Land use based on landscape ecological security pattern provides a scientific basis for alleviating conflicts between land conservation and human use, ensuring concomitant economic development and ecological integrity. The majority of studies by Chinese researchers have been focused on the carrying capacity and land development intensity, and less attention has been paid to the ecological security pattern of the landscape in Mianzhu in the transitional zone between the Chengdu Plain region and the Longmen Mountains, western China. However, land resources are undergoing significant changes resulting from land use associated with rapid economic development and demographic growth. In this study, we constructed a minimum cumulative resistance model in Mianzhu in the transitional zone, and the land space was divided into optimized development areas, key development areas, restricted development areas, and prohibited development areas according to the landscape ecological security pattern based on the model surface. These land use types covered 7218.39 ha, 17,974.75 ha, 21,545.39 ha, and 77,791.46 ha, respectively. We also examined land use changes over the last 20 years and quantitatively analyzed the relationships between land use changes and geographic factors based on remote sensing and geographic information system. The information obtained from this research ultimately impacts future policies and plans regarding land resources and can be used to promote the sustainable use of land resources in the region.
Integrated assessment models and coupled earth system models both have their limitations in understanding the interactions between human activity and the physical earth system. In this paper,a new human–earth system model,BNUHESM1.0,constructed by combining the economic and climate damage components of the Dynamic Integrated Model of Climate Change and Economy to the BNU-ESM model,is introduced. The ability of BNU-HESM1.0 in simulating the global CO2 concentration and surface temperature is also evaluated. We find that,compared to observation,BNU-HESM1.0underestimates the global CO2 concentration and its rising trend during 1965–2005,due to the uncertainty in the economic components. However,the surface temperature simulated by BNU-HESM1.0 is much closer to observation,resulting from the overestimates of surface temperature by the original BNU-ESM model. The uncertainty of BNU-ESM falls within the range of present earth system uncertainty,so it is the economic and climate damage component of BNU-HESM1.0 that needs to be improved through further study. However,the main purpose of this paper is to introduce a new approach to investigate the complex relationship between human activity and the earth system. It is hoped that it will inspire further ideas that prove valuable in guiding human activities appropriate for a sustainable future climate. 相似文献
One of the key issues in international climate negotiations is the formulation of targets for emissions reduction for all countries based on the principle of "common but differentiated responsibilities". This formulation depends primarily on the quantitative attribution of the responsibilities of developed and developing countries for historical climate change. Using the Commuity Earth System Model(CESM), we estimate the responsibilities of developed countries and developing countries for climatic change from 1850 to 2005 using their carbon dioxide, methane and nitrous oxide emissions. The results indicate that developed countries contribute approximately 53%–61%, and developing countries approximately 39%–47%, to the increase in global air temperature, upper oceanic warming, sea-ice reduction in the NH, and permafrost degradation. In addition, the spatial heterogeneity of these changes from 1850 to 2005 is primarily attributed to the emissions of greenhouse gases(GHGs)in developed countries. Although uncertainties remain in the climate model and the external forcings used, GHG emissions in developed countries are the major contributor to the observed climate system changes in the 20 th century. 相似文献