Co-designing effective Nature-based Solutions in coastal West Africa

随着气候变化抬高海平面并导致风暴更频繁地发生，居住在沿海地区的社区面临着越来越大的沿海洪水风险。红树林可以帮助保护社区免受这种威胁，因为它们减少了海浪和风暴潮的能量，并阻止沉积物，帮助海岸跟上海平面上升的步伐。尽管它们受益，但自1980年以来，西非三分之一的红树林已经消失。红树林是居住在附近社区的重要燃料和建筑材料来源，但也存在将红树林种植的土地用于盐分生产和水稻种植的压力。已经尝试了许多措施来保护红树林，但这些干预措施可能会对人类和环境产生深远的影响，并创造出新的红树林景观，可能无法像天然红树林那样保护社区。这个项目将产生关于不同干预措施的反馈以及不同红树林景观在保护社区方面的有效性的新知识，并利用这些知识支持几内亚、利比里亚和塞拉利昂的社区设计保护和恢复红树林的解决方案，并保护自己免受气候变化风险的影响。我们将基于社区对红树林、红树林变化及其与人的关系的知识，并与社区合作，想象与红树林生活的不同方式。然后，我们将收集评估这些不同情景所需的证据。这包括对不同的红树林景观如何保护社区免受洪灾的影响进行测量和建模，观察这种保护对红树林上游河流的采矿或森林丧失等过程的敏感性，以及看看不同的红树林保护战略是否对某些人的影响比其他人更大。我们将与社区一起检查这些结果，改进场景和模型，以得出共同设计的解决方案。然后，我们将与社区合作，确定他们是否有能力实施这些解决方案，并确定政府和其他组织如何帮助支持社区保护和恢复红树林。我们将评估不同方法保护和恢复红树林的适宜性是否取决于环境或社会因素。例如，一些河流携带大量泥沙，可以被小面积的红树林捕获，而另一些河流的泥沙较少，可能不会被小片红树林有效地捕获。同样，人们从砍伐红树林转向从其他来源获得木材的选择将取决于其他森林的距离有多近，可用于种植新树的土地数量，以及从更远的地方带来木材的便利性。我们将在西非三个国家的六个不同的河流流域开展工作，这些流域在许多环境和社会特征上存在差异，包括它们离城市地区有多近，那里的产品很容易买卖，河流沿线的森林损失量以及过去国内冲突的经历。我们将与每个流域内三个地区的社区合作，使我们能够看到生计和习俗差异对可能的解决方案的影响。这些关于环境重要性的经验教训将对整个区域保护和恢复红树林的努力起到指导作用。

Communities living near coasts are increasingly at risk from coastal flooding as climate change raises sea-levels and causes storms to occur more frequently. Mangrove forests can help protect communities from this threat, as they reduce the energy of waves and storm surges, and trap sediment to help coasts keep pace with rising sea levels. Despite their benefit, a third of mangroves in West Africa have been lost since 1980. Mangrove wood is an important source of fuel and construction material for communities living nearby, and there are also pressures to use the land mangroves grow on for salt production and rice farming. Many interventions have been tried to protect mangroves, but these can have far-reaching consequences for people and the environment, and create novel mangrove landscapes which may not protect communities in the same way as natural mangroves. This project will generate new knowledge about the feedbacks from different interventions and the effectiveness of different mangrove landscapes at protecting communities, and use this to support communities in Guinea, Liberia and Sierra Leone to design solutions to protect and restore mangroves, and protect themselves from climate change risks.We will build on the knowledge communities have of mangroves, their changes and their relationship with people, and work with communities to imagine different ways of living with mangroves. We will then collect the evidence needed to evaluate these different scenarios. This includes making measurements and models of how different mangrove landscapes protect communities from flooding, looking at how sensitive this protection is to processes such as mining or forest loss along the rivers upstream of the mangroves, and seeing whether different strategies to protect mangroves affect some people more than others. We will examine these results with communities, refining scenarios and models to arrive at co-designed solutions. We will then work with communities to identify whether they have the power to implement these solutions, and identify how governments and other organisations can help support communities to protect and restore mangroves.We will assess whether the suitability of different approaches for protecting and restoring mangroves depends on the environment or on social factors. For example, some rivers carry a lot of sediment which could be trapped by small areas of mangroves, while other rivers have less sediment which may not be effectively trapped by small patches of mangroves. Likewise, options for people to switch from cutting mangroves to getting wood from alternative sources will depend on how close other forests are, the amount of land available for planting new trees, and the ease of bringing wood in from further afield. We will work in six different river catchments in three countries in West Africa, which differ in many environmental and social characteristics including how close they are to urban areas where products can be easily bought or sold, the amount of forest loss along the rivers and experience of past civil conflicts. We will work with communities in three areas within each catchment, allowing us to see the effect of differences in livelihoods and customs on possible solutions. These lessons learnt about the importance of context will be valuable for informing efforts to protect and restore mangroves across the region.