长沙市土地利用生态风险及评价

摘要：城市生态环境问题已成为制约城市可持续发展的重要问题,土地利用变化是城市生态环境改变的重要因素。长沙市作为中部经济发达、人口众多的大城市，其工业化和城市化的发展速度很快。强烈的土地需求对土地利用的强度、方式、规模、布局等造成了深远的影响，同时也对城市生态环境造成强烈的冲击，生态安全受到严重威胁。本文引入城市土地利用生态风险评价的概念，分析长沙市土地利用现状，阐述城市土地利用生态风险产生的原因，识别与土地利用相关的生态环境问题，综合运用主成分分析，K均值聚类等方法，建立了土地利用生态风险评价模型，分析和评价长沙市土地利用生态风险。结果发现该区所研究时段土地利用生态风险总体上变大，土地利用生态风险值从1996年的-0.85286（Ⅴ），变为2006年的1.321039（Ⅰ），期间变化波动明显，风险值在1996-1999年和2003-2006年趋于上升，2000-2002年趋于下降。根据此评价结论提出一系列规避和应对生态风险，协调城市土地利用与生态环境的对策。

A Study on Urban Land Ecological Risk and Its Evaluation in Changsha City

Ecological environment is a very important factor in controlling continuous economic development in the world.Changsha,as a developed and populous metropolis,has witnessed a fast advance in economy and a great change in city construction.The strong needs of land will surely make huge impact on the intension,mode,scale,distribution of land use,bring strong impact to the ecosystem environment,and threat ecosystem safety seriously.The authors expound the concept of urban land ecological risk assessment,account for the urban land ecological risk.Then,the authors analyse the current eco-environmental situation,identifying some ecological environment problems related to land use.By utilizing principal component analysis and K-means clustering,a model for urban land ecological risk assessment is proposed,and the authors analyse and evaluate the ecological risk,and study how to deal with it.The research results are as follows：（1） Changsha city urban land ecologically use risk level has wholly been rising from 1996-2006,the evalue of risk is-0.85286 （Ⅴ） in1996,whereas the value of 2006 is 1.321039 （Ⅰ）,corresponding to a declining in 2000-2002 and a decrease in 1996-1999,2003-2006;（2） the conclusion signifies that Changsha city land utility isn ＇ t in accordance with eco-environment amelioration,therefore,it is also necessary to adopt a series of countermeasures to coordinate the relations between Changsha land use and ecological environment,promote the sustainable development of land use and ecological environment.