城镇化背景下区域土地利用结构的时空变化研究——以衡阳市为例

应用Shannon等人提出的Shannon熵理论,研究衡阳市土地利用结构信息熵的动态演变与空间差异分布规律及其成因。结果表明,该市土地利用结构信息熵值较全国水平低,具有时间上的动态性,在研究年限内呈单调递增趋势,土地利用系统向无序方向发展;在空间上,城市及城郊类型区的土地利用结构信息熵最大,其次是中部岗平类型区、北部丘岗类型区和东南部山丘类型区,南岳旅游类型区信息熵值最小;各个县(市)、区之间土地利用结构信息熵也具有明显差异。衡阳市城镇化与城市工业化的发展以及农业产业结构调整所导致的建设用地的增加和农业内部土地利用类型面积的转变是影响该市土地利用结构信息熵动态变化的主要因素,而建设用地、林地所占比重的高低是影响该市土地利用结构信息熵空间分异的直接原因。

Study on Dynamic Changes and Space Differentiation of Information Entropy of Land Use Structure——A Case Study of Hengyang City

The paper introduces the method of Shannon to analyze the land use structure in Hengyang City so as to reflect the dynamic changes and transformation degree of land use type and space differentiation.If the vaue of entropy is higher,it indicates that the order of the system is worse,and,in turn,its structure will be proved illogic,too.As is well known,land is an integrated system,which has structural and functional dynamic and serial character,which can be shown by the information entropy.To define the serial character,a method was found by Shannon to analyze and reflect the dynamic changes and transformation degree of land use type,taking the land use structure in Hengyang City as an example.As a matter of fact,the value of information entropy of the land use structure in Hengyang City is rather lower in comparison with the level of our whole country,namely,took on the dynamically temporary nature.That is to say,its present flat increase is done by degrees in a fixed rate from 1994 to 2001,whose land use system is proved in the bad serial.In terms of space,land use structure differs from destrict to district in Hengyang City:the information entropy of the land use structure in the City Proper and its suburbs is the highest,those in the hillock flat region in the center,the mond hillock region in the north and hillock region in the southeast follow and that in the tourist scenicregion of the Southern Mountain in the north is the lowest.The information entropy of land use structure varies significantly with the county(city),district..It is main factor of dynamic change of information entropy of land use structure that the increase of construction land and the transformation of agriculture land caused by urbanization and city industrialized development and agricultural industrial structure adjustment in the Hengyang city,and the proportion of construction lan and forset land is an immediate cause of space differentiation of information entropy to land use structure to this city.