基于GIS的沿海地区生态安全时空测度与演变研究——以大连市瓦房店为例

Abstract

In this study,taking the Landsat TM remote sensing images( track No. 120 /32,120 /33) of Wafangdian County-level City in 2000,2005 and 2010 as the data sources,the coastal ecological security evaluation system was established on the basis of landscape pattern analysis and pressure-state-response( P-S-R) framework. Grid database of coastal eco-security assessment was created by quantitative multi-source data with GIS grid technology. Eco-security status was estimated by the use of the weighted-fuzzy membership degree method. Temporal and spatial evolution of eco-security pattern was analyzed through spatial statistical methods in order to reveal evolution features of coastal region ecological safety as well. The results showed as follows: 1) The ecological safety index of Wafangdian County-level City from 2000 to 2010 was 0. 4636,0. 3878 and 0. 4636,respectively,which demonstrated eco-security situation had a slight improvement after deterioration,but we should pay more attention to prefect the ecological status in western coastal district. 2) Moran's I from2000 to 2010 was 0. 9015,0. 8738 and 0. 8703,respectively,which indicated there was a significant correlation of spatial evolution in the space. The characteristic of ecological safety pattern was that areas with high value was inclined to be close to the regions of better ecological eco-security status,while the low degree of eco-security status presented adverse tendency,which performed extremely obvious from 2000 to 2005. 3) The nuggets of eco-security index in Wafangdian County-level City was 0. 0030,0. 0007 and 0. 000903,respectively,which showed the non-structural factors played an everincreasing role in spatial distribution of ecological safety in the study area,which was consistent with the actual conditions of urban construction land expansion and frequent human activities in the past decade. The change about value of C0/( C0+C) decreased as the speed increased initially and decreased afterwards,which reflected the impact of non-structural factors on the space differentiation of ecological security had experienced a consistent change trend. With the implementation of the land policy and management of Dalian City,the influence from non-structural factors such as urban construction and human activities on eco-security evolution has been cut down since 2005.