西安市都市农业生态安全动态评价及空间分异

Dynamic evaluation and spatial differentiation on ecological security of urban agriculture in Xi'an City

通过构建都市农业生态安全概念及评价指标体系,运用熵值法、障碍度分析模型、GIS制图技术对西安都市农业生态安全进行综合评价。结果表明:西安都市农业生态安全指数从2002年的0.44增加到2011年0.68,生态安全状态明显好转;城市化对都市农业资源可持续能力和系统稳定程度负面影响较大,而对产出持续增长和发展保障能力正面影响更大;近十年来,阻碍西安都市农业生态安全的关键制约因素平均障碍度2003、2006、2011年分别为12.47%、7.05%、4.97%,表明其影响程度在逐渐减弱;西安地区生态安全指数值(S):莲湖、碑林、新城区S≤0.15,蓝田县0.15<S≤0.27,长安区和阎良区S>0.35,其余区县0.27<S≤0.35,表明因西安各地区都市农业生产条件差异、交通便捷程度及与城市经济联系强度差异而呈明显的空间分异。

In this paper,a concept of urban agro-ecological security and its evaluation indicator system are put for-ward,and comprehensive evaluation for urban agriculture ecological security in Xi’an City has been carried out by apply-ing the entropy value method,obstacle degree analysis model and GIS spatial analysis technique .The result shown that：The safe index of urban agro-ecological security has increased from 0 .44 in 2002 to 0 .68 in 201 1,the urban agro-ecolog-ical security conditions were improved obviously .The urbanization have large negative influence to the sustainable ability and system stability of urban agricultural resources,while more positive influence on output sustainable increase and de-velopment ensure ability .In recent ten years,the average obstacle degree of the key factors which impeded the improve-ment of urban agro-ecological security were 12 .47%,7 .05%and 4 .97%respectively in the years of 2003,2006,and 2011,which shown that the obstacle degree has gradually decreased in Xi’an City.The ecological security index in Xi′an Region was S≤0 .15 in Lianhu,Beilin,and Xincheng district,0 .150 .35 was in Chang’an and Yanliang District .0 .27