In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent ...In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent criteria in the ecological impact assessment of highways,and to scientifically screen assessment indicators,the paper proposes a multi-round indicator screening method,which combines literature analysis,expert rating,and statistical analysis.Based on this screening method,normalized difference vegetation index,land surface temperature,elevation,and normalized difference soil index are screened out.Combined with multiple linear regression,an ecological impact assessment model is established and applied to ecological impact assessment of Gonghe-Yushu Expressway.The results show that the expressway construction is the first driving force for the deterioration of the ecological environment along the roadside,and its interference range on the desert grassland ecosystem is greater than that on the agroforestry system.The ecological environment within 150 m on both sides of the expressway should be protected.展开更多
Based on the ETM remote sensing images of Guangzhou City in 2014, the spatial distribution results o f three environmental factors including vegetation coverage(NDVI), soil index(vegetation index of bare soil) and sl ...Based on the ETM remote sensing images of Guangzhou City in 2014, the spatial distribution results o f three environmental factors including vegetation coverage(NDVI), soil index(vegetation index of bare soil) and sl ope were obtained. By using comprehensive index method, the normalized environmental factors were weighted and superimposed, and the fi nal evaluation results of ecological environment in Guangzhou City were obtained. The results showed that overall situation of natural ecological environment in Guangzhou was not optimistic, that is, the area of land with bad, moderate, good and superior environment accounted for 59.70%, 35.79%, 4.50% and around 0.01% of total area of land in Guangzhou City respectively. Ecological environment was generally poor in the central urban districts in the south of Guangzhou City, while it was relatively better in the north and northeast. Attaching importance to the constr uction of greenbelts and greenways is an effective way to improve regional environmental quality and natural ecological e nvironment level.展开更多
[Objective] To analyze and compare the heavy metal inspection results of different livestock and poultry meat from different farms,wholesale markets,farmers' markets and supermarkets in different areas of China,in...[Objective] To analyze and compare the heavy metal inspection results of different livestock and poultry meat from different farms,wholesale markets,farmers' markets and supermarkets in different areas of China,in order to evaluate the health risks of livestock and poultry meat.[Method] A total of 10 500 samples of 5 kinds of livestock and poultry meat were collected in North China,Northeast China,East China,Central China,South China,Southwest China and Northwest China during 2015-2017.The samples were analyzed and evaluated with the method of index of food safety( IFS).[Result]the average over-standard rates of Pb,Cd,Cr,Hg and As in samples were 1.10%-2.48%,0.67%-2.48%,1.00%-2.57%,0.81%-1.43% and 0.43%-1.00%,respectively,and the index of food safety was less than 1.The pollution levels of Pb,Cd,Cr,Hg and As in livestock and poultry meat in Southwest China were higher than those in other areas,while the pollution of As in Northeast China was severer than that in other areas.The order of IFS values of different heavy metals in different livestock and poultry meat was the same.[Conclusion] The index of food safety showed that the risk of heavy metal pollution in livestock and poultry meat did not exceed the acceptable limit.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(No.41801387)。
文摘In recent years,the ecological environment along highways in Tibetan Plateau has been severely affected due to the rapid construction of highways.In order to solve the problems of multiple indicators and inconsistent criteria in the ecological impact assessment of highways,and to scientifically screen assessment indicators,the paper proposes a multi-round indicator screening method,which combines literature analysis,expert rating,and statistical analysis.Based on this screening method,normalized difference vegetation index,land surface temperature,elevation,and normalized difference soil index are screened out.Combined with multiple linear regression,an ecological impact assessment model is established and applied to ecological impact assessment of Gonghe-Yushu Expressway.The results show that the expressway construction is the first driving force for the deterioration of the ecological environment along the roadside,and its interference range on the desert grassland ecosystem is greater than that on the agroforestry system.The ecological environment within 150 m on both sides of the expressway should be protected.
基金Sponsored by National Natural Science Foundation of China(41271060)
文摘Based on the ETM remote sensing images of Guangzhou City in 2014, the spatial distribution results o f three environmental factors including vegetation coverage(NDVI), soil index(vegetation index of bare soil) and sl ope were obtained. By using comprehensive index method, the normalized environmental factors were weighted and superimposed, and the fi nal evaluation results of ecological environment in Guangzhou City were obtained. The results showed that overall situation of natural ecological environment in Guangzhou was not optimistic, that is, the area of land with bad, moderate, good and superior environment accounted for 59.70%, 35.79%, 4.50% and around 0.01% of total area of land in Guangzhou City respectively. Ecological environment was generally poor in the central urban districts in the south of Guangzhou City, while it was relatively better in the north and northeast. Attaching importance to the constr uction of greenbelts and greenways is an effective way to improve regional environmental quality and natural ecological e nvironment level.
基金Supported by National Key Research and Development Program of China(2017YFC1601800)
文摘[Objective] To analyze and compare the heavy metal inspection results of different livestock and poultry meat from different farms,wholesale markets,farmers' markets and supermarkets in different areas of China,in order to evaluate the health risks of livestock and poultry meat.[Method] A total of 10 500 samples of 5 kinds of livestock and poultry meat were collected in North China,Northeast China,East China,Central China,South China,Southwest China and Northwest China during 2015-2017.The samples were analyzed and evaluated with the method of index of food safety( IFS).[Result]the average over-standard rates of Pb,Cd,Cr,Hg and As in samples were 1.10%-2.48%,0.67%-2.48%,1.00%-2.57%,0.81%-1.43% and 0.43%-1.00%,respectively,and the index of food safety was less than 1.The pollution levels of Pb,Cd,Cr,Hg and As in livestock and poultry meat in Southwest China were higher than those in other areas,while the pollution of As in Northeast China was severer than that in other areas.The order of IFS values of different heavy metals in different livestock and poultry meat was the same.[Conclusion] The index of food safety showed that the risk of heavy metal pollution in livestock and poultry meat did not exceed the acceptable limit.
