Research on the change of Spatio-temporal characteristics of Urban built-up area based on remote Sensing-- A case study of Yulin City, Shaanxi Province

Abstract

Since the reform and opening up, the process of urbanization in China has been at a high level. In order to accurately obtain the boundary of urban built-up area and the spatiotemporal change characteristics of urban built-up area in recent years, this paper takes Yulin City as an example. With the help of ArcGIS, ERDAS and other platforms, we combine spatial comparison method and index method to extract urban built-up area from DMSP-OLS night light data and Landsat image data. At the same time, the confusion matrix is used to verify the extraction boundary. The research shows that: (1) Using DMSP-OLS night light data and Landsat data to extract the built-up area, the overall accuracy can reach 99%; (2) The urban built-up area of Yulin City expanded at a high speed from 2005 to 2018; (3) The urbanization process in the northeast of Yulin City is obviously higher than that in the south in recent years. This study has a certain reference value for the extraction of urban built-up areas and the development of urbanization in Yulin City by using DMSP-OLS night light data and Landsat data.