Fig. 1. Geographical location and administrative division of Anhui Province

Fig. 2. DMSP-OLS nighttime light data in 2013(a) and NPP-VIIRS nighttime light data in December 2013(b) of Anhui Province

Fig. 3. Curve fitting of NPP-VIIRS and DMSP-OLS average nighttime light index

Fig. 4. Spatial distribution of average nighttime light index and urbanization level based on statistical data of Anhui Province in 2013

Fig. 5. Average nighttime light index and urbanization level based on statistical data of some districts and counties of Anhui Province from 2006 to 2015

Fig. 6. Linear regression analysis of average nighttime light index and urbanization level based on statistical data