人类关键区的科学逻辑与研究趋势

人类关键区是人类社会进入人类世时代，人类所创造的地表景观在地理圈层中的特征区域。人类近万年历史对人地关系的认知可分为人类文明与地球环境、人类活动与地理环境、空间行为与土地利用3个层级。人类关键区具有全球尺度、国家尺度、区域尺度、地方尺度以及社区尺度。全球尺度的人类关键区可划分为建成区、农业区、生态区、裸露区。人类关键区未来的研究主要包括人类关键区的识别，人类关键区物质循环与能量流动，人类关键区耦合机理与动力机制，人类关键区地理模拟（器）与调控决策。人类关键区的提出为全球可持续发展提供中国地理科学的创新理论与实践路径。

The Scientific Logic and Research Trends of Human Critical Area

Human activities have become a forceful geological agent on the Planet by rapidly and dramatically altering the natural world, which, in turn, is affecting the well-being of humans themselves. The cumulative impact of human activities on the Planet has driven an ever-evolving human-land relationship and left recognizable marks on the Planet’s surface, i.e., the human critical area (HCA), which is an area that characterizes the surface landscape created by human beings in the Anthropocene. It is a relatively homogeneous area of human activities within the geosphere and the basic unit of the human-land coupling system. Human’s perception of the human-land relationship over its nearly 10 000 years of history can be divided into 3 layers: human civilization and the earth’s environment; human activity and the geographical environment; and spatial behavior and land use. As the imprint mainly dominated by human activities on the earth’s surface, the HCA has a temporal-spatial attribute, showing in global, national, regional, local, and community scales. Each scale is with its types, structures, and expression forms. Specifically, the HCA on the global scale can be classified into the built-up area, agricultural area, ecological area, and bare area; the HCA on the national scale can be divided into the elemental area, functional area, and administrative area; the HCA on the regional scale can be classified into the ecological area, economic area, poverty area, and urban area; the HCA on the local scale can be divided into the small city, town, and village; the community-scale HCA can be classified into the block, residential building, and other geographical units. Further discussion on the HCA should focus on the followings: 1) identification, demarcating an objective spatial area that reflects the results of interactions of human-land through the analysis of factors (e.g., land use, transportation network, population density, economic level, night light, etc.) or the applications of deep learning and big data with the development of geospatial technology; 2) material cycle and energy flow, exploring the material circulation and energy flow in different types and scales in this key interface; 3) coupling mechanism and dynamics, exploring the rules and principles of element coupling, interface coupling, space-time coupling, scale coupling, system coupling, etc., as well as understanding the processes and manifestations of diverse dynamics over the evolved period of human to achieve coordination among subsystems; 4) geo-simulator and regulatory decision making, comprehensively simulating, analyzing, predicting, and optimizing the human key area with virtual simulation experiments. The HCA can provide an innovative theoretical and practical path for global sustainable development in the geoscience of China.