impervious surface index

And through setting the hypothesis of the impervious surface index distribution map, separately extracts city impervious surface thematic map in 2001 and 1989.
同時對不透水面指數(shù)分布圖進行閥值的設(shè)定，分別提取提取了2001年與1989年的城市不透水面專題圖。