U-Alert

关键词：非洲，洪水，热浪，空气污染，气候变化适应，移动数据，卫星，遥感，城市，风险摘要：非洲是世界上对气候变化最脆弱的大陆之一，适应能力和恢复力普遍较低。气候变化已经加剧了许多发展挑战，如地方性贫困和不平等、生态系统退化、与自然灾害有关的灾害和粮食安全。近年来，包括干旱和强降雨事件在内的极端气候事件的频率和严重程度有所增加。这些气候事件正在对人们的生活和生计产生重大影响，造成热浪、洪水和空气污染造成的死亡和破坏。气候变化也使这些事件更加难以预测和管理，特别是在人口稠密的城市环境中，应急服务和基础设施往往不足，因此无法应对迅速变化的局势和同时发生的多重压力。与此同时，由于人们为了寻求更好的就业机会和生活水平而从农村地区移徙，城市地区的人口越来越多。由于人口的突然涌入（以及城市地区和贫民窟的扩大），许多弱势群体被迫在洪泛平原和陡坡等边缘土地上定居，因此面临更大的风险。为了更好地预测和应对极端气候事件，对新形式的环境监测的需求日益增长。不幸的是，非洲许多地区的特点是环境数据差，气象站稀少，缺乏观测来验证和缩小气候变化预测，准确预测和评估影响，以及为短期/长期适应战略提供信息。非洲的许多城市和基础设施用户依赖受数据限制的国际和国家专家的服务和专门知识，这些专家依赖于粗糙分辨率的气候数据和预测，这可能导致误解和发布错误信息。因此，迫切需要建立更好的局部灾害预测系统，以监测和管理洪水、热应激和空气污染等极端事件的影响，并直接向面临风险的人群提供信息。研究表明，在没有现场数据的情况下，移动电话天线之间发送的信号可以提供一种测量降雨强度和持续时间的替代方法。这些数据可以与灾害模型相结合，以预测城市地区洪水的程度和范围。此外，其他研究表明，可以通过智能手机内部传感器和测量电池放电波动获得准确的气温信息。同时，卫星衍生的气溶胶测量可以提供有关空气污染和公共健康风险的信息。上述移动衍生数据与遥感技术相结合，可用于向城市人口发出即将到来的气候风险警告。在发展中国家，移动电话的数量和使用不断增加，使得短信警告和建议能够传递给那些需要这些信息的人，同时也成为通过创建“公民观测站”收集重要气候变量数据的一种手段。该项目旨在评估将这些技术结合起来收集城市风险和脆弱性信息的可行性和范围，对其进行分析以产生警告，并以“易于操作”的信息直接发送给受影响地区的移动电话用户。

Key words: Africa, floods, heat waves, air pollution, climate change adaptation, mobile data, satellite, remote sensing, urban, riskSummary:Africa is one of the most vulnerable continents in the world to climate change with widespread low adaptive capacity and resilience. Climate change is already exacerbating many development challenges such as endemic poverty and inequality, ecosystem degradation, natural hazard related disasters and food security. The frequency and severity of extreme climatic events including droughts and intense rainfall events has increased in recent years. These climatic events are now having a significant impact on people's lives and livelihoods causing deaths and damage from heat waves, flooding and air pollution. Climate change is also making these events more unpredictable and difficult to manage, especially in densely populated urban environments where emergency services and infrastructure is often inadequate and thus unable to respond to rapidly changing situations and multiple simultaneous pressures.At the same time, urban areas are becoming increasingly populated as people migrate from rural areas in search of better employment opportunities and a standard of living. Due to this sudden influx of people (and expansion of urban areas and slums), many vulnerable people are being forced on settle on marginal land such as flood plains and steep slopes and thus being placed at greater risk. There is a growing demand for new forms of environmental monitoring to better predict and be able to respond extreme climatic events. Unfortunately, many regions in Africa are characterised by poor environmental data and sparse weather stations, there is a lack of observations to validate and downscale climate change projections, accurately predict and assess impacts as well inform short/long term adaptation strategies. Many cities and infrastructure users in Africa are reliant on the services and expertise of international and national experts constrained by data limitations, who are reliant on coarse resolution climate data and projections which can result in misinterpretation and misinformation being issued. There is thus a pressing need for better localised hazard prediction systems to monitor and manage the impacts of extreme events such as flooding, heat stress and air pollution, informed from and delivered directly to at risk populations.It has been demonstrated that signals sent between mobile phone antennas can provide an alternative means to measure rainfall intensity and duration in situations where in-situ data isn't available. This data can be combined with hazard models to predict the degree and extent of flooding in urban areas. Furthermore, other studies have demonstrated that accurate air temperature information can be derived from internal smartphone sensors and by measuring battery discharge fluctuations. Simultaneously, satellite derived aerosol measurements can provide information on air pollution and public health risks. The combination of the aforementioned mobile derived data and remote sensing techniques can be used to warn urban populations of impending climate risks. The growing number and use of mobile phones in developing countries allows SMS warnings and advice to be delivered to those in need of this information, as well as a means to collect data on essential climate variables through the creation "citizen observatories". This project aims to assess the feasibility and scope of bringing together such technologies to collect information of urban risk and vulnerability, analyse it to produce warnings and deliver it directly to mobile phone users in affected areas in an "easy-to-action" message.