Assessing health, livelihoods, ecosystem services and poverty alleviation in populous deltas

三角洲地区可能是最脆弱的沿海环境类型，其生态系统服务在未来几十年将面临多重压力。这些压力包括，除其他外，由于地面沉降，三角洲内人口增长和城市化造成的当地驱动因素，由于集水区管理变化（例如上游土地利用和大坝建设）造成的区域驱动因素，以及全球气候变化影响，如海平面上升。河流三角洲的生态系统服务支持高人口密度，估计全球人口超过5亿，尤其集中在南亚、东亚和非洲。这些人中有很大一部分处于极端贫困状态，极易受到环境和生态压力及退化的影响。在接近或低于贫困界限的地区，经济的生存要素和现金要素往往不成比例地严重依赖支撑生计的生态系统服务。了解如何可持续地管理三角洲地区的生态系统服务，从而改善健康，减少贫困和脆弱性，需要考虑所有这些压力及其复杂的相互作用。该提案旨在开发方法来理解和描述影响世界人口众多的三角洲地区环境和经济状况的生态系统服务变化的关键驱动因素。这将通过分析生态系统服务不断演变的作用，探索变化对三角洲居民生计的影响，并制定管理和政策选择来实现，这些选择将有利于现在和未来面对未来几十年乃至更长时间的巨大不确定性。孟加拉国境内的恒河-布拉马普特拉河-梅克纳河三角洲广阔的沿海边缘被选为这项工作的试点研究区域。这是因为孟加拉国几乎完全位于世界上最大、最具活力的三角洲之一。它的特点是人口密集的沿海低地和显著的贫困，在很大程度上由自然生态系统支持，如桑德班斯（世界上最大的红树林）。由于许多不断发展的城市，如库尔纳和首都达卡，它面临着严重的发展压力。目前，人们对生态系统服务对贫困和生计的重要性知之甚少。这是由于物理驱动因素、环境压力和人类对压力的反应以及由此产生的对生态系统的影响之间相互作用的复杂性。政府的政策很少考虑生态系统服务的观点，因此对其价值的全面概述往往被忽视。本项目旨在通过向政策制定者提供知识和工具，使他们能够评估政策决定对人民生计的影响，从而弥补这一差距。要做到这一点，就要建立一种全面的方法，在诸如三角洲地区的下沉和海平面上升、土地退化和人口压力等变化的背景下，正式评估生态系统服务和贫困。这将在孟加拉国沿海地区进行试验和应用，并在其他人口稠密的三角洲进行概念试验。

Delta regions are probably the most vulnerable type of coastal environment and their ecosystem services face multiple stresses in the coming decades. These stresses include, amongst others, local drivers due to land subsidence, population growth and urbanisation within the deltas, regional drivers due to changes in catchment management (e.g. upstream land use and dam construction), and global climate change impacts such as sea-level rise.The ecosystem services of river deltas support high population densities, estimated at over 500 million people globally, with particular concentrations in Southern and Eastern Asia and Africa. A large proportion of these people experience extremes of poverty and are severely exposed to vulnerability from environmental and ecological stress and degradation. In areas close to or below the poverty boundary, both subsistence and cash elements of the economy tend to rely disproportionately heavily on ecosystem services which underpin livelihoods.Understanding how to sustainably manage the ecosystem services in delta regions and thus improve health and reduce poverty and vulnerability requires consideration of all these stresses and their complex interaction. This proposal aims to develop methods to understand and characterise the key drivers of change in ecosystem services that affect the environment and economic status in the world's populous deltas. This will be done through analysis of the evolving role of ecosystem services, exploring the implications of changes for the livelihoods of delta residents, and developing management and policy options that will be beneficial now and in the future in the face of the large uncertainties of the next few decades and beyond.The extensive coastal fringe of the Ganges-Brahmaputra-Meghna Delta within Bangladesh has been selected as the pilot study area for this work. This is because Bangladesh is almost entirely located on one of the world's largest and most dynamic deltas. It is characterised by densely populated coastal lowlands with significant poverty, supported to a large extent by natural ecosystems such as the Sunderbahns (the largest mangrove forest in the world). It is under severe development pressure due to many growing cities, eg Khulna and the capital, Dhaka.At present the importance of ecosystems services to poverty and livelihoods is poorly understood. This is due to due to the complexity of interactions between physical drivers, environmental pressures and the human responses to stresses and the resultant impacts on ecosystems. Government policy rarely takes up the ecosystems services perspective and as a result an holistic overview of their value is often overlooked.This project aims to address this gap by providing policy makers with the knowledge and tools to enable them to evaluate the effects of policy decisions on people's livelihoods. This will be done by creating a holistic approach to formally evaluating ecosystems services and poverty in the context of changes such as subsidence and sea level rise, land degradation and population pressure in delta regions. This will be tested and applied in coastal Bangladesh and tested conceptually in other populous deltas.