基于主成分-聚类分析法的淮河生态经济带土地生态安全评价研究

Evaluation of Land Ecological Security in Huaihe Eco-economic Zone Based on Principal Component-Cluster Analysis

为了解淮河生态经济带21个地级市土地生态安全状况,找出影响其土地生态安全状况影响因素。本文选用了18项指标建立土地生态安全评价指标体系,采用主成分分析法计算2008-2017年淮河生态经济带面板数据土地生态安全综合指数值,同时使用聚类分析法对研究区域各地级市进行土地生态安全等级划分进而深入研究。(1)2008-2017年,淮河生态经济带土地生态安全指数值呈现波动上升的状态,各地级市土地生态安全综合指数也呈现出波动上升趋势,但是区域间差异较大;(2)淮河生态经济带各地级市土地生态安全状况大都是由不安全到逐渐改善,2017年大部分地级市能够达到Ⅲ等级,其中徐州市和扬州市土地生态安全状况排名最高,已经达到安全等级。总体上研究区域土地生态安全状况呈现出"由西向东安全程度逐渐增高"格局;(3)淮河生态经济带21个地级市在聚类分析中分为三类,第一类7个地级市研究期内土地生态安全综合指数F值多为负值,最高也没有超过临界值,第一类地级市和第三类地级市之间的差距比较大。

In order to understand the land ecological security situation of 21 prefecture-level cities in Huaihe Eco-economic Zone and to find out the influencing factors of the land ecological security situation,this paper,selects the 18 indicators to establish the evaluation index system of land ecological security.The principal component analysis method was used to calculate the comprehensive index value of land ecological security of the panel data of the Huaihe River Eco-economic Zone from 2008 to 2017.At the same time,cluster analysis method was used to classify the land ecological security grades of cities at all levels in the study area and further study was carried out:(1)From 2008 to 2017,the value of land ecological security index in Huaihe Eco-economic Zone fluctuated upward,and the comprehensive index of land ecological security of cities at all levels also showed a fluctuant upward trend,but there were great differences among regions;(2)In the Huaihe River Eco-economic Zone,the land ecological security situation of cities at all levels is mostly from insecurity to gradual improvement.In 2017,most of the prefecture-level cities can reach grade III.Among them,Xuzhou and Yangzhou rank the highest in the land ecological security situation and have reached the security level.Generally speaking,the land ecological security situation in the study area presents a pattern of"increasing security degree from west to east";(3)In cluster analysis,21 prefecture-level cities in Huaihe Eco-economic Zone are divided into three categories.In the first category,the F value of the comprehensive index of land ecological security of seven prefecture-level cities is mostly negative,and the highest value does not exceed the critical value.There is a big gap between the first category and the third category of prefecture-level cities.