Better data for geographic targeting of resources: the role of earth observation data for mapping social and economic conditions.

Planning for disaster responses and targeting interventions to mitigate future problems requires frequent, up-to-date data on social, economic and ecosystem conditions. Monitoring socioeconomic conditions using household survey data requires national census enumeration combined with annual sample surveys on consumption and socioeconomic trends, the cost of which is prohibitive. We examine the role that Earth Observation (EO) data could have in mapping poverty in rural areas by exploring two questions; (i) can household wealth be predicted from RS data? (ii) What role can EO data play in future geographic targeting of resources? Here, we demonstrate that satellite data can predict the poorest households in a landscape in Kenya with 62% accuracy. When using a multi-level approach, a 10% increase in accuracy was achieved compared to previously used single-level methods which do not consider how landscapes are utilised in as much detail. EO derived data on buildings within a family compound (homestead), amount of bare agricultural land surrounding a homestead, amount of bare ground inside the homestead and the length of growing season were important predictor variables. A multi-level approach to link RS and household data allows more accurate mapping of homestead characteristics, local land uses and agricultural productivity. High-resolution EO data could provide a limited but significant contribution to geographic targeting of resources, especially when sudden changes occur that require targeted responses. The increasing availability of high-resolution satellite data and volunteered geographic data means this method can be modified and upscaled to larger scales in the future.