Spatial Analysis of The World Bank's Global Urban Air Pollution Dataset

This paper describes the method used to spatially render the World Bank's air pollution database of modelled PM10 concentrations for some 3,200 locations across the world for cities over 100,000 people and capital cities. The dataset has very good spatial coverage with each of the 11 GGI regions well populated by data points. Mapping these point concentrations with respect to population density reveals that most densely populated areas of the world are well accounted for with the exception of sub-Saharan Africa. In total, 1.96 billion people are accounted for, which is 2/3 of the total global urban population. South Asia and the Middle East/North Africa have the highest average concentration. Concentrations and exposures are then mapped according to World Health Organization guidelines. It is found that much of the urban populations in the world's most populous countries have concentrations that lie outside of even the lowest air quality targets. Finally, concentrations are compared to other spatially explicit datasets of pollutants to build a picture of spatial air pollution patterns and help to understand the characteristics of the model

CIESIN Thematic Guide to Night-time Light Remote Sensing and its Applications

Night-time light imagery stands unique amongst remote sensing data sources as it offers a uniquely 'human' view of the Earth's surface. The presence of lighting across the globe is almost entirely due to some form of human activity be it settlements, shipping fleets, gas flaring or fires associated with swidden agriculture. This extensively illustrated guide introduces users to the types of night-time light data available, its characteristics and limitations. It details the distinguishing features of the stable lights, radiance calibrated and time series Average DN datasets. The latter currently spans the period 1992-2003. The spatial and temporal characteristics of the datasets are presented using a range of techniques including temporal color composites. Preliminary analysis of this time series reveals considerable differences in brightness between data collected from different platforms. The second part of the guide examines how this interesting data source has been used and may be used to derive useful information about human presence and practice on Earth. Topics range from population and light pollution to economic activity, greenhouse gas emissions and using night-time lights to help with disaster management. Consideration is also given to the ecological ramifications of night-time lighting. With these elements set out, the final section explores other potential sources of night-time light data and how future systems may enhance our existing capabilities to understand the human environment through this the observation of lights at night

Estimating rural populations without access to electricity in developing countries through night-time light satellite imagery

A lack of access to energy and, in particular, electricity is a less obvious manifestation of poverty but arguably one of the most important. This paper investigates the extent to which electricity access can be investigated using night-time light satellite data and spatially explcit population datasets to compare electricity access between 1990 and 2000. We present here the first satellite derived estimates of rural population without access to electriciy in developing countries to draw insights on issues surrounding the delivery of electricity to populations in rural areas. The paper provides additional evidence of the slow progres in expansion of energy access to households in Sub-Saharan Africa and shows how this might be ascribed in part due to the low population densities in rural areas. The fact that this is a continent with some of the lowest per-capita income levels aggravates the intrinsic difficulties associated with making the investments needed to supply electricity in areas with low population density and high dispersion. Clearly, these spatial dimensions of the distributions of the remaining unelectrified populations in the world have an impact on what options are considered the most appropriate in expanding access to these households and the relative attractiveness of decentralized options