耕地生态安全评价及时空格局分析——以传统农业区河南省周口市为例

Eco-security Evaluation of Cultivated Land in Traditional Agriculture Area and Its Spatial and Temporal Pattern Analysis

针对传统农业区内耕地生态安全状况,以河南省周口市为研究区域,基于人与耕地相互作用机理,运用改进的PSR模型构建适用于研究区域的评价指标体系,采用组合赋权法和多因素综合评价法,对2001-2013年间全市及下属10个县区的耕地生态安全水平进行时空格局分析,结果表明:(1)从时间尺度上看,周口市耕地生态安全综合值呈现出"下降—上升—下降—上升"的波动变化且安全值相对较低,相应的安全等级也经历了"较不安全—临界安全—较安全—临界安全"的倒"U"型发展阶段.(2)从空间尺度上看,各县区耕地生态安全状况存在着明显的地带性差异.安全和较安全区主要集中在周口市的中部和西南部地区,并随着安全状况的变化向东部、北部扩展或缩减;临界安全区的分布变动幅度较大,但主要集中在周口市北部、东部和南部6个县区;较不安全和不安全等级仅在2001年和2003年有所分布.2001年较不安全区主要集中在南部的项城和沈丘,但随着环境的继续恶化,到了2003年,该分布范围蔓延到了东北部的郸城和鹿邑,并且项城沦为了研究期内唯一的不安全分布区.

Aiming at the ecological security of cultivated land in the traditional agriculture area and taking Zhoukou City in Henan Province as a study area,based on the interaction mechanism between human and cultivated land,the space-time pattern analyses of the ecological security level of cultivated land in the city and its subordinate 10 counties from 2001 to 2013were performed by using the improved PSR model to build the evaluation system applied to the study area as well as the combined weight and multi-factor comprehensive evaluation methods.The main conclusions are as follows：（1）from the time scale,the comprehensive security value is relatively low,showing a trend of＂down-up-down-up＂,and the corresponding security level go through the inverted U-type development stage of＂less safety-criticality safety-more safety-criticality safety＂;（2）from the spatial scale,there is a clear difference in the ecological security of cultivated land in different counties.The safer areas are mainly concentrated in the central and south-western regions,along with the expansion or reduction towards the eastern and northern areas as the security situation changes.Distribution range of the critical zone is very large,but it is mainlyconcentrated in 6counties located in the northern,eastern and southern areas.The unsafe grade distributions only occur in 2001 and 2003.In 2001 the unsafe areas are mainly focused on the southern Xiangcheng and Shenqiu,continuing to worsen as the environment changes.In 2003,the unsafe areas spread to the northeastern Dancheng and Luyi,and Xiangcheng becomes the sole unsafe area in the study period.