A Study On The Safety Of Land Resources Based On The Comprehensive Land Capacity

Land resources is the base of the national economy development, the security of which has become an important part of the resources security.With the development of urbanization of our country, the industrial structure and distributiong changes, whiche leads to the changes of urban land command and use structure, furtherly causes the changes in ecological environment and social economy, lastly has an important influence on the human's ability to use the land on demand and human's exsitance conditions.The regional land security is directly related to the sustainable development of the regional economy.It is of great importance to do some research on the regional land security.The land carrying capacity is an new perspective to study the regional land security, whicn mainly analyzes the carrying objiectives.The traditional research emphasizes the carrying capacity of cultivated-land about the food security ande ecological security. Acturally the land economical carrying capacity is also very important, which includes the net value of all kinds of input and output, structure propotion and so on.In accord with the sustainable development, land security is an comprehensive concept, which is the union of nature, economy ande society. The paper evaluates the regional land resources from the aspect of comprehensive land carrying capacity, applys the carrying capacity index to different categories of land security, makes up with the deficiency of current research,enriches the connotation of land security, affords to the references about the rational use of regional land resources.The paper firstly states the basic concepts of land resources security and land comprehensive carrying capacity, analyzes its relations and the main contents, explains the concrete meaning of the three kinds of carrying system. Then congstructs the land comprehensive carrying capacity system by referring to the exsistent research results about the land ecological security and land security, classifies the different levels of land security according to relavant standards in and around the country. Lastly gives an experimental analysis on Huaian City. For the research area, the paper adopts the subjective and objiective methods to determine the proper indexes, using range methods to dimensionless, information entropy to weights, additive model to calculate the three carrying indexes and comprehensive index. At last, the paper cites the obstacle degree to recognize the obstacle factors. The results showed that: the natural carrying capacity for Huaian City falls first and rises later from 1998 to 2004, economical carrying capacity rises wavely, social carrying capacity risely rapidly relatively, the comprehensive carrying capacity rises wavely. The land security degree is between weak security and preferable security, yet in lower level. The main limitations of the land security is low land use diversity, high cultivated-land pressure, low fertilizer intensity, low ratio of input and output, low degree of coordination of water and soil resources, low ratio of the expenditure of science and technology. According to the exsistent problems, the paper brings forward to some suggestions to realize the land security for Huaian City. First, enrich the land use styles and improve its efficiency; Second, gurantee the amount of basic farmland and enhance the cultivated land production potentiality; Third, increase income and reduce expenditure, use the water resourece rationally; Fourth, develop environment protection industry and expand the ecoagriculture; Fifth, increase the devotion of science and technology, improve population quality.