ABSTRACT
Urbanization is a leading trend in the Asia-Pacific where major cities are threatened by natural hazards such as urban flooding. However, annual urban maps were not available because of the limited field observation and regular mapping plans. This study aimed to map impervious surfaces, an indicator for urbanization, in the greater Hanoi area, Vietnam, by time series analysis of normalized difference vegetation index and land surface temperature. Then, time series similarity measure, decision tree classifier, and temporal filtering were applied to generate annual impervious surface maps representing the urbanization process in the study area. Urbanization in the study area showed a 305% increase in the area of impervious surface from 1988 to 2015. This trend was consistent with the two phases of economic development in Vietnam including the 1986 to 2000 and the 2000 to 2015 periods characterized by the transition to market-based economy and explosive development of economic corporations, respectively.
