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(shí)對(duì)不透水麪指數(shù)分佈圖進(jìn)行閥值的設(shè)定，分別提取提取了2001年與1989年的城市不透水麪專題圖。