Spatiotemporal Evolution of Urban Green Space and Ecological Quality in Beijing-Tianjin-Hebei Region

Abstract

Urban development in the future is more manifested as the development of urban clusters, and the regional ecological quality is an important basis for its ability to maintain sustainable development. On the basis of the three phases of MODIS remote sensing data from 2000 to 2020, we quantitatively analyzed the spatial and temporal dynamics and evolution of land ecological conditions in Beijing-Tianjin-Hebei region under the background of urbanization by dividing urban green space and constructing a remote sensing ecological index RSEI model, supplemented with trend analysis. Results indicated that (1) The major green spaces in Beijing-Tianjin-Hebei region are medium and high vegetation density areas and show an increasing trend year by year. With the increase of urban gray space as well as artificial green space, the area converted to no vegetation cover area and low vegetation cover area also increases, accounting for 13.58%. (2) The overall trend of vegetation density is increasing and can be divided into three gradients, with the first gradient being three cities, Zhangjiakou, Chengde, and Baoding, accounting for 61% of the whole rising area. The transition types with decreasing vegetation density are mainly found in cities with higher urbanization levels. (3) The ecological status has been improved significantly in the east and south, showing a slow decreasing trend in the mid-west, north, and some urban centers. The ecological status is elevated when positive conversion occurs and decreases when negative conversion occurs, and the rate of decrease (0.038 5/a) is higher than the rate of elevation (0.026 1/a). The results can provide scientific data and theoretical basis for the rational development and scientific management of green space in the Beijing-Tianjin-Hebei region, and have practical significance for the sustainable and coordinated development of regional economy, society, and environment.

Keywords

• urban green space
• rsei
• spatiotemporal change
• urbanization