Remarkable environmental changes in China during the past 50 years: a case study on regional research of global environmental change
20世纪下半叶中国地理环境的巨大变化--关于全球环境变化区域研究的思考

More and more attention is paid to the combination of global and regional issues in the sutdy of global environmental change (GEC). The GEC research emphasizes that the global environmental problems should be probed through regional studies. Resources and environmental problems have become one important issues of GEC research. The geographical environment of China has significantly changed during the past 50 years due to the intense anthropogenic activities and the global environmental changes. The main changes of the physical processes and environment elements are as follows: 1) the shift of climate zones in response to global warming; 2) the uneven precipitation changes inducing more floods in southern China and more severe droughts in northern China; 3) serious pollution and enormous demand on materials and energy; and 4) the significant changes in natural hydrological process. As to the geographical patterns, the economic geographical pattern has changed in the process of industrialization, which brought changes as well to the patterns of population, urban system, and supply-demand of natural resources. As a result, the land cover pattern has been greatly modified. The urban and transportation area has expanded quickly and occupied a great deal of farmland, causing farmland reduction in core agricultural area and cultivation increase in marginal agricultural area. The natural forest area is reducing while the forest plantation is expanding. The grassland is shrinking and has seriously degraded. The area of lakes and wetland has decreased, and the sea farming area has remarkably increased. The above-mentioned remarkable environmental changes indicated that some irreversible changes on environmental elements have taken place, and the resources and environment have become key limiting factors to national security. The future development of China is facing critical challenges from various risks on resource and environment issues, e.g. climate risk under the global warming, the risk of farmland and food supplies, the risk of water resources, the risk of energy, the risk of mineral resources, the risk of environmental quality, and the potential risk of some great projects. The geographical environment of China should be studied from the global views.