Study On Spatiotemporal Relationship Between Intra-urban Ecological Land And Ecological Resilience

The continuous advancement of the urbanization process has led to the double contradiction between urban economic development and ecological environmental protection.As the urban commercial center and population gathering place,the interference of human activities to ecological land increasingly affects the structure and function of the ecosystem,threatens the urban ecological security,and restricts the sustainable development of the city.Urban ecological resilience is a further deepening of the research on urban ecological security and sustainable development,which provides new ideas and solutions to solve the conflict between urban rigid development needs and ecological environmental protection.Wuhan is a core city of the Yangtze River Economic Belt in China with rapid urbanization.Within the Third Ring Road of Wuhan is the core area of economic development and population distribution,and it is also the concentration area of ecological problems.Taking the Third Ring Road of Wuhan as the research area,the main land cover types were identified by high resolution remote sensing images in 2000,2010 and 2020.Taking the block scale as the unit,the temporal and spatial change characteristics of intra-urban ecological land were represented by the quantity,distribution and landscape pattern from 2000 to 2020.Based on the basic characteristics of ecological resilience,the ecological resilience was evaluated from three aspects:ecosystem resistance,adaptability and restoring force.Based on the change of ecological land on the block unit,the sensitivity analysis of ecological resilience and ecological land was carried out to reveal the internal correlation between ecological land change and ecological resilience.The results showed that:(1)The total area of ecological land showed a downward trend from 2000 to 2020,with a total loss of 47.82 km~2,mainly caused by the reduction of cultivated land,while the area of woodland and grassland increased significantly.The decrease area of ecological land was located in the newly built area near the Third Ring Road,while the increase area of ecological land was located in the internally built-up area.The fragmentation of ecological land was generally increasing in recent twenty years,and there was significantly spatial difference.The area with increased fragmentation was mainly located in the surrounding new built area,while the fragmentation was moderated in the internally built-up area.(2)The overall ecological resilience of the study area was at a medium level from2000 to 2020,and showed a slight upward trend,with a gradual trend of development and change for the better.The ecological resilience presented a stable spatial distribution pattern of low center and high periphery.In 2000-2010,the resilience increased in the southwest of the study area and part of the center.In 2010-2020,the ecological resilience generally showed the evolution characteristics of increasing in the north and decreasing in the south.In general,the ecological resilience was mainly increased in the built-up area and decreased in the surrounding new built area.(3)Ecological resilience was low sensitivity to ecological land area changes,which was mainly reflected in the simultaneous decrease of the surrounding new built area and the simultaneous increase of the internally built-up area.From the perspective of different ecological land use types,the low sensitivity of ecological resilience to cultivated land and water area was mainly decreased synchronously,which was mainly located in the surrounding new built area.The low sensitivity of ecological resilience to woodland and grassland mainly showed that both increased synchronously,which was mainly located in the internally built-up area.From the perspective of landscape pattern index,the ecological resilience was more sensitive to AI,and the low sensitivity to PD and LSI was mainly reflected near the water area.