基于TM图像的“增强的指数型建筑用地指数”研究

A Study of Enhanced Index-based Built-up Index Based on Landsat TM Imagery

以Landsat TM/ETM+图像为数据源,研究城镇和农村建筑用地信息的提取方法。首先利用TM 7,4,2波段创建归一化差值裸地与建筑用地指数(normalized difference bareness and built-up index,NDBBI);然后根据裸地在裸土指数(bare doil index,BSI)图像上的亮度值最高、在改进型归一化差值水体指数(modified normalized differencewater index,MNDWI)图像的亮度值最低的特征,提出了增强型裸土指数(enhanced bare soil index,EBSI);最后选用NDBBI,EBSI,MNDWI和SAVI(soil adjustment vegetation index,SAVI)4个指数,构建一种新型的建筑用地指数,称为"增强的指数型建筑用地指数"(enhanced index-based built-up index,EIBI),可快速地提取建筑用地信息。实验结果表明,用EIBI提取的建筑用地信息客观,人为干预少,可信度高,提取精度可达90%以上,适合于同时提取城市和农村建筑用地信息。

A new method for extraction of built-up land information both in suburban area and in urban district by using Landsat TM/ETM＋ imagery is proposed in this paper.Firstly,to suppress the information of bare soil with the middle-infrared（TM7）,near-infrared（TM4） and green band（TM2）,it is necessary to build a secondary index,which is called normalized difference bareness and built-up index（NDBBI）.At the same time,to enhance the information of bare soil from existing indices of bare soil index（BSI）and modified normalized difference water index（MNDWI）,another secondary index is built,which is called enhanced bare soil index（EBSI）.Finally,the indices of NDBBI,EBSI,SAVI and MNDWI are applied to constructing a new index for delineating built-up land features in satellite imagery,which is called enhanced index-based built-up index（EIBI）.The new index（EIBI）can be employed to extract the built-up land information both in suburban area and in urban district.This approach has been successful in Fuzhou and Zhangzhou experimental regions.Built-up features can be extracted objectively and sufficiently with the accuracy above 90%.