Acta Geographica Sinica ›› 2015, Vol. 70 ›› Issue (8): 1339-1350.doi: 10.11821/dlxb201508012

• Orginal Article • Previous Articles     Next Articles

An EVI-based method to reduce saturation of DMSP/OLS nighttime light data

Li ZHUO1(), Xiaofan ZHANG1, Jing ZHENG2, Haiyan TAO1(), Yubo GUO1   

  1. 1. Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation / Center of Integrated Geographic Information Analysis, School of Geography and Planning, Sun Yat-sen University, Guangzhou 510275, China
    2. Guangdong Climate Center, Guangzhou 510080, China
  • Received:2014-10-27 Revised:2015-01-31 Online:2015-08-20 Published:2015-08-20
  • Supported by:
    National Natural Science Foundation of China, No.41371499;The startup fund for Prof.Liu Lin from the One Thousand Talents Program of Sun Yat-sen University

Abstract:

DMSP/OLS nighttime light (NTL) data has been widely applied to many studies on anthropogenic activities and their effects on the environment. Due to the limitations of the OLS sensor, NTL data suffers from saturation problem in the core of urban areas, which further influences researches based on nocturnal lights. The radiance calibrated nighttime light (RCNTL) products developed by the National Geophysical Data Center (NGDC) at NOAA partially solved the problem. However, they are only available for a very limited number of years. Recently, a vegetation adjusted NTL urban index (VANUI) has been developed based on the stylized fact that vegetation and urban surfaces are inversely correlated. Despite its simplicity of implementing and effectiveness in increasing variation to NTL data, VANUI does not perform well in some fast growing cities. In this paper, we proposed a new urban index, i.e., the Enhanced Vegetation Index (EVI) adjusted nighttime light index (EANTLI), which combined MODIS EVI with NTL to alleviate the saturation problem of NTL data. In order to evaluate the proposed EANTLI's capability in reducing NTL saturation, we first compared its spatial distributions in potential saturated areas (PSAs) of three metropolitan areas in China with that of the original NTL and VANUI, respectively. Then we randomly selected 30 latitudinal transects across these urban areas to verify EANTLI's similarity to the RCNTL. Finally, we tested EANTLI's effectiveness in assessing electric power consumption of 168 prefecture-level cities in China. Results from these experiments showed that EANTLI significantly increases spatial heterogeneity in the PSAs and effectively alleviates the NTL saturation problem. EANTLI's similarity to RCNTL is consistently higher than that of VANUI in the comparison of latitudinal transects. EANTLI also yields better results in the estimation of electric power consumption. In conclusion, the EANTLI can effectively reduce NTL saturation in urban centers and thus has great potential of wide range applications in the future.

Key words: DMSP/OLS, nighttime light, EANTLI, saturation, EVI