Restoring urbanization process in China in the 1990s by using non-radiance-calibrated DMSP/OLS nighttime light imagery and statistical data

Since implementing the reform and open policy from 1978, China has been experiencing the fast urbaniza- tion process [1]. Recently, understanding the urban pat- tern characteristics and the change processes to adjust and optimize the urban land use patter…

Restoring urbanization process in China in the 1990s by using non-radiance-calibrated DMSP/OLS nighttime light imagery and statistical data

Since current administrative unit-based urban land area statistical data in China lack enough spatial information, the urbanization process re- search at large scale cannot be effectively supported. Based on the current administrative unit-based urban land area statistical data in China, a new approach to quickly and cheaply derive urban land information from the non-radiance-calibrated Defense Meteoro- logical Satellite Program/ Operational Linescan Sys- tem (DMSP/OLS) nighttime light imagery is pre- sented in this paper. With the new approach, the ur- ban pattern information in China in 1992, 1996 and 1998 was derived with the urbanization processes in China in the 1990s restored by using the non-ra- diance-calibrated DMSP/OLS nighttime imagery. The accuracy assessment based on the statistical data showed that the relative error between the derived total urban land area and the statistical data at na- tional scale was less than 2% in 1992, and less than 1% in 1996 and 1998, and the maximum relative er- ror at province scale do not exceed 10% with most of the provinces less than 3%. In addition, the urban patterns derived from the high-resolution Landsat TM imagery were compared with those from the DMSP/ OLS data. The results showed that the urban pattern characteristics derived from DMSP/OLS were basi-cally coincident with those from TM imagery with the total accuracy of about 80%. Thus it can be seen that our restored urbanization process in China in the 1990s by using the non-radiance DMSP/OLS night- time imagery can be accepted and can represent the actual urban development in China at that time on the whole.