Geography is a discipline that studies the spatial distribution patterns, time evolution processes and regional characteristics of geographical elements or geographical complexes on the earth’s surface. It is the intersection of natural sciences and social sciences and has comprehensive sexual, intersectional and regional characteristics. With the development of geographic information technology and changes in research methods, geography in the new era is turning to geographical science. The research theme places more emphasis on the comprehensive study of land surface systems. The research paradigm is experiencing a shift from geographical knowledge description, pattern and process coupling, to geographical knowledge description, pattern and process coupling, to geographical knowledge. Modeling and predicting transformations of complex human-earth systems.

The main research object of geography is the earth’s surface. It is a natural-social complex formed by the interaction and interpenetration of the lithosphere, hydrosphere, atmosphere, biosphere and human wisdom circle.

The upper interface of the geographical research space is the top of the troposphere of the atmosphere, and the lower interface is the upper part of the lithosphere. The earth's surface is the most complex interface on the earth. It is a place where the three states of matter interact, organic and inorganic transform into each other, and where internal and external forces on the earth interact. The earth's internal forces and the earth's internal active tectonics have a significant impact on the earth's surface, and the earth's external forces also have a very obvious effect on the earth's surface. Internal forces such as volcanic eruptions, earthquakes, and plate movements cause plateau uplift and are the internal driving force of the earth. External forces such as water erosion and wind erosion have shaped the various natural forms on the earth's surface.

What is particularly important is that the earth's surface system is the environment on which human society depends for survival. To maintain sustainable human development, we must protect the earth's surface system, especially the land surface system that is most profoundly affected by human activities. Therefore, the study of geography not only involves the extension of matter and energy in the vertical direction, but also involves the extension of matter and energy in the horizontal direction; it includes not only the characterization of natural processes, but also the analysis of humanities and socioeconomic processes. , including the coupling of human and earth systems. Facing many complex comprehensive issues such as resources, ecology, and environment, geography needs to find a comprehensive approach and method to deal with many challenges and lay a disciplinary foundation for sustainable human development.

First, changes in geographical research methods. Traditional geography methods mainly include exploration, observation, recording, mapping, zoning and planning. The early demarcation of zones is instructive in macro aspects for decision support, but further specific and informative information is needed in micro aspects. Modern geography has inherited its original advantages in the development process. While strengthening field investigations and observations, it also pays more attention to the application of spatial statistics, earth observation, geographical information systems, remote sensing and other technical means to establish models and decision support systems. Serves decision-making and management.

Second, geographical research techniques have moved from conceptual models to quantitative expressions. From the early concepts of geographical zonation and K?ppen climate zoning to climate system models, from the early spatial superposition of geographical information to the coupling model of multi-sphere elements of the Earth system, the simulation accuracy of geography-related models is constantly improving. From computer mapping to spatial analysis, geographic information systems are developing towards digital earth systems with different resolutions, massive data, and multi-dimensional displays. From early aerial remote sensing to multi-satellite network multi-resolution, all-weather, full-band, multi-element stereoscopic Earth observation, the spatial and temporal resolution of remote sensing observations has been greatly improved. From early compasses and compasses to networked satellites and then to mobile terminals, the global positioning system has realized the transition from positioning to location services based on mobile networks. With the gradual establishment of a monitoring system for the earth's surface, from aerospace remote sensing in the sky to underground detection, to the observation of surface soil, vegetation, water and other elements, refined and multi-scale field observations have been achieved, providing a basis for studying geographical processes. It provides rich data and deepens the understanding of the processes and mechanisms of geographical phenomena. Geographic research has moved from statistical models to model simulations, from linear analysis to nonlinear mathematical statistics, from model establishment to model systems, and prediction-oriented multi-sphere and multi-element coupled earth system models have become possible.

Third, big data, visualization and virtual reality provide important tools for studying complex geographical issues. Big data can describe spatiotemporal changes in social and economic phenomena in a relatively detailed manner. For example, in the analysis of humanistic phenomena, hot spots are identified through the spatial flow of population, thereby providing scientific basis for the layout of public facilities and the construction of transportation networks; through the combination of indoor simulation and outdoor observation, the geographical process of outdoor observation is The data is combined with digital rainfall, vegetation coverage, urban transportation network layout and other elements to conduct intelligent and visual simulations on computers to provide services for decision-making. Early mapping studies on land cover, land use, soil, etc. were often done manually through field surveys, and survey plots were established to represent different map characteristics. By interpreting the types of surface objects through remote sensing images and relying on the geographical information system to integrate and manage other spatial data, we can realize the core human-land relationship research in geography, such as changes in the spatial pattern of land cover, urbanization processes and their driving mechanisms, etc., and provide Services related to sustainable development issues such as biodiversity conservation, urban and rural planning, and response to global changes. As the interaction model of geographical circles pays more and more attention to the coupling of multiple elements, comprehensiveness and integrity have become the "numerical expression" of geographical concepts, and 3S technology runs through all aspects of solving geographical problems.

For example, in the study of climate model evolution, climate models in the 1970s mainly considered the atmosphere and the earth's surface; it was not until the late 1990s that the impact of aerosols was considered in the IPCC's second assessment report. Later, the dynamic changes of vegetation, atmospheric chemical characteristics, changes in the cryosphere, etc. were gradually considered. In the future, the impact of urbanization, socioeconomic changes, and industrial changes on the climate system will also be added. In short, the interaction model of geographical circles is becoming more and more comprehensive, integrating more and more natural environment and socio-economic characteristics.