Theme 2: Climate change impacts on flood and drought and their consequences in agriculture.

A Case Study on Investigating the climate change impact on flooding in the Sittaung river basin

Su Su Kyi - Department of Meteorology and Hydrology Dr. Mohamed Rasmy –ICHARM Prof. Toshio Koike - ICHARM

Mohamed Rasmy Senior Researcher/Associate Professor PWRI/ICHARM Agriculture in Myanmar is one of the few developing nations to be a net exporter of food, which accounted for ü 20% of its foreign exchange earnings ü Agriculture generated roughly 2/3 of employment ü 42% of the recorded GDP

ü farmers rely on the monsoon season as their primary water source and are subject to the recent fluctuating/changing weather patterns.

ü Eg. Rice crop was negatively affected by a record high rainfall during the prolonged 2011 monsoon season which resulted in a projected 10 percent drop in production.

ü Addressing climate change and its impact on agriculture is one of the top most priority in Myanmar

http://dwms.fao.org/atlases/myanmar/downs/atlas/p025_netso wnarea_map.pdf History of Disasters Major disasters:

• 2006 Apr Cyclone Mala • 2008 May Cyclone Nargis • 2010 Oct Cyclone GIRI • 2011 Mar Tarlay Strong Earthquake • 2011 JJA Heavy Rain & Floods • 2011 Oct Pakokku Flash Flood • 2012 JJA Lower/NE Myanmar Floods • 2012 Nov Shwebo Strong Earthquake • 2013 May Cyclone Mahasen • 2013 J-O Heavy rain triggered secondary hazards. • 2015 July Cyclone Komen, Heavy Rain & Floods • 2016 July Heavy Rain & Floods Map of disaster prone areas Investigating the impact of climate change on flooding in the Sittaung river basin

Basin Characteristics Catchment Area - 34, 450 Km2 (4th Largest River Basin in Myanmar) Main River Length - 422 km Population - 3.92 million (2014 Census)

Madauk

Sittaung River Basin (Dams and Hydro-Met stations) Objectives of the Study Ø To analyze hydrological responses of the past flood events (2012 - 2015) using RRI model Ø To analyze change in precipitation and river flows under future climates Ø To propose the development of the countermeasures Investigating the impact of climate change on flooding in the Sittaung river basin (Contd.)

Present Conditions Future Conditions Global Climate Model (GCM)

Global Topography Data Downscaling & Observed Rainfall (DEM, ACC, DIR) Bias-Correction Observed RRI Model Setup Discharge and Simulation Present Future Climate Climate MODIS Image Calibration/Validation

Flood Inundation Map

Countermeasure Change of Floods severity and occurrence Structure & Non- between present and future climates structure

Effective Management for Floods in the Sittaung River Basin Investigating the impact of climate change on flooding in the Sittaung river basin (Contd.) - Present Condition Analysis of hydrological responses of the past floods (2012 - 2015) using RRI model Comparison of simulated discharge with and without dam Comparison of flood Comparison of Withoutboundary dam Boundary conditions Condition & With (2012 Dam Boundary Flood) Condition (2012) inundation (2015 Flood) 6000 0 5000 30 Max. Rainfall-127mm RRI MODIS 4000 60 2 year return period Model Image 3000 90 2000 Station 120 1000 150 Rainfall(mm) Discharge (m3/s) Discharge 0 180 1-Jul-12 1-Jan-12 1-Jun-12 1-Oct-12 1-Feb-12 1-Sep-12 1-Apr-12 1-Dec-12 1-Mar-12 1-Aug-12 1-Nov-12 1-May-12

Source: Myanmar Information Basin Average Rainfall10 Years Observed Discharge (m3/sec) Simulated50 Years Discharge (with boundry)(m3/sec) Simulated100 Years Discharge(without boundary)(m3/s) Source: MyanmarManagement Information Unit (MIMU) Management Unit (MIMU)

Flood Hazard Maps Myanmar Information Management Unit (MIMU) 10-year Flood 50-year Flood 100-year Flood

Source: Myanmar Information Management Unit (MIMU) Investigating the impact of climate change on flooding in the Sittaung river basin (Contd.) – Future Present Condition Analysis of changes in precipitation and river discharge under climate change

Five GCMs output of CMIP5 (Coupled Model Inter Comparison Project) were selected for study: (1) CNRM-CM5, (2) GFDL-CM2, (3) CanESM2.1, (4) MIROC5, (5) MPI-ESM-MR Ø Present Climate: 1990-2005 (16 Years) Ø Future Climate: 2046 to 2061 (16 Years)

Comparison of precipitation Comparison of simulated discharge at Madauk Station between several model outputs from CMIP5 canESM2 CNRM-CM5 MIROC5 (CMIP5: Coupled Model Inter comparison Project Phase-5) 7500 canESM2 8000 CNRM-CM5 8000 MIROC5 7000 6500 7000 6000 6000 5500 Monthly corrected rainfall (Future) 5000 5000 4500 4000 4000

3500 3000 3000 0 10 20 30 40 0 10 20 30 40 0 10 20 30 40 Rank Rank Rank CanESM2(Past)3 CanESM2(Future)3 CNRM-CM5(Future) CNRM-CM5(Past) MIROC5(Future) MIROC5(Past) Rainfall intensity GFDL-CM3 MPI-ESM_MR GFDL-CM3 8000 MPI-ESM_MR will be increased 8000 7000 7000 in future 6000 6000 5000 5000

4000 4000 (mm/Day) 3000 3000 0 5 10 15 20 25 30 35 40 0 5 10 15 20 25 30 35 40 Average RainfallAverage Rank Rank GFDL-CM3(Future) GFDL-CM3(Past) MPI-ESM-MR(Future) MPI-ESM-MR(Past) Red-dashed line: Future Climate(2046-2061) Black line: Present Climate (1990-2005) Investigating the impact of climate change on flooding in the Sittaung river basin (Contd.) Analysis of effectiveness of structural countermeasures (Dam, Embankment) using RRI model

Case-1: New embankment Without With 50-year Ø Construction of 3.0 m high embankment along the Embankment Embankment Flood bank of river from Madauk Township to the river outlet

Madauk Township

Outlet Point

Case-2: New Dams Ø Construction of dam near the Taungoo station in the With Dam Embankment & upstream area and station Dam Propose Dam 50-year Locations Flood Dam-1 Assuming dam capacity: Dam-1= 1006.5x 106 m3 Dam-2 = 808.7 x 106 m3 Dam-2 Theme 2: Climate change impacts on flood and drought and their consequences in agriculture.

Framework for Assessing Flood, drought & Climate Change Impacts on Agriculture

Mohamed Rasmy Senior Researcher/Associate Professor PWRI/ICHARM Structure of RRI Model

Input Subsurface + Surface Output Rainfall 1D Diffusion in River Discharge DEM W. Level Land Cover

2D Diffusion Inundation in Catchment Cross Sec. Vertical Infiltration

• Two-dimensional model capable of simulating rainfall-runoff and flood inundation simultaneously • The model deals with slopes and river channels separately • At a grid cell in which a river channel is located, the model assumes that both slope and river are positioned within the same grid cell

Sayama, T. et al.: Rainfall-Runoff-Inundation Analysis of Pakistan Flood 2010 at the Kabul River Basin, Hydrological Sciences Journal, 57(2), pp. 298-312, 2012. WEB-RRI: Coupling Hydro-Sib-RRI with RRI Model

Energy and Vertical Water flux Soil moisture Balance Profile

River Routing

Surface flow

River flow - 1D Lateral flow-2D Diffusion wave Diffusion wave

Slope-River GW-River GW-Soil Moisture Interaction Interaction Interaction Ground water Flow

11 Simulation Model for Rice-Weather Relations

Overview of simulation model of the SIMRIW model developed by Prof. Horie (1987)

SIMRIW predicts the potential yield that can be expected from a given cultivar under a given climate Framework for Assessments of Climate Change Impacts on Agriculture

Daily ground MODIS 8-daily LAI rainfall data & FPAR data Irrigation Rice CMIP-5 Climate Past-Climate Data Practices Type Projection Data (Observation) Meteorological DEM, soil, and forcing data (JRA-55) land-use data

Model Calibration & Validation using WEB-RRI Model Coupled with discharge data & Yield SIMRIW

Simulated Rice Production Scenarios for Crop PALSAR-2 & INAHOR Water Allocation for floods, drought. Scenarios type/calendar Climatology Change

Climate Change & Adaptability Impacts on Economy INternational Asian Harvest mOnitoring system for Rice (INAHOR) Thank you for your kind attention !!!