Impervious Surface Expansion: A Key Indicator for Environment and Urban Agglomeration—A Case Study of Guangdong-Hong Kong-Macao Greater Bay Area by Using Landsat Data

Table 2

A summary of the assessment of the classification’s accuracy.

Date	Overall accuracy	Sensitivity	Specificity
2012	88.64%	87.71%	88.02%
2017	88.27%	88.67%	87.53%
Average	88.45%	88.19%	87.78%