However, there exist a lot of inconsistencies in
definitions of urban boundaries [15,16], use of data sources
[17], methods of urban area extraction [18–24] and areas of
interest are limited to part or only a single city [15,25–34].
The problems of definition inconsistency, multiple mapping
methods, data and mapping area differences in time and
space, seriously impede the construction of a standard dataset
on urban expansion that could be used in support of
research activities on climate change modeling, regional and
national land use planning, environmental protection and
public health studies. Therefore, it is necessary to map urban
expansions in large areas with data from the same
source during short time duration for temporal consistency,
and with methods that are accurate.