Assessing Urban Environmental Quality Change of Indianapolis, United States, by the Remote Sensing and GIS Integration

Timely and regular information on urban environmental quality (UEQ) is essential for urban planning. This research evaluated the ten-year UEQ changes in Indianapolis, Indiana, U.S.A, based on the synthetic indicators of physical variables extracted from remotely sensed images and socioeconomic variables derived from census data. Physical environmental variables such as land use and land cover data, land surface temperature, normalized difference vegetation index, and other transformed remote sensing variables were derived from the two Landsat images taken in 1991 and 2000. Socioeconomic variables including population density, house characteristics, income, and education level were extracted from US census 1990 and 2000 block group (BG) data. Correlation analysis and factor analysis were performed after the two groups of variables were integrated at the BG level. For each year, four factors were identified and interpreted as greenness, crowdedness, economic status, and scenic amenity. By assigning different weights to each factor, two synthetic UEQ indexes were generated. A comparison of the two synthetic indexes revealed significant changes in UEQ pattern from 1990 to 2000.