我国稻谷中硒元素空间分析

Analysis of the spatial pattern of selenium in rice in China

目的统计分析采样点稻谷中硒元素的含量,探索稻谷中硒含量的空间分布及聚集性。方法从全国18个省的163个地市592个区县的稻谷主要产区,采集2070份稻谷样品,采用描述性统计和空间自相关分析法对稻谷中硒元素分布及其相关性进行研究。结果抽样省份的稻谷中硒含量呈现右偏态分布,平均值为0.046 mg/kg,抽样省份的稻谷中硒含量的Moran’s I指数值为0.20,整体上具有低度的聚集性。局部空间自相关分析发现,其中海南省的万宁市呈现"低-高"聚集的现象,海南省的琼海市、东方市、屯昌县,辽宁省的盘锦市、营口市呈现出"高-高"聚集的现象。结论我国大部分地区种植的稻谷硒含量较低,局部地区稻谷中硒含量具有空间相关性和聚集性。

Objective To statistically analyze the selenium content in rice at sampling points, and explore the spatial distribution and aggregation of selenium content in rice. Methods A total of 2070 rice samples were collected from 592 districts and counties in 163 prefectures and cities in 18 provinces of China. The distribution and correlation of selenium in rice were studied by descriptive statistics and spatial autocorrelation analysis. Results The selenium content in rice from the sampled provinces showed a right-skewed distribution, with an average value of 0.046 mg/kg. The Moran’s I index value of the selenium content in the rice of the sampled provinces was 0.20, which showed a low degree of aggregation as a whole. According to the analysis of local spatial autocorrelation, Wanning city in Hainan province presented the phenomenon of "low-high" clustering, Qionghai city, Dongfang city and Tunchang county in Hainan province, and Panjin city and Yingkou city in Liaoning province presented the phenomenon of "high-high" clustering. Conclusion Selenium content in rice from most parts of China was low, while selenium content in rice from local areas presented spatial correlation and clustering.