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Application of a Spatially Explicit Bio-physical Crop Model to Assess Drought Impact on Crop Yield and Crop-Drought Vulnerability in Sub-Saharan Africa

Applicant Yang Hong
Number 146430
Funding scheme Interdisciplinary projects
Research institution EAWAG Systems Analysis, Integrated Ass. & modeling
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Environmental Research
Start/End 01.12.2013 - 30.11.2017
Approved amount 241'906.00
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All Disciplines (6)

Discipline
Environmental Research
Social geography and ecology
Hydrology, Limnology, Glaciology
Economics
Biophysics
Meteorology

Keywords (1)

drought, food security, crop model, vulnerability

Lay Summary (German)

Lead
Dürren können verheerende Auswirkungen auf Wasserversorgung, landwirtschaftliche Produktion, Ernährungssicherung und zahlreiche andere Aspekte der menschlichen Existenz haben. Die Auswirkungen sind besonders stark im sub-Saharischen Afrika (SSA), wo regenbewässerte Subsistenzlandwirtschaft die Nahrungsmittelproduktion dominiert und politische, soziale sowie wirtschaftliche Systeme oftmals unzureichend darauf vorbereitet sind, Katastrophen zu bewältigen.
Lay summary

Anwendung eines räumlich expliziten,bio-physikalischen Pflanzenwachstumsmodells zur Abschätzung vonDürreauswirkungen auf Ernteerträge und pflanzliche Dürreanfälligkeit imsub-Saharischen Afrika

Inhalt und Ziel des Forschungsprojekts

Das vorgeschlageneProjekt hat drei Ziele: 1) Die Simulation der Auswirkung historischerDürreperioden auf landwirtschaftliche Erträge, inklusive Dauer und Zeitpunkt inder Wachstumsperiode, mittels Anwendung des GIS-basiertenPflanzenwachstumsmodells GEPIC; 2) Erfassung der Dürreanfälligkeit landwirtschaftlicherPflanzen durch Vergleich von Ertragseverlusten (simuliert), relativen Verlustenim Produktionsvolumen (Statistiken) sowie der Häufigkeit von Dürreereignissen(identifiziert); 3) Untersuchung von sozio-ökonomischen Faktoren, die dieDürreanfälligkeit landwirtschaftlicher Pflanzen beeinflussen sowie dieräumliche Identifikation von "hot spots“ hoher Dürreanfälligkeit in SSA.

Wissenschaftlicher und gesellschaftlicherKontext

Das vorgeschlageneProjekt wird die Anwendbarkeit landwirtschaftlicher Modelle zur Abschätzung vonDürreauswirkungen auf Ernteerträge und von Dürreanfälligkeiten verbessern, undgleichzeitig verbleibende Einschränkungen aufzeigen. Durch das Bereitstellenintegrierter bio-physikalischer und sozio-ökonomischer Auswertungen hilft dieStudie, Ansatzpunkte zur Entwicklung effektiver Massnahmen zur Bewältigung vonDürren in SSA zu identifizieren. Die Informationen aus dem historischen Kontextder Studie verbessern Projektionen von Auswirkungen extremer Wetterlagen in derZukunft auf Ernteerträge und Nahrungsmittelproduktion und erleichtern diegesellschaftliche Vorbereitung auf Dürreauswirkungen.

Direct link to Lay Summary Last update: 03.07.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Uncertainty-based auto-calibration for crop yield – the EPIC+ procedure for a case study in Sub-Saharan Africa
Kamali Bahareh, Abbaspour Karim , Lehmann Anthony, Wehrli Bernhard, Yang Hong (2017), Uncertainty-based auto-calibration for crop yield – the EPIC+ procedure for a case study in Sub-Saharan Africa, in European Journal of Agronomy, 93, 57-72.
Adaption to climate change: a case study of two agricultural systems from Kenya
Stefanovic Julia, Yang Hong, Zhou Yuan, Kamali Bahareh, Ogalleh Sarah, Adaption to climate change: a case study of two agricultural systems from Kenya, in Climate and Development.
Spatial assessment of maize physical drought vulnerability in Sub-Saharan Africa: Linking drought exposure with crop failure
Kamali Bahareh, Abbaspour Karim, Lehmann Anthony, Wehrli Bernhard, Yang Hong, Spatial assessment of maize physical drought vulnerability in Sub-Saharan Africa: Linking drought exposure with crop failure, in Global and Planetary Change.

Collaboration

Group / person Country
Types of collaboration
Institute of Atmosphäre und Klima/ETHZ Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Syngenta Fundation, Switzerland Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
Environmental Hydrology, University of KwaZulu-Natal South Africa (Africa)
- in-depth/constructive exchanges on approaches, methods or results
Center for Development Research (ZEF), University of Bonn Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Postdam Institute for Climate Change Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
International SWAT Conference & Workshops Talk given at a conference Climate change impacts on meteorological, hydrological, and agricultural droughts in semi-arid regions of Iran 19.06.2017 Warsaw, Poland Abbaspour Karim; Yang Hong; Kamali Bahareh;
EGU General Assembly 2016 Talk given at a conference Assessment of bio-physical drought hazards. A case study of Karkheh River basin in Ira 11.04.2016 Vienna, Austria Kamali Bahareh; Abbaspour Karim; Yang Hong;
Annual Assembly of Association of American Geographers Talk given at a conference Drought vulnerability assessment of wheat and barley production under climate change-A case study of Karkheh River Basin in Iran 04.04.2016 San Francisco, United States of America Kamali Bahareh; Abbaspour Karim; Yang Hong;


Associated projects

Number Title Start Funding scheme
122479 Global agricultural green and blue water consumptive uses and virtual water flows in the context of water scarcity and climate change 01.02.2009 Interdisciplinary projects
138608 Spatially explicit modeling of impacts of adaptive agronomic measures on crop water productivity and yields in the context of water scarcity and climate change in Sub-Saharan Africa 01.02.2012 Interdisciplinary projects

Abstract

Droughts can have devastating effects on water supply, crop production, food security and many other aspects of human livelihood. The impact is particularly severe in Sub-Saharan Africa (SSA) where rainfed subsistence farming dominates the food production and where political, social and economic systems are often inadequately prepared to cope with disasters. The recurrence of droughts in the past decades has triggered many famines in the sub-continent. The severity of droughts and their impacts is projected to increase as a consequence of climate change. There is a large literature on assessing impact of droughts on food production and vulnerability of a society to droughts. Studies investigating drought impact on crop production in a historical context have typically been conducted by establishing a drought index and correlating it with recorded crop yield or food production in the observed areas. Regression models have been commonly applied for the investigation, where drought effects are presented as a percentage of yields or production variance that could be explained by the model used. Application of process-based bio-physical crop models (crop models hereafter) to specifically quantify the drought effects on crop yield has been very limited in retrospective studies. Large geographical scale crop modeling in assessing drought impact in SSA has, to the best of our knowledge, not been applied. Two shortcomings exist in the drought index-based crop impact assessment. One concern is that the approach cannot specify the types of droughts and most critical times of their impacts on crop yields. In reality, the timing of the occurrence of drought with respect to developmental stages of individual crops is crucial to determining the yield. Another shortcoming is that most such assessments do not distinguish the ‘loss of crop yield’ and ‘failure of production’. In reality, the scopes of the two can be very different. Generally speaking, drought-induced yield loss is more directly related to water stress during crop growth, whereas production reduction in a drought event has multiple drivers, apart from yield loss. This is particularly so in many SSA countries where a relatively small drought often leads to a large reduction in crop production. Concerning the future climate change, it can be expected that the magnitude of the drought impact on crop production will far exceed what is projected based on crop yield loss alone. This gap would especially be large in the regions that are more vulnerable to drought. Motivation of the proposed project is to address the above specified gaps in the assessment of drought impact on crops. Here we propose to apply a process-based biophysical crop model to quantify the impact of droughts on crop yields and food production in a historical context. The study offers the opportunity to perform a large geographical scale crop modeling with high spatial resolution over the whole of SSA. Three specific objectives of the proposed project include: 1) Applying the GIS based crop model (GEPIC) to simulate the impact of historic droughts on crop yields with specification of duration and types of droughts concerning different stages of crop growth; 2) Assessing the crop-drought vulnerability by incorporating the yield loss (simulated), the relative production failure (statistics), as well as the frequency of drought events (identified); 3) Investigating the socio-economic factors influencing the crop-drought vulnerability and mapping out the hot spots of high vulnerability to droughts in SSA. The proposed project endeavors to advance the applicability of crop models for assessing drought impacts on crop yields and crop-drought vulnerability, while pinpointing the limitations that remain. By providing an integrated bio-physical and socio-economic assessment, the study helps identify entry points for developing effective measures to improve the drought coping capacity in SSA. Last but not least, the knowledge learnt from the historical context helps enhance the projection of impact of future extreme dry weather conditions on crop yield and food production and facilitate the societal preparedness to drought impact.
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