Lu Yuqi

Regional accessibility of land traffic network in the Yangtze River Delta

In a given district, the accessibility of any point should be the synthetically evaluation of the internal and external accessibilities. Using MapX component and Delphi, the author presents an information system to calculate and analyze regional accessibility according to the shortest travel time, generating thus a mark diffusing figure. Based on land traffic network, this paper assesses the present and the future regional accessibilities of sixteen major cities in the Yangtze River Delta. The result shows that the regional accessibility of the Yangtze River Delta presents a fan with Shanghai as its core. The top two most accessible cities are Shanghai and Jiaxing, and the bottom two ones are Taizhou (Zhejiang province) and Nantong. With the construction of Sutong Bridge, Hangzhouwan Bridge and Zhoushan Bridge, the regional internal accessibility of all cities will be improved. Especially for Shaoxing, Ningbo and Taizhou (Jiangsu province), the regional internal accessibility will be decreased by one hour, and other cities will be shortened by about 25 minutes averagely. As the construction of Yangkou Harbor in Nantong, the regional external accessibility of the harbor cities in Jiangsu province will be speeded up by about one hour.

Chinese progress in geomorphometry

Geomorphometry, the science of digital terrain analysis (DTA), is an important focus of research in both geomorphology and geographical information science (GIS). Given that 70% of China is mountainous, geomorphological research is popular among Chinese scholars, and the development of GIS over the last 30 years has led to significant advances in geomorphometric research. In this paper, we review Chinese progress in geomorphometry based on the published literature. There are three major areas of progress: digital terrain modelling methods, DTA methods, and applications of digital terrain models (DTMs). First, traditional vector- and raster-based terrain modelling methods, including the assessment of uncertainty, have received widespread attention. New terrain modelling methods such as unified raster and vector, high-fidelity, and real-time dynamic geographical scene modelling have also attracted research attention and are now a major focus of digital terrain modelling research. Second, in addition to the popular DTA methods based on topographical derivatives, geomorphological features, and hydrological factors extracted from DTMs, DTA methods have been extended to include analyses of the structure of underlying strata, ocean surface features and even socioeconomic spatial structures. Third, DTMs have been applied to fields including global climate change, analysis of various typical regions, lunar surface and other related fields. Clearly, Chinese scholars have made significant progress in geomorphometry. Chinese scholars have had the greatest international impact in areas including high-fidelity digital terrain modelling and DTM-based regional geomorphological analysis, particularly in the Loess Plateau and the Tibetan Plateau regions.

Population movement and the change of regional economy pattern

Population movement is an important phenomenon in China in recent years. Its mechanism is: (1) thrust of more people and less land in the eastern region of China; (2) attraction of dual economy in the western region of China; (3) national policy on preferential wages and grains for the western region. Population movement has an important effect on the change of regional division pattern in China: by the medium of the moving people, there forms another regional division pattern, i.e. rural industry system based on rural town industry; (2) there forms another profit mechanism compensated from the western region to the eastern region. It not only wins more profit in the eastern region, but also changes dual economy in the western region. Therefore, We should make choice of a comprehensible and encouraging attitude on population movement; a special government organization for general survey of the moving people should be set up at once.Population movement is an important phenomenon in China in recent years. Its mechanism is: (1) thrust of more people and less land in the eastern region of China; (2) attraction of dual economy in the western region of China; (3) national policy on preferential wages and grains for the western region. Population movement has an important effect on the change of regional division pattern in China: by the medium of the moving people, there forms another regional division pattern, i.e. rural industry system based on rural town industry; (2) there forms another profit mechanism compensated from the western region to the eastern region. It not only wins more profit in the eastern region, but also changes dual economy in the western region. Therefore, We should make choice of a comprehensible and encouraging attitude on population movement; a special government organization for general survey of the moving people should be set up at once.

The natural basis of the formation of the dual-nuclei structural model

The dual-nuclei spatial structure is composed of a regional central city, a port city and their spatial relations in certain regions. In general, this spatial structure could be found in most of the coastal regions or regions along big rivers. In terms of the mechanism, the dual-nuclei structure is the result of the spatial interaction and the complementary characteristics of the center city and the port city. The ‘marginal function’ of the port city and its relationship with the central city has long been discussed in the literature. On the one hand, drainage area is the main natural geographical background of the formation of the dual-nuclei spatial structure; therefore, we can build a theoretical geographic structure that is based on the drainage area. On the other hand, vicissitude of the coastline also has important influence on the formation of the dual-nuclei spatial structure. It is especially meaningful if we can notice this when we examine deeply the research on the spatial structure of delta.The dual-nuclei spatial structure is composed of a regional central city, a port city and their spatial relations in certain regions. In general, this spatial structure could be found in most of the coastal regions or regions along big rivers. In terms of the mechanism, the dual-nuclei structure is the result of the spatial interaction and the complementary characteristics of the center city and the port city. The ‘marginal function’ of the port city and its relationship with the central city has long been discussed in the literature. On the one hand, drainage area is the main natural geographical background of the formation of the dual-nuclei spatial structure; therefore, we can build a theoretical geographic structure that is based on the drainage area. On the other hand, vicissitude of the coastline also has important influence on the formation of the dual-nuclei spatial structure. It is especially meaningful if we can notice this when we examine deeply the research on the spatial structure of delta.