A study of water hazard-related loss and damage in the Ganges- Brahmaputra-Meghna River basin

Abstract

This study on climate change Loss and Damage (L&D) covers the three significant knowledge gaps in the 'L&D Work Programme' of the United Nations Framework Convention on Climate Change (UNFCCC). These are i) providing a universal definition of damage, ii) codifying a robust assessment methodology, and iii) and offering perspectives on how L&D analysis can be practically implemented. Water resources are situated at the centre of this thesis because the analysis contained herein illustrates that two-thirds of all-natural disasters worldwide are water-related.

The concept of L&D is the latest addition to the UNFCCC's work programme. However, multiple meetings of the Conference of the Parties (COP) have highlighted the need for deeper understanding and common terms of reference. Using the Systematic Review technique revealed how L&D is different from climate impact and why the conventional mitigation and adaptation approaches are not adequate. It illustrates how empirical evidence is needed to augment theory. A candidate universal definition was developed drawing on place-based analysis in one of the world's great river basins, the Ganges-Brahmaputra-Meghna (GBM) mega-basin, with a particular focus on Bangladesh.

The narrative of this thesis begins with the global drivers of change (e.g. emission scenarios), cascading through regional climatic indices (e.g. temperature and precipitation anomalies) down to the local level impacts – where L&D is experienced. Parametric trend analysis reveals that the intensity and frequency of all water-related hazards, i.e. hydrological, climatological, and metrological hazards, are significantly increasing. A modified normalised economic analysis of these water-related disasters was undertaken revealing financial costs of c. US$1.7 trillion over the last three decades, effectively US$30 billion a year and rising. Similarly, if the total number of people affected by the disaster and the total number of people killed in the disaster are used as proxy indicators for damage and loss, South Asia emerges as an L&D hotspot in terms of human suffering. This result justifies the selection of the GBM for the regional and local focus in this thesis. In terms of economic losses, North America stands out from all other regions.

Aggravating climatic risks in physically and politically diverse GBM basin are highly contentious issues around equitable and sustainable transboundary water management. This study set up a regional level hydrological model in the GBM basin using the semi-distributed hydrological model SWAT. Water availability indicators, such as ‘Blue Water’ availability , show that by 2100 many new areas will experience water stress and security issues. The modelling showed that monsoonal floods and water scarcity during the dry season will both intensify and extend significantly by the end of this century. Hazard analysis shows that the likelihood of disastrous flooding in the GBM basin will increase by 80 per cent by the 21st century, with flood duration prolonged and its delayed recession aggravating direct risks to people and indirect risks associated with food (crop) insecurity. In addition, drought will increase in several river basins, of which ‘Green Water’ availability will become a significant presenting issue in the lower Brahmaputra basin in Bangladesh. Because the Ganges Basin has the most hydrological regulation through structural interventions, this system is especially vulnerable.

An extensive field campaign was undertaken across five regions in Bangladesh, exploring current and future L&D in terms of people and local places. This sought to capture the experiences of living with environmental change and explore coping and adaptation measures at the community and family level to address them. These case studies cover the prevalence of rapid onset (such as seasonal floods, flash floods and storm surges) and slow-onset event (such as sea level races, salinity intrusions and drought) in the selected areas. Statistically robust sampling and questionnaires survey of 506 households showed all are exposed to climate-related shocks and stressors, of which 91% of households suffer from L&D despite adopting some coping or adaptation strategies. The mean annual economic loss per household is c.US$2,500/yr, which exceeds the mean annual per capita GDP in Bangladesh (US$2,100). It implies that their earnings are not adequate to cover up the disaster L&D, so they rely heavily on various financial assistance such as loans and external aids. A recurrent pattern was the erosion of adaptive capacity erodes over time, meaning families cannot recover between shocks.

Drawing from more than one hundred in-depth interviews, the human face of L&D was elucidated. Rich qualitative insights confirmed that conventional water management infrastructures such as embankments for protection against flood and storm surge are inadequate to ensure safety and security of life and livelihood to families. Further, long-term environmental impacts of structural adaptation options often outweigh their benefits. One of the main reason’s households cannot address L&D is the lack of entitlement to land and essential lifeline services such as clean drinking water, sanitation, access to electricity, food security. Therefore, crafting strategies for a water management solution that addresses the entitlement right of the affected households are critical to addressing L&D.

Because of the persistent and indeed deteriorating geopolitical disputes over transboundary water rights and the slow progress of UNFCCC processes, it is unclear that global initiatives will reach the most marginalised families over short to medium timescales. As a result, the final section of this thesis used an action-based research approach to demonstrate the concept of a ‘flood resilient home'. A prototype flood resilient home, in particular, was designed to address entitlement concerns by incorporating sustainable livelihood, food and nutrition safety, potable water, waste management, and renewable energy features, allowing a family to live their lives uninterrupted both during the disaster and non-disaster periods. In the event of a disaster and the rest of the year, it will provide a family with enhanced protection and give access to other lifeline services, generating goods and services of US $ 2,100 a year. The intersectional analysis highlighted the importance of empowering women to address L&D. The potential of this concept received the prestigious UN Risk Award 2019 and a Commendation in the Times Higher Education Awards 2019, as ‘research project of the year’ in the arts and social sciences category.

Date of Award	2021
Original language	English
Supervisor	John Rowan (Supervisor)