Mekong ARCC Climate Change Adaptation and Impact Study on Natural and Agricultural Systems

Task 2: Mekong ARCC Climate Change Impact and Adaptation

Study for natural and agricultural systems

May 2012, Vientiane

Aim

• The aim of Task 2 is to undertake a climate change impact and adaptation study on the water resources, food security, livelihoods and biodiversity of the Mekong River Basin

Objectives

1) identify vulnerabilities of rural poor and their environment to climate change vis-à-vis water resources, food security, livelihoods and biodiversity;

2) provide a scientific evidence base for the selection of case study sites;

3) identify adaptation strategies to inform development of community and ecosystem-based adaptation projects; and

4) inform policy makers, development specialists and the global climate science community on the impacts of climate change on water resources, food security, livelihoods and biodiversity of the Mekong Basin.

Phases, events & outputs

1. Inception 2. Zoning and trend analysis

3. Future climate

conditions and threats

4.Vulnerability assessment

5. Identify adaption options

6. Reporting

threat vulnerability adaptation

Baseline assessment & review of past studies

Basin & zone vulnerability assessment

Adaptation options by Zones

FINAL REPORT

Team working session

Inception workshop

Team working session

Vulnerability workshop

Team working session

Finalworkshop

Study technical team

Sector/theme working groups Sector/theme Members 1. Climate change, water

resources, modelling and GIS Tarek Ketelsen (lead), Jorma Koponen, Mai Ky Vinh, Oliver Joffre

2. Natural systems and biodiversity

Peter-John Meynell (lead), Nguyen Huu Thien, Sansanee Choowaew, Jeremy Carew-Reid,

3. Agriculture Oliver Joffre (lead), Dang Kieu Nhan, Bun Chantrea, Jorma Koponen

4. Fisheries and aquaculture Rick Gregory (lead) Truong Hoanh Minh, Chavalit Vidthayanon, Meng Monyrak

5. Livestock Rod Lefroy (remote participant) 6. Socio-economics and

livelihoods John Sawdon (lead), Try Thuon, Sengmanichanh Somchanmavong, Alex Kenny

National working groups Sector/theme Members 1. Cambodia Try Thuon (lead), Bun Chantrea, Meng Monyrak 2. Lao PDR Sengmanichanh Somchanmavong (lead) 3. Thailand Sansanee Choowaew (lead), Chavalit Vidthayanon 4. Vietnam Nguyen Huu Thien (lead), Dang Kieu Nhan, Truong Hoanh Minh,

Climate changes

Hydrological changes

Agricultural zones

Ecological zones

Species “zones”

Commercial crops

Subsistence crops

Traditional crops

Aqua-culture

Crop wild relatives

NTFPs Wild fish catch

Adaptation options

Wildlife Live- stock

Assessing climate change threats to agriculture and subsistence livelihoods

Agricultural systems and climate change continuum

CAM method

Source: ICEM, 2012

Key assessment concepts

Zones

• Climate change, Ecological, Agricultural

Shifts

• Geographic, Elevation, Seasonal

Hotspots

• Exposure, Sensitivity, Adaptive capacity

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Purpose of zoning is to: • Identify areas of the basin with common bio-physical and

socio-economic characteristics• Observe “shifts” in the zones with climate change

Three types of zones:

1. Climate change zones – temperature, rainfall and hydrology

2. Agricultural zones – agricultural land uses and natural conditions

3. Ecological zones – natural habitat, species and genetic resources

Climate change overlaid on “zones”

Zones provide the common analytical framework for the study team

Climate change zonesAreas experiencing

similar climate change

2050

Bioregions

Agriculture zones

Climate change shiftsRegular climate

1. Geographic shifts – change in area of suitability

2. Elevation shifts (for highly restricted habitats and species) – change in (i) location and (ii) elevation

3. Seasonal shifts – change in (i) yields, (ii) cropping patterns

Extreme events

4. Extreme event shifts Micro – eg flash flooding and soil loss in uplands Macro – eg saline intrusion in Delta; cyclone landfall

Geographic shift

Paddy rice and

commercial crops

Shift in zone of suitability for habitat and crops

Original extent of natural habitat

Remaining natural habitat

pockets

Subsistence crops and NTF collection

Elevation shifts2050

Seasonal shifts

Kratie

Increase in flood duration

Quicker onset of flood & shortening of transition season

Increase in flood magnitude& volume

Source: ICEM, 2012

Climate change “hot spots” – i.e. highly vulnerable areas

• High exposure: significant climate change relative to base conditions exposure to new climate/hydrological conditions

• High sensitivity: limited temperature and moisture tolerance range degraded and/or under acute pressure severely restricted geographic range rare or threatened

• Low adaptive capacity Poor connectivity Low diversity and tolerances Homogenous systems

THREATSClimate change

Climate and hydrological changes

Climate changes Regular (daily and seasonal)

Increase in C02 Change in temperature Change in rainfall

Extreme events

Storms Rainfall Wind Low pressure

Hydrological changes Regular (daily and seasonal)

Water availability Runoff and flow Regular flooding Evapotranspiration Saline intrusion Sea level rise

Extreme events Flooding (fresh and salt water) Flash flooding Drought Storm surge

SYSTEM ASSETS AND SENSITIVITY

Top commercial crops

Vietnam Laos Thailand Cambodia Rice, paddy Rice, paddy Rice, paddy Rice, paddy Coffee, green Maize Rubber Cassava Cashew nuts, with shell Coffee, green Cassava Maize Cassava Tobacco, Sugar cane Bananas

Fruit trees: Bananas and mangoes Vegetables: Sweet potatoes, tomatoes, beans, chilli

Traditional crop varieties Rice (more than 13,000

identified in Lao Eggplant (more than 3000

in Lao) Papaya Banana (centre of origin) Mango (centre of origin) Pineapple Water melon Passion fruits

Wild plants Cardamom, Rattan and bamboo Orchids Mushrooms Crop wild relatives Glutinous rice (centre of

origin Eggplant (centre of origin)

Subsistence crops Lowland and upland rice Cassava Maize Peanuts

Centre of origin for: coconut palm, sugarcane, clove, nutmeg, black pepper, onion, cucumber

System assets

Non cc drivers influencing agriculture trends

• future cropping patterns • area irrigated, • crop genetics, • farm mechanization, • farm employment, • fertilizer rates and pesticide use• Improved agronomic management• Infrastructure and accessibility

Sensitivity assessments: climate tolerances

Optimal growing conditions: Mean annual maximum temperature

Optimal growing conditions: mean annual precipitation

Key issues the team needs to resolve

• Deciding on the priority assets (i.e. species and habitats)

• Linking species to habitats• Dealing with ecosystem services• Knowing enough about species and habitat

tolerances to conduct the vulnerability assessment

TASK 2 APPROACHAssessment approach

CAM - Basin wide VA assessment framework

Key assessment methodologies & tools

CC modeling

Basin zoning

Basin land suitability

Hotspot crop yield modeling

GIS

An

alys

is

CLIMATE & HYDROLOGICAL MODELLING

Assessment approach

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Modelling options

VMOD

Mekong Delta 2008

(Aalto Uni & SEASTART)

Projections of future emissions and global GHG concentrations

IPCC EMISSION SCENARIOS

A1 B1 A2 B2

Downscaled projections of future climate at the basin-level

CLIMATE DOWNSCALING DYNAMICAL

(PRECIS) STATISTICAL PATTERN

Projections of future atmospheric climate, atmospheric & ocean dynamics

GCMs – GLOBAL CIRCULATION MODELS BCCR-BCM2.0

CCSM3 CGCM3.1 (T47)

CGCM3.1 (T63)

CNRM-CM3

CSIRO -MK3.0

ECHMA5/MPI-OM

ECHO-G

FGOALS-G1.0

GFDL-CM2.0

GFDL-CM2.1

GISS-AOM

GISS-EH

GISS-ER

INM-CM3.0

IPSL-CM4

MICROC3.2 (hires)

MICROC3.2 (medres)

MRI-CGCM2.3.2

PCM UKMO-HADCM3

UKMO-HADGEM1

VMOD Songkhram

2004 (Aalto Uni & SEASTART)

VMOD Mekong

Basin 2011 (Aalto Uni &

ICEM)

PRECIS Southeast Asia 2003

(SEASTART)

MRC DSS Mekong

Basin 2010 (MRC & IWMI)

SLURP Mekong

Basin 2011* (QUEST)

(no Mekong floodplain)

Vietnam 2009 (WeADAPT)

Mekong Basin 2009 (Cai et al, 2008)

Prediction of future hydrological regime HYDROLOGICAL MODELLING

CSIRO Mekong

Basin 2009 (18 sub-basins)

Approaches to modeling climate change: assessing future threat

• CC modelling:– allows for the

quantification of future climate change threats

– Is not perfect but is based on leading thinking on climate science

– Assesses the impact of changes in the global climate system to local areas of interest

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1. Projections of future emissions

2. Projections of future atmospheric and ocean dynamics

3. Downscaling projections to the Mekong Basin

4. Predicting future changes in the basin hydrological regime

5. Predicting future changes in the Delta floodplain environment & project

site

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Steps in the CC approach:1 - Selection of appropriate IPCC scenarios

Source: CSIRO, 2009

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Step 2: selection of appropriate GCMs

• Two earlier studies (Cao et al, 2009; Eastham et al, 2008) reviewed the performance of or used 17/24 IPCC AR4 GCMs for suitability to the Mekong region

• 6 were chosen based on their ability to replicate daily historical temperature and rainfall data

• In general, models perform better for temperature than precipitation

Climate model CO2 Scenario Abbreviation Data period Model resolution (degrees) CCCMA_CGCM3.1 A1b, B1 ccA, ccB 1850-2300 3.75° x 3.75° CNRM_CM3 A1b, B1 cnA, cnB 1860-2299 2.8° x 2.8° GISS_AOM A1b, B1 giA, giB 1850-2100 3° x 4° MIROC3.2Hires A1b, B1 miA, miB 1900-2100 1.1° x 1.1° MPI_ECHAM5 A1b, B1 mpA, mpB 1860-2200 1.9° x 1.9° NCAR_CCSM3 A1b, B1 ncA, ncB 1870-2099 1.4° x 1.4°

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Steps 3 – downscaling projections to the Mekong Basin

Purpose: reduce the geographical scope so that resolution can be improved

1. Statistical Assumes local climate is conditioned by large-scale (global)

climate but does not try to understand physical causality GCM output is compared to observed information for a

reference period to calculate period factors Period factors are then used to adjust GCM time-series

2. RCM (Regional Circulation Models) most sophisticated way to downscale GCM data Physically based 25-50km resolution Computationally intensive Requires detailed understanding of regional atmospheric and

ocean processes

3. Pattern-scaling Uses high resolution observation data to scale GCM data to

small areas or monitoring points Suitable when there is extensive observation data Cannot correct for statistical bias so should only be used to

assess relative changes

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Step 4 – Predicting future changes in the basin hydrological regime

• VMod model• area-based distribution of

hydro-meteorological impacts of climate change

• Computes water balance for grid cells ~3kmx3km

• Baseline 1981 - 2005• Can predict changes in:

– Rainfall– Runoff– Flows– Infiltration– evapotranspiration

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Step 5 – Predicting future changes in the flooding

• MIKE-11• Uses Vmod to establish

boundary conditions• Divides the floodplain into

zones (>120 in the delta)• Calculates small area water

balances – 25,900 water level points– 18,500 flow points

• Quantifies the changes in depth and duration of flooding due to changes in upstream hydrology and sea level rise Source: SIWRR, 2011

LAND SUITABILITY

Basin – crop suitability• Agro & eco zoning of basin characteristics• Historic suitability of basin for a range of

commercial and subsistence crops• Suitability with climate change• Assessment of transitions and shifts in

geographical and seasonal suitability

basin

target area

Predicting future changes in land suitability

Target areas – crop yields• Losses in crop yields within transition zones• Yield potential for new crops in transition

zones

Predicting future changes in land suitability

LUSET – Land use suitability evaluation tool• Developed by IRRI • evaluates the suitability of each land unit (grid cell)

for a single type of land use type (single crop). • based on crop requirement, climate, terrain and soil

characteristics. • Allows for assessing changes in temperature and

rainfall before aggregating suitability

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Crop requirement: Terrain (slope and drainage)

Crop requirement: Soil characteristics (pH, soil

texture, soil depth, base saturation)

Crop requirement: Water, temperature

Land characteristic: Terrain (slope and

drainage)

Land characteristic: Soil characteristics (pH, soil

texture, soil depth, base saturation)

Land characteristic: Irrigation

Land characteristic: Meteorological

characteristics (rainfall, temperature)

Terrain suitability value

Combined weighted suitability value

Soil characteristics suitability value

Water, temperature suitability value

Suitability class table and GIS layer

Lowland rice

upland rice

cashew

cashew

rubber

Coffee (coffea canephora)

cassava

Black pepper

Maize

CROP YIELD MODELLING

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Predicting future changes in agricultural productivity

AquaCrop• Crop productivity model developed

by FAO• Water driven

– quantifies the relationship between crop growth/biomass and crop transpiration

• Changes in yield compared to reference/ideal conditions for a given crop

• emphasizes the fundamental processes involved in crop productivity and the responses to water deficits,

• Can also factor in CO2 concentrations

Source: FAO, 2010

Maize growth cycle

AquaCrop• Assesses water

requirements at each growth phase relative to a reference norm and quantifies changes in biomass => yield

Source: FAO, 2010

Establishment | Vegetative | Flowering |yieldFormation | Ripening | Maturity

Reduction in max canopy cover

Delay in time to reach max canopy cover

Decline in canopy cover during productive phases (yield formation/ ripening)

Source: FAO, 2010

ADAPTATION

Adaptation in zones, habitats and species

Adaptation in vulnerable (hot spot):• agriculture zones• ecozones• habitats• species:

Industrial/commercial crops Subsistence crops Traditional crops Crop wild relatives NTFPs

Adaptation

Addressing the adaptation deficit