The Research About The Optimization Of Gannan Prefecture's Urban System Structure And Spatiotemporal Changes

Urban system, refers to a relatively complete in the area, by a different division of functions, different levels of scale, closely linked and interdependent set of urban form. Gannan is located in the northeastern margin of Qinghai-Tibet Plateau, Yellow River, Yangtze River, is an important area of green ecological barriers; located at the junction of three provinces in Tibetan, is an important multi-ethnic religious and cultural areas; the whole is far from the center of the world economy and China Participation in the globalization of the main channel and the direction of the land-locked region. As the overall economic and social development lagging behind the developed regions, the slow process of urbanization, the effects of radiation from the central city and natural development of the urban system has not yet formed. State there are large areas within the area nature reserves, ecological vulnerability is relatively high, urban development, protection of soil and water resources are weak; the local economic structure of traditional agriculture and animal husbandry, low level of conversion, polarization effects are more obvious, Urban development in space will also feature on the long-standing imbalance. As the state policy of support for Tibetan areas increased, along with the western development of this important period of strategic opportunities to study how the regional specificity for the Gannan, build harmonious development of the urban system, social and economic development of Gannan Prefecture has Significance.Paper is divided into four parts, seven chapters on the structure of urban system in Gannan Prefecture evolution and optimization studies.The first part is an introduction section. Mainly from the macro and micro parts of the paper describes the background, the paper illustrates the significance of the topic, the research progress of urban system at home and abroad, and thesis writing ideas, methods, and frameworks;The second part is the theoretical part. Introduced the basic concepts of Urban system, and the relevant theoretical. Basic concepts include: the concept and characteristics of towns, the concept of urban system, characteristics and structure; basic theory include: theory of city size distribution, spatial structure, evolution theory, theory of urban system development stage.The third part includes the content of Chapter three to Chapter six, and it is the core of the paper. Chapter three about the Gannan history and evolution of urban system evolution features are described and found that the development of urban system through the the birth period - an isolated period of development - shaping the development period.Chapter foure is based on the scale of hierarchical structure functional structure, status of spatial structure analysis of the Gannan urban system. Respectively, summed up the hierarchical structure of the scale of the Gannan urban system is characterized by: The Rating scale of the urban system was first distribution; Counties and towns's first distribution system was significantly; Jurisdiction and the county town of small-scale level of urban uneven distribution of different levels of urban form changes significantly, the average size of small cities and towns, the scale effect is difficult to play; functions of the structural features are: central city functions more prominent position, function class was First type, The functions of a single town, not clear division of functions, administrative functions of the highlights; spatial structure features are: Urban distribution along the river, the distribution lines, two north and south, urban distribution of different forms, the space is divided into north, southwest and southeast of three, the development Clear differences between the status quo;Chapter five analyzes the status quo based on economic, political, environmental and other aspects of the development of urban system analysis of the conditions of Gansu, the main driving force from the regional economy, national security policy and resource environment supportive force discusses three aspects;Chapter six is the architecture of Gannan prefecture town optimization study, pointed out the guiding ideology of the urban system development, strategic models and the corresponding optimal strategy.The fourth part is conclusion. Include the full text of Chapter seven of the concluding summary of the paper that the innovation and deficiencies.