RS/GIS-Based Assessment and Analysis of Ecological Security Dynamics in the Suburbs of Beijing

In this paper, the temporal and spatial dynamic trend of ecological security in the suburbs of Beijing from 1996 to 2005 is analyzed in terms of landscape ecological security index (ESI), on the ground of landscape ecology theory and the stability of landscapes. Semivariogram analysis and Kriging interpolation are conducted to get the distribution map of ecological security. The results show that: (1) The landscapes in the study area from 1996 to 2005 changed in different trends, with persistent increase in construction land and substantial decrease in cropland landscape. (2) The landscape indexes of patch number, landscape fragmentation and fractional dimension have all shown an increasing trend in the study area. (3) Human activity has much influence on the ecological security index, giving rise to quite uneven spatial distribution of ecological security in the whole area. (4) The ecological security index (ESI) can be used to quantitatively evaluate the ecological environment and its evolution direction. The ESI takes on an ascending tendency from Chaoyang District through Shunyi to Miyun counties, and the area of low ESI has been expanding gradually with the acceleration of urbanization of Beijing.