バングラデシュ北部の雹災害に対するリスク評価、適応戦略、リスク管理の枠組み

京都大学新制・課程博士博士(地球環境学)甲第23556号地環博第213号新制||地環||41(附属図書館)京都大学大学院地球環境学舎地球環境学専攻(主査)教授 星野 敏, 准教授 鬼塚 健一郎, 教授 西前 出学位規則第4条第1項該当Doctor of Global Environmental StudiesKyoto UniversityDFA

Rapid Emergence and Increasing Risks of Hailstorms: A Potential Threat to Sustainable Agriculture in Northern Bangladesh

This study investigates the recent changes in natural hazard prioritizations in northern Bangladesh and presents community-based risk analyses of the various natural hazards that present threats to sustainable agriculture. The study area in northern Bangladesh included two union council areas under the Panchagarh sub-district. Climatological data analysis, a detailed questionnaire survey, and focus group discussions were conducted to assess farmers’ perceptions regarding the shifting and identification of hazards, their seasonal variation, and hazard prioritizations. The SMUG (seriousness, manageability, urgency, and growth) and FEMA (Federal Emergency Management Agency) models were applied for hazard prioritization. Hailstorms were found to be the most prioritized hazard over droughts and flash floods as perceived by the community. The farmers’ perceptions as evaluated through a questionnaire survey also support the findings of the SMUG and FEMA models. This was the first attempt to analyze the potential of hailstorms as a significant hazard in Bangladesh, and GIS maps showed their spatial distribution and temporal frequency across Bangladesh. This newly identified hazard is significantly diminishing farmers’ motivation to continue farming and has the potential to affect sustainable agriculture. The farmers’ perceptions, historical data analysis, use of the two models, institutional approach, hazard risk assessment, and vulnerability to the major sectors show that hailstorms should be considered as an important hazard in northern Bangladesh, and policymakers should pay urgent attention to minimize the threat to sustainable agriculture in northern Bangladesh

Assessment of flood vulnerability of riverine island community using a composite flood vulnerability index

The devastating impact of flooding is gradually increasing worldwide including riverine islands of Bangladesh due to climate change issue. Riverine islands and coastal communities are the primary victims due to their geographical position. The riverine islands (char) of Bangladesh are frequently flooded, necessitating context-specific flood management policies and actions that require an in-depth investigation of household vulnerability level. Therefore, this study assesses the vulnerability level of riverine island dwellers to flooding. Data were collected from 384 household heads living in geographically isolated char areas. A context-specific composite flood vulnerability index was developed under the IPCC framework. The results reveal that all households are vulnerable to flooding and are poorly able to cope with its adverse effect. Households living near the mainland have a somewhat more adaptive capacity than distant households. Flood vulnerability is mainly determined by char households' flood perception, damage, and access to food, water and health resources during flooding. Riverbank erosion, recurrent floods, a lack of employment, and limited access to essential public services were also identified as the primary socio-economic and natural causes of flood vulnerability. To decrease the livelihood risk and promote char dwellers’ resilience, a char-based policy plan with both a short- and a long-term focus is required