potential of social-ecological modelling to understand dynamics of pastoral land use under processes...
TRANSCRIPT
Potential of social-ecological modelling to understand dynamics of pastoral land use
under processes of change
Birgit Müller, Gunnar Dressler, Felix John
ADRAS-Workshop ILRI, June 2015
Content
1. Junior Research Group POLISES
2. Methods: Social-ecological modelling
3. Study 1: Stylized modelling study: Side effects of rain-index insurance on sustainable land use
Study 2: Polarisation between pastoralists
Study 3: Multi-agent model on pastoral land use of Borana
4. Further ideas for collaboration (Social networks, Board game on nomadic land use)
2/181 POLISES| 2 METHODS | 3 THREE MODELLING STUDIES| 4 FURTHER IDEAS
Junior Research Group POLISES: „Global food security policies and their social-ecological side effects in regions prone to global change”
Team: Head + 2 PhDs Postdocs, foreign fellowsDuration: Aug 2014 – July 2018 (+ 1 year)Funding: By German Ministry of Research (1.3 Mio €)
Objectives• explore the impacts of global food security policies on local land use
strategies• investigate the resulting social-ecological resilience of land users (in
particular pastoralists) in Africa• focus on combined effects of different processes of global change• advance the design of such policies to be appropriate for the most
vulnerable groups
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Global food security policies
Locally installed instruments to enhance food security
Environmental instruments
Land policies instruments
Instruments to cope with risk
Combined effects of global change (e.g. climate change, demographic change, environmental change)
Other land user
Pastora-list
Pastora-list
Natural resources
Loca
l Sys
tem
1
Mor
occo
, 2 E
thio
pia/
Keny
a
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5/18
Methodological approach
• Social-ecological modellingAgent-based modelling
• Modelling human decisions
• Social network analysis
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Methodological approach:Social-ecological modelling
1. Exploration of behaviour of social-ecological system in time and space
2. Including the feedbacks between the social and ecological components and understand mechanistic functioning
3. Virtual lab: Systematic analysis of combined effects of global change processes (turn processes on/off)
Stylized model / “Toy model”
4. Behaviour of land users can be modelled more realistically: adaptation, interaction, learning
Rule-based simulation models
Agent-based model
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Our modelling strategy: Start with simple model and add complexity step by step
Decision criteria /
strategy choice
Social-ecological system
ClimatePrecipitation
Institutions Insurances /
Access regimes / …
Technologies Trucks /
Fodder supplements /…
Livestock Sheep
Agents Pastoralist households
VegetationEcological Model
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Ecological submodelClimate
Vegetation
precipitationlognormal distribution
Livestock Sheep
green
biomass
reserve
biomass
growth
rain / grazing history
feeding reproductionforage
grazing
curr
ent
rain
fall
Ecological-economic study:Role of resting in rainy years• Natural insurance• Investment in the future
Müller et al. 2007 Agricultural Systems
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Fair insurance i - Payment of insuranceb - Insurance primep* - Strike level of insurance
z.B. wenn Regen unter 75% des langjährigen Mittels fällt
Without insuranceWith insurance
Opti
mal
frac
tion
of re
sting
α in
%
strike-level of the insurance in % of MAP
Results:1. The higher the strike level … the less resting … the lower the sustainability in the long-term
Müller et al. 2011, Ecological Economics2. If strike level low enough: Unintended side-effects avoided
ifif
Study 1: (Side) effects of index-insurances
One agent, homogeneous pastureDecision rules: Expected utility
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Study 2 - Polarisation: Multi-agent model
• Inspired by Moroccan case study
• Temporal structure: Discrete, yearly time steps, time horizon = 100 years
• Spatial structure: patch network on a hexagonal grid
• Dynamic feedback between ecological and economic component
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Study 2 – Polarisation: Approach
Diploma Thesis: Falk Hoffmann
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Stepwise add types of heterogeneity
0. Homogeneous rainfall1. Spatial heterogeneous rainfall
Agent heterogeneity:2. High / low mobility agents
(low costs / high costs)3. Plus different initial herd size4. Plus different initial cash savings
D. Kreuer
Study 2 - Polarisation: Results & Next steps
Case 1: If vegetation resilient Initial conditions of agents differ + different mobility costs
No polarisation
PolarisationCase 2: If vegetation less resilient Combined effect of heterogeneous mobility costs+ Heterogeneous initial herd sizes
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Currently carried out: Systematic sensitivity analysisNext step: Investigate measures against polarisation
Study 3: Multi-agent model on pastoral land use of Borana – Pastoralists
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Central village patch
Permanent remote patch
Dry season Rainy season
Herd movement
Once per season(4 seasons per year)
Dry season, if rain sufficient
Temporary remote patch
In cooperation with Russell Toth
Study 3: Multi-agent model on pastoral land use of Borana – Pastoralists
14/18
Model reproduces boom and bust cycles of herd sizes
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First version of index-insurance implemented
Study 3: Research questions for Borana model
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1. Under what conditions is mobile pastoralism sustainable, in the absence of insurance?
2. How does the uptake of insurance influence livestock numbers and vegetation conditions over the long term?
3. How does the design of the insurance influence uptake, and therewith the livestock numbers and vegetation conditions ?
4. What is the impact of change of weather conditions ( climate change) on these outcomes?
5. What is the impact of other institutional changes – e.g., land use restrictions?
R. Toth
Further research topics for collaboration
1. Crowding out of social networks by microinsurances
Abstract model: Use of social network analysis coupled with multi-agent model of pastoral
system
2. Educational games: Board game NomadSed
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NomadSed: A board game on sustainable land use of mobile pastoralists under global change
1. Educational purposes • Insights in coupling
environment & livelihood• Challenges of nomadic life
2. Science-society interface
Use of the game:
In cooperation with Vétérinaires sans Frontières Germany
Project days in schools„Long night of sciences“Exhibition at museum University education (national & international)
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Key messages
Use of stylized models not for predictionas tool for thinking, interdisciplinary communication and hypothesis testing:
• Rise awareness of unintended side effects• Inspire discussions with policy makers, insurers, scientists and other
stakeholders• Advice: If new policy instruments are designed – monitor impact on land use
strategies
Use of agent-based models:
• Include human-decision making in more realistic way than standard economic approaches incorporation of social learning, diffusion of innovations
• Explicit incorporation of feedbacks between socio-economic and ecological system components
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