Studies on the 20th century climate change in China have revealed that under the background of global warming over the past century, climate in China has also experienced significant change with mean annual temperature increased by about 0.5 oC. More reliable results for the latter part of the 20th century indicate that the largest warming occurred in Northwest China, North China and Northeast China, and the warming in winter is most significant. Although no obvious increase or decrease trends were detected for mean precipitation over China in the past half century, regional differences are very distinct. In the middle and lower reaches of the Yangtze River, precipitation increased, while that in the Yellow River Basin markedly decreased. Studies suggest that climate change in China seems to be related not only with the internal factors such as ENSO, PDO, and the others, but also with the anthropogenic effects such as greenhouse gas emissions, and land use. The future climate change studies in China seem to be important in narrowing understanding the nature of China's climate change and its main causes, since it is significant for projection and for impact assessment of climate change in the future.
The temperature appeared rising trend during the 20th century in China's tropics. Two cooling stages and two warming stages in the process of climatic fluctuation can be recognized. After the 1980s the climate is the warmest which corresponds to the global change, but the warmest period is the 1940s in Kunming. The climate pattern mostly appears contemporaneity of warming and humidity, which is different from the situation of whole China. The natural disasters tend to be aggravated. The number of typhoons increased. Flood damages occurred frequently in the years of more typhoons. The number of droughts and cold damages increased. It was snowed in Guangzhou. There was frost in Haikou and Yaxian. Four years of heavy snow have been recorded in Kunming.
China possesses over 110 international rivers and lakes, among which 41 are major ones and 15 are of great importance. With the highest concentration of international rivers, the northeast, northwest and southwest regions of China enjoy abundant transboundary resources and pose complicated ecological security issues. Following the 1950s, relevant studies on international rivers fall into three periods: 1) the planned economy period of the 1950s-1980s when border development and basic research were scant; 2) the reform and opening-up period from 1980 to the end of 20th century. Along with the drive of economic globalization and regional cooperation, development of international rivers was thriving, which filled blanks in the research and narrowed gaps with international standards. Relevant studies also provided national and local governments with important scientific grounds for making decisions; 3) since the start of the 21st century, China has integrated its international river studies across sectors and across international borders. Now both government and scientific institutions pay great attention to transboundary environmental issues.
Soil loss, water shortage, flooding, sedimentation and water pollution are the major problems affecting the sustainable development of the Yellow River basin. Their impacts and management strategies are briefly discussed in this paper. The integrated management strategy, which includes one ultimate goal, four standards, nine countermeasures, and the concept of "three Yellow Rivers," is a contemporary management strategy and represents the vision of the Chinese government and engineers for the sustainable development of the Yellow River basin.
China is a country abundant in lakes. Lake science development in China, not only aims at the international frontiers of correlative subject development, but also focuses on the national strategic needs in different ages. This paper describes the general situation and distribution characteristics of Chinese lakes, systematically reviews development process of Chinese lake science and its progress in lake physics, lake chemistry, lake biology, lake sediment and lake-watershed management, finally looks forward to the developing tendency of Chinese lake science in future.
Traditional wetland study in China mainly focuses on mire resources investigation and utilization. At present, environment, resources problems and sustainable development theory have infused new driving force into the wetland development. Since wetlands have huge ecological and environmental functions, they are paid more and more attention to by academic circles. The key field in wetland study at present is the natural process of wetlands, including hydrologic process, biogeochemical cycle process, and biological process, the relation between wetlands and global changes, wetland function evaluation and wetland rehabilitation. The paper reviews the main study progress of wetlands in China, analyses the present situation of wetland researches in China, and puts forward the main direction of wetland science researches in China.
Under the framework of Chinese Soil Taxonomy, all the 14 established soil orders including Histosols, Anthrosols, Spodosols, Andisols, Ferralisols, Vertisols, Aridisols, Halosols, Gleyosols, Isohumisols, Ferrisols, Luvisols, Cambisols and Primosols, forming a complicated pedodiversity pattern resulted from both various natural conditions and long history of human activities, are introduced with brief descriptions. At the end of the paper, the selected references in English are listed for foreign readers to get further information in detail if needed.
Progress in Chinese loess research made in recent 15 years was introduced in this paper, including mainly distribution and paleoenvironment significance of Chinese loess, new development of loess formation age, red-brown paleosol types and environmental change, loess-paleosol sequence and climate cycles, monsoon strength change during last interglacial and last glacial periods in the Loess Plateau, climate events, and source areas of loess and material.
The fractal theory put forward by American mathematician B B Mandelbrot (1967) supplies an effective approach to solve complex problems. The complex problems in geography have become the main positive study field of fractal theory. Based on the works of China's geographers and the summarization of contents of fractal theory, the authors comment on the present situation of its applications to almost every branch of geography and discuss the related problems and the prospects of fractal study in geography.
This paper describes the current situation of China's land use and land use changes, major driving forces, and their impacts on the environment, through a review on land use studies in the past decades in China.
Over the past several decades, no less remarkable than the fast economic advance has been the pollution of water, air and soil all over China. The degradation of environment provides challenge as well as opportunity to the native scientists. Benefited from their regional-scaled views and unique tools of study, Chinese environmental geographers distinguish themselves from other environment-related scientists by combining geographical methodology with means of chemistry and biology and by emphasizing region-based processes of pollutants and scaling issues. Additionally, they are benefited from the basic trainings in the branches of physical geography, such as soil geography, hydrology and climatology for a better understanding in behavior of pollutants in nature.
The construction of nature reserves in China is reviewed in this paper, mainly including the number, type, administration and distribution of nature reserves, the progress in research on biodiversity, evaluation, management, sustainable development of nature reserves in China is summarized briefly, and some development tendencies of research on nature reserves are put forward.
About 70% of its land area as mountains and plateaus, China is the largest mountain country in the world. Thanks to its vast territory (9.6 million km2), outstanding relief and varied climates, China boasts extremely plenty of ecosystems and landscapes. From south to north, it traverses almost all the temporal zones from tropical rainforest in the southernmost to frigid-temperate needle-leaved forest in the northernmost; from east to west, it sees a gradual transition fro humid forest landscape to extremely arid desert landscape; vertical change of landscapes is most striking owing to the existence of many high mountains (above 6000-7000 m, e.g., the Himalayas, the Kunlun, the Tianshan, the Hengduan, etc.) and plateaus, especially the immense Tibetan Plateau (averagely 4500 m above sea level). All of this give rise to the richness and diversity of ecosystems and landscape in China. Some of the ecosystems are endemic to China, e.g., alpine desert and alpine steppe in the Tibetan Plateau. As a result, China bears a great responsibility in the protection of global ecosystems and landscape.
In the 1950s, research on natural regionalization for highway was set out in China. This paper reviews its history and introduces the relative research in other countries. Based on the comparative analysis of the different research angles among different countries, suggestions about the future work are offered. The relations between physiographical indexes and the indexes directly related with highway engineering are suggested to be studied and the basic data for highway be tested and collected all over the country. These works will be of help to the guidance of regionalization for highway engineering. And the impact of highway on the geographical environment should also be considered in highway natural regionalization.
