关键词: 蔬菜, 蔬菜, 农药残留, 文献计量

Abstract: To study the spatial-temporal characteristics and driving factors and provide reasonable suggestions on intensive land use for 16 cities in the Yangtze River Delta Region, the improved entropy method was used to evaluate the intensive land use level from 2007 to 2013. Spearman rank correlation coefficient and coefficient of variation were used to analyze the temporal characteristics, and spatial autocorrelation analysis was used to analyze the spatial characteristics. The results showed that the development of intensive land use level was slow from 2007 to 2008 and then kept rising rapidly from 2009 to 2013. Intensive land use level increased rapidly in Shanghai, Nanjing and Hangzhou from 2007 to 2013 and increased only in small steps in Wuxi and Suzhou, while decreased slowly in Nantong. And the difference of intensive land use among cities during this period was becoming smaller. Cities with mid-high level of intensive land use presented a half-circle spatial distribution, and cities with the low level presented a belt distribution. Besides, the cities with high level of intensive land use always became hot spots in space and the cities with low level became cold spots, but the spatial correlation of intensive land use among the 16 cities was not obvious. Last but not least, driving factors including geographical location, economic development level and land marketization level had significant influence on the level of intensive land use. Thus, specific measures with consideration to local conditions should be taken to push intensive land use to a higher level. And it is of great significance for central cities to provide trickle-down effect for surrounding cities.