江汉平原生态系统服务价值变化解析

摘要

In order to explore the optimization strategy of regional ecological system,the Jianghan Plain of Hubei Province is taken as an example,using AHP method,LMDI decomposition model based on expert knowledge,focusing on land utilization characteristic of this area and factors affecting the ecosystem sys-tem service value changes.The result shows that:(1 )since 1995,the area of cultivated land,forest land, grassland and natural reservation has been reduced,and the area of water and construction land has in-creased,land-use structure which takes cultivated land and water area as main part is steady;(2)using AHP method based on expert knowledge,value density coefficient correction in different periods is deter-mined,finding that correction coefficient which takes 2007 as a benchmark presents growth trend with time;(3)The calculation method of improved ecological service value is used to find that class ecosystem services values in various regions have all increased,class value contribution in various regions in different periods is characterized by most cultivated land and water area,forest and natural reserve ranking second, construction land and grassland being least;The decomposition effect of ecological service value change u-sing the LMDI model is researched,showing the increase in population,land structure change and impro-ving the value density with value-added effect,effect proportion on the change of the value is respectively 13.12%,9.23% and 90.70%;the decrease of per capita land area has the reducing effect for value change, the proportion is -13.06%,offsetting the appreciation effect of the 3 factors to a certain extent.%以湖北省江汉平原为例,采用基于专家知识的AHP方法、LMDI分解模型等重点考察该区域土地利用特征及生态系统服务价值变化的影响因素分解问题.研究结果表明:(1)1995年以来该地区耕地、林地、草地和自然保留地面积减少,水域和建设用地面积增加,以耕地和水域为主的用地结构变化相对平稳;(2)采用基于专家知识的AHP方法确定不同时期的价值密度修正系数,发现各地类修正系数均以2007年为基准呈现随时间增长的趋势;(3)利用改进的生态服务价值计算方法,发现各地类生态服务价值均有所增加,不同时期各地类价值贡献基本呈现耕地、水域最多,林地、自然保留地次之,建设用地与草地最少的特征;(4)利用LMDI模型考察生态服务价值变化的分解效应,研究显示人口增加、土地结构变化与价值密度提高具有增值效应,对价值变化的效应比重分别为13.12%、9.23%、90.70%;人均土地面积降低对价值变化具有减量效应,所占比重为-13.06%,在一定程度上抵消了三类因素的增值效应.