Mapping spatio-temporal changes of Chinese electric power consumption using night-time imagery

China's rapid economic development in the last 20 years has resulted in increased demand for electricity and ensuing shortages in electric power supply. It is necessary to derive accurate and timely information regarding changing spatio-temporal patterns and trends of electric power consumption to inform future electricity allocation. Night-time annual image composites for 1995-2005 were obtained from the Defense Meteorological Satellite Program's Operational Linescan System and were inter-calibrated. The inter-calibrated night-time image composites were used in conjunction with the LandScan 2008 population data to estimate the amounts of electric power consumption in 1995, 2000 and 2005 for China at the province level. The estimated amounts of electric power consumption were then disaggregated to the pixel level. A pixel-based map was produced to show the spatio-temporal changes of electric power consumption from 1995 to 2005, in which 11 regional agglomerations with large increases of electric power consumption had emerged. During the process of producing this spatio-temporal change map, some errors were generated because of the use of single-year LandScan population data, imperfect reference regions for inter-calibration and a single threshold value for delimiting urban areas. However, we believe these errors are limited and acceptable, so we present this method of estimation and disaggregation to show the increases in electric consumption.