The impact on human health of restoring degraded African drylands

这一多国项目旨在确定非洲萨赫勒地区大规模土地恢复的健康效益。我们将利用非洲绿色长城倡议，这是世界上最大的土地恢复努力，作为一个自然实验系统。旱地居住着全球近40%的人口。GGW和目前世界各地正在进行的其他类似土地恢复工作将重塑全球数十亿人的景观和生活体验。随着世界寻求应对和适应气候变化、生物多样性丧失和粮食安全这三重挑战，这种恢复努力越来越被视为潜在的“基于自然的解决方案”。然而，目前，人类健康因素在包括GGW在内的恢复项目的设计和实施中发挥着非常小的作用。该项目旨在填补这一关键空白，确保恢复项目能够最大限度地为人类健康服务。我们将使用一个新的活动组合，跨越4个集成的工作包来做到这一点。简而言之，第一工作方案将包括文献审查和社区协商，以制定一个反复完善的、对性别问题敏感的逻辑模型，描述旱地恢复与人类健康之间的因果关系。这将通过帮助完善关键假设并确定在随后的WP中评估的次级健康结果的适当子集来指导项目。在第二工作方案中，我们将尽可能多地整理现有数据，供全球水资源状况国家进行萨赫勒地区村庄匹配的健康影响评估。研究的主要结果将是儿童（0-59个月）的年龄别体重z评分（WAZ），作为急性营养状况的衡量标准。还将考虑WP 1中出现的儿童和妇女的次要结果的子集，因为它们特别相关。我们将比较有和没有GGW活动的社区之间的健康结果，以评估恢复的健康影响。WP 3将是WP 1 -2的后续行动，我们将在三个重点国家（冈比亚、塞内加尔、布基纳法索）进行更有针对性、社区优先、与村庄匹配的健康影响评估，并收集原始数据。根据我们目前对健康与环境恢复之间联系的理解，这些措施可能包括其他人体测量措施（例如，年龄别身高z评分（HAZ），以及反映营养、感染和心理健康/福祉途径风险因素的结局。我们将再次关注儿童和非孕妇。一些次要结果需要从儿童中收集生物样本进行实验室分析。后续采样将提供有关季节性影响的信息，并有机会在12-14个月期间比较有和没有GGW干预的组之间的儿童生长情况。WP 4包括一系列综合任务，旨在将健康影响评价的结果与当前指导设计和实施全球治理工作的活动结合起来，并了解完成全球治理工作对健康的作用和益处。预计到2030年实现1亿公顷旱地恢复目标的费用约为500亿美元，因此必须将健康影响（效益和成本）纳入现有的决策支持工具，以供应用。我们将通过卫生经济评估、成本效益和权衡分析以及气候变化背景下的系统和情景建模等步骤来实现这一目标。在所有WP中，我们的项目合作伙伴和科学指导委员会将进一步确保本地相关性，并简化研究到实践的管道，提高影响力。

This multi-country project aims to establish the health benefits of large-scale land restoration in Africa's Sahel region. We will leverage the Great Green Wall (GGW) of Africa initiative, the largest land restoration effort in the world, as a natural experimental system. Drylands host nearly 40% of the global population. The GGW and other similar land-restoration efforts currently underway around the world are set to reshape landscapes and the lived experiences of billions of people globally. Such restoration efforts are increasingly being regarded as potential 'Nature-based solutions' as the world seeks to confront and adapt to the triple challenges of climate change, biodiversity loss and food security.At present however, human health considerations play a very minor role in the design and implementation of restoration projects, including the GGW. This project aims to fill this critical gap, to ensure restoration projects can maximally serve human health alongside other objectives. We will use a novel combination of activities spanning 4 integrated work packages to do this. Briefly, WP1 will comprise a literature review and community consultations to develop an iteratively refined, gender-sensitive logic model describing the causal linkages between dryland restoration and human health. This will guide the project by helping to refine key hypotheses and identify a suitable subset of secondary health outcomes to be evaluated in subsequent WPs. In WP2 we will collate as much existing data as possible for GGW countries to conduct a Sahel-wide village-matched health impact evaluation. The primary outcome to be investigated will be weight-for-age z score (WAZ) of children (0-59 months) as a measure of acute nutritional status. A subset of secondary outcomes in children and women emerging from WP1 as of particular relevance will also be considered. We will compare health outcomes between communities with and without GGW activities to evaluate the health impacts of restoration. WP3 will be a follow-up of WPs1-2 in which we will conduct a more targeted, community-prioritised, village-matched health impact evaluation with primary data collection in three focal countries (The Gambia, Senegal, Burkina Faso). Based on our current understanding of the linkages between health and environmental restoration, these are likely to include other anthropometric measures (e.g., height-for-age z score, HAZ), and outcomes reflecting risk factors on the nutrition, infection and mental health / well-being pathways. We will again focus on children and non-pregnant women. Some secondary outcomes require collection of biological samples from children for laboratory analysis. Follow-up sampling will give information on seasonal effects and an opportunity to compare child growth over a 12-14 month period between groups with and without GGW interventions. WP4 comprises a set of integrating tasks aimed at marrying the results of the health impact evaluations with current activities guiding the design and implementation of the GGW and understanding the role of and benefits to health of completing the GGW. With an anticipated cost of around $50 billion to reach its 100 million hectare target of restored drylands by 2030, it is essential for health impacts (benefits and costs) to be brought into existing decision-support tools for applied purposes. We will do this via a combination of steps from health economic evaluation, cost-benefit and trade-off analysis, and systems and scenario modelling in the context of a changing climate. In all WPs, our Project Partners and Scientific Steering Committee will further ensure local relevance and streamline the research-to-practice pipeline, enhancing impact.