (example: District 1 of HCMC) Fig 2. The effect of flood control system of HCMC for points outside flood protection area (example: Sai Gon Main River)

10. No Dykes With Dykes