Correlation Analysis of the Changes of Land Use Structure and Land Use Efficiency
嘉鱼县土地利用结构与效益变化的耦合效应分析

Land use efficiency is one of the primary fields in land use study as it is an essential indicator for land use assessment. Land use efficiency refers to the direct outputs or effects brought by the land use process. Land use efficiency is an integrated concept comprising three sub-systems, which are economy, society and ecology. One important component of improving land use efficiency is the optimization of land use. Spatial-temporal analyses of land use structure and land use efficiency are useful for addressing the problems related to the rapid urbanization in China. Based on information theory, the changes in information entropies of land use structure in Jiayu from 1997 to 2007 are generated by using the land use data. The indicator system for evaluating land use efficiency is set up by means of AHP, in which 3 indicators representing economy, society and ecology are included. Finally, with the method of grey correlation analysis, the correlations between land use structure and land use efficiency are studied. The results show that the information entropies and equilibrium degrees of land use structure have increased gradually in Jiayu from 1997 to 2007, and the corresponding index values of land use efficiency have manifested a rapid increase from 0.0428 to 0.7608 in the study area. There are certain logical relations between land use structure and land use efficiency, and the correlation degree is 0.7679. The land use potential of Jiayu County is comparatively large and there is still space for further optimization of its land use structure. According to the actual situation of study area, the standards of correlation degree of land use types are classified into three levels: high (>0.8); secondary (>0.7) and medium (>0.6). The descending order of correlation degree for each land use type is: residential and unattached industrial land (0.8104), garden (0.8087), forestland (0.7405), unused land (0.7264), cultivated land (0.7011), traffic land (0.6714) and water area (0.6672). Land use structure plays an important role in improving land use efficiency with instant and accumulative effects. The information entropy of land use structure maintains a rising-adjusting-rising trend, and the land use efficiency maintains a growing trend according to the changes. In further study, more attention should be paid to the functions of the different spatial combination and land use types distribution in order to improve land use efficiency.