Study on the emergy-based thermodynamic geography of the Jing-Jin-Ji region: Combined multivariate statistical data with DMSP-OLS nighttime lights data

Abstract Emergy analysis is one of the ecological thermodynamics methods. With a specific set of indicators, it is proved to be highly informative for sustainability assessment of national/regional economies. However, a large amount of data needed for its calculation are from official statistical data by administrative divisions. The spatialization of emergy in early researches were limited to the administrative boundaries. The emergy inside an administrative boundary renders a single value, which hides plenty of information for more precise regional planning. This study develops a new methodology for mapping the spatial distribution of emergy density of a region. The renewable resource distribution can be mapped based on latest geospatial datasets and GIS technology, instead of solely relying on statistics and yearbooks data. Besides, a new spatialization method of non-renewable emergy based on DMSP-OLS nighttime lights data is proposed. Combined with the radiation calibration data, the problem of light saturation of DMSP-OLS nighttime lights data was solved to improve the emergy spatial detail of city centers. With a case study of Jing-Jin-Ji region, results showed that this method could generate a high-resolution map of emergy use, and depict human disturbance to the environment in a more precise manner. This may provide supportive information for more precise land use planning, strategic layout and policy regulation, and is helpful for regional sustainable development.