Developing Integrated Index for Evaluating the Urban Natural Environmental Quality from Remote Sensing Technology

Abstract

Environmental quality (EQ) has always been paid more attention in big cities, where urbanization is on the rise because it greatly affects urban natural ecosystems and people’s health. The paper presents the results of applying Landsat satellite images to evaluate the Natural Environmental Quality (NEQ) from the integrated index NEQI (Natural Environmental Quality Index) through the calculation of biophysical variables, including vegetation index NDVI, water surface index NDWI, construction index NDBI and land surface temperature LST. The study area is the north of Ho Chi Minh City (HCMC), divided into 3 sub-regions for analysis, including 13 old inner-city districts, 6 new inner-city districts, and 4 suburban districts. The results showed that there is a difference in NEQI between inner and suburban areas. Low NEQI is concentrated in urban areas with high urbanization rate, industrial zones, areas with large impervious surface areas and low greenery density. In the suburbs, in contrast, NEQ is better than in the inner city. If considering by the acquisited time of two satellite images in February of 2005 and 2020, the NEQ of the study area showed signs of decreasing and gradually expanding area from the inner city to the suburbs. Particularly in the suburbs, due to the urbanization process in recent years, there are spontaneous and unplanned development areas, so NEQ has changed towards a decrease. The results of the study can be used to support urban environmental planning and management.