Abstract:
Abstract: To solve the increasingly serious ecological and environmental problems during the urbanization process, reasonable determination of the land use structure and layout in future is the key. And study on land use scenario simulation under different constraints has been important to scientific planning and decision support. Based on the theory of landscape security patterns and GIS method, ecological security patterns were constructed to maintain the basic ecosystem services of Caofeidian new district which including flood regulation, freshwater supply, biodiversity protection and cultural services. And all these patterns were integrated into a comprehensive ecological security pattern with different security levels. The results indicate that the area of the comprehensive ecological security pattern was 1058.80km2, which accounted for about 53.53% of the study area. Among all levels of ecological security patterns, the area of baseline ecological security pattern that was also considered as the forbidden areas for construction was 312.67km2, accounted for about 15.81% of the study area. And the satisfied and ideal ecological security pattern was 308.15km2 and 437.98km2 respectively. Based on the remote sensing data and GIS method, a land use scenario simulation methodology was developed to integrate CA-MARKOV chain and ecological security pattern at a regional scale. Two scenarios were developed to compare the impact of our land use modeling approach. No ecological conservation scenario is a continuation of the current trends and involves only limited constraints on development. The ecological security pattern conservation scenario (ESP conservation scenario) incorporates ecological security pattern conservation network at different levels. The results indicate that under ESP conservation scenario, there is 74.07km2 newly increasing construction land within the range of overall ecological security patterns, while it is 91.54km2 less than no ecological conservation scenario. An increase of 17.47km2 indicates that the ecological security patterns were effectively protected under the ESP conservation scenario. Especially within the range of baseline ecological security pattern, the quantity of newly increasing construction land is 0 under ESP conservation scenario, while it is 31.07km2, indicating an entirely conservation of baseline ecological security pattern under ESP conservation scenario. Comparative analysis of each scenario with landscape metrics indicated that under the ESP conservation scenario, the number of urban patches increased, indicating that a slightly more fragmented landscape. The value of the Shannon's Diversity Index (SHDI) for no ecological conservation scenario and ESP conservation scenario does not change because under both scenarios the number of classes remains the same, and there are no significant differences in the proportional distribution of the area covered by each land use class. The values of the Shannon's Evenness Index (SHEI) are a slight increased under ESP scenario suggests that the landscape composition has become more even, indicating a transition from a dominant land cover class towards a more diversified landscape. PSCoV for cultivated land, water, beach and saltern changed little under both scenarios, but PSCoV for construction land was obviously increased under no ecological conservation scenario, suggests that under no ecological conservation scenario there are some consolidated urbanized areas in which some intra-urban open space are gradually built out, thus creating some larger urban patches and significant variability in patch size.