Sarwar Hossain

Sustainable Development Goals Offer New Opportunities for Tropical Delta Regions

Marine and lacustrine delta regions constitute only 1% of the Earths surface but are home to over 500 million people.1 They are key contributors to agricultural production at the national and regional levels and thus enable alleviation of global food insecurity risks. In addition, tropical megadeltas sustain rich ecosystems that provide a variety of services and are noted for high biodiversity and natural resources.2 At the same time, however, their geographical location, coupled with often poor land use and river basin management, implies that deltas, more than other coastal areas, are prone to natural hazards and disasters such as subsidence, flooding, coastal erosion, and cyclones/typhoons. These environmental shocks have been proven to lead to high out migration and threaten human security in already relatively economically poor regions.3 Climate change, in particular sea-level rise, exacerbates the existing vulnerabilities by increasing the risks of rapid-onset disasters, as well as creeping processes such as salinity intrusion.4,5 Many deltas around the world are therefore threatened.6 This exposure to environmental change has important consequences on peoples livelihoods and human development of the delta regions and beyond. In the case of the Amazon delta, the state-level human development index of the Brazilian State of Para, where most of the deltaic area is located, is the third lowest among the 27 Brazilian states, with the education subindex ranking second poorest.7 In this commentary we discuss new opportunities for the way that the proposed Sustainable Development Goals (SDGs) agenda interacts with delta regions and highlight key policy measures needed to address the existing gaps.

Identifying future research directions for biodiversity, ecosystem services and sustainability: perspectives from early-career researchers

ABSTRACT We aimed to identify priority research questions in the field of biodiversity, ecosystem services and sustainability (BESS), based on a workshop held during the NRG BESS Conference for Early Career Researchers on BESS, and to compare these to existing horizon scanning exercises. This work highlights the need for improved data availability through collaboration and knowledge exchange, which, in turn, can support the integrated valuation and sustainable management of ecosystems in response to global change. In addition, clear connectivity among different research themes in this field further emphasizes the need to consider a wider range of topics simultaneously to ensure the sustainable management of ecosystems for human wellbeing. In contrast to other horizon scanning exercises, our focus was more interdisciplinary and more concerned with the limits of sustainability and dynamic relationships between social and ecological systems. The identified questions could provide a framework for researchers, policy makers, funding agencies and the private sector to advance knowledge in biodiversity and ES research and to develop and implement policies to enable sustainable future development.

Evolutionary social and biogeophysical changes in the Amazon, Ganges–Brahmaputra–Meghna and Mekong deltas

Policy-making in social-ecological systems increasingly looks to iterative, evolutionary approaches that can address the inherent complexity of interactions between human wellbeing, provision of goods, and the maintenance of ecosystem services. Here, we show how the analysis of available time-series in tropical delta regions over past decades can provide important insight into the social-ecological system dynamics in deltaic regions. The paper provides an exploratory analysis of the recent changes that have occurred in the major elements of three tropical deltaic social-ecological systems, such as demography, economy, health, climate, food, and water. Time-series data from official statistics, monitoring programmes, and Earth observation data are analysed to explore possible trends, slow and fast variables, and observed drivers of change in the Amazon, Ganges–Brahmaputra–Meghna and Mekong deltas. In the Ganges–Brahmaputra–Meghna delta zone, increasing gross domestic product and per capita income levels since the 1980s mirror rising levels of food and inland fish production. In contrast, non-food ecosystem services, such as water availability, water quality, and land stability appear to be deteriorating. In the Amazon delta, natural and anthropogenic perturbations are continuously degrading key ecosystem services, such as carbon storage in biomass and soils, the regulation of water balance, and the modulation of regional climate patterns. In the Mekong delta, rapid economic development, changing land-use practices, and salinity intrusion are progressively putting more pressure on the delivery of important provisioning services, such as rice and inland aquaculture production, which are key sources of staple food, farm incomes, and export revenue. Observed changes in many key indicators of ecosystem services point to a changing dynamic state and increased probability of systemic threshold transformations in the near future.

Restoring water quality in the polluted Turag-Tongi-Balu river system, Dhaka: Modelling nutrient and total coliform intervention strategies

River water quality in rapidly urbanising Asian cities threatens to damage the resource base on which human health, economic growth and poverty reduction all depend. Dhaka reflects the challenges and opportunities for balancing these dynamic and complex trade-offs which goals can be achieved through effective policy interventions. There is a serious problem of water pollution in central Dhaka, in the Turag-Tongi-Balu River system in Bangladesh with the river system being one of the most polluted in the world at the moment. A baseline survey of water chemistry and total coliforms has been undertaken and shows dissolved oxygen close to zero in the dry season, high organic loading together with extreme levels of Ammonium-N and total coliform in the water. Models have been applied to assess hydrochemical processes in the river and evaluate alternative strategies for policy and the management of the pollution issues. In particular models of flow, Nitrate-N, Ammonium-N and indicator bacteria (total coliforms) are applied to simulate water quality in the river system. Various scenarios are explored to clean up the river system, including flow augmentation and improved effluent treatment. The model results indicate that improved effluent treatment is likely to have a more significant impact on reducing Ammonium-N and total coliforms than flow augmentation, but a combined strategy would greatly reduce the pollution problems in the Turag-Tongi-Balu River System.

Understanding the Social-ecological System of Wetlands

The concept of social-ecological system is receiving increasing recognition from the scientific community as a tool for analysing complex phenomena. The wetlands’ social-ecological systems provide valuable economic, social and environmental benefits to society. However, disturbances in wetland system due to human intervention have already led some of the wetlands’ social-ecological system towards the tipping point. Furthermore, in the context of the projected impacts of environmental and climate change, organisms inhabiting and dependent on wetlands, which are at the centre of the social-ecological system, are likely to require greater resilience and innovative coping strategies. The present chapter introduces the concepts of the social-ecological system using real-world case studies from the coastal Ganges-Brahmaputra Delta in Bangladesh in order to facilitate understanding of social-ecological system as well as interactions between ecological factors and human wellbeing. The chapter also discusses the critical issues of managing social-ecological system in order to support sustainable ecosystem management.

Climate Change Impacts and Adaptations in Wetlands

Despite the substantial contribution of wetland resources to support human wellbeing and the threats of climate change on wetland resources, climate studies have paid less attention to wetlands in South Asia. Hence, this chapter explores the impacts and adaptation to climate change on the wetlands of southwest coastal Bangladesh using the time series (e.g. Mann–Kendall) analysis of climate data and survey data analysis for the adaptations to climate change. We have also reviewed the literature to explore whether the local development projects in wetlands integrates climate change adaptations according to the national adaptation plan. The trends of temperature in pre-monsoon, monsoon and post-monsoon are increasing over the period 1948–2012. Pre-monsoon rainfall trend is decreasing, in contrast to the increasing rainfall trends in monsoon and post-monsoon seasons. In response to the changes in climate, 78% of respondents have adopted multiple adaptation options, and 94% of respondents have adopted expensive boring methods to support agriculture. The production cost has increased threefold in response to the changes in crop varieties to cope with climate change. The bivariate probit regression (BPR) reveals that loan taking is the determinant of climate change adaptation. Though the review of literature suggests that the impacts of climate change will be severe in the future, adaptation planning is yet not integrated into the wetlands’ development plans. Some of the adaptation options (e.g. access to credit and innovating crop varieties with low production cost) may be included in the global development goals to strengthen climate change adaptation at global and regional scales.