In order to improve the effectiveness of Fuzzy Synthetic Evaluation (FSE) models, a Parameter Correlation Analysis (PCA) was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang ...In order to improve the effectiveness of Fuzzy Synthetic Evaluation (FSE) models, a Parameter Correlation Analysis (PCA) was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang Plain, Northeast China. The basic principle of the PCA is that the pairs of parameters which are highly correlated and linear with each other would contribute the same information to an assessment and one of them should be eliminated. The method of the PCA is that a correlation relationship among candidate parameters is examined before the FSE. If there is an apparent nonlinear or curvilinear relationship between two parameters, then both will be retained; if the correlation is significant (p<0.01), and the scatter plot suggests a linear relationship, then one of them will be deleted. However, which one will be deleted? For solving this problem, a sensitivity test was conducted and the higher sensitivity parameters remained. The results indicate that the original data should be preprocessed through the PCA for redundancy and variability. The study shows that introducing the PCA into the FSE can simplify the FSE calculation process greatly, while the results have not been changed much.展开更多
This paper deals with a mortality-weighted synthetic evaluation (MWSE) method for evaluating urban air risk. Sulphur dioxide (SO2), nitrogen oxide (NOx), and particulate matter (PM10) were used as pollution indices. T...This paper deals with a mortality-weighted synthetic evaluation (MWSE) method for evaluating urban air risk. Sulphur dioxide (SO2), nitrogen oxide (NOx), and particulate matter (PM10) were used as pollution indices. The urban area of Hangzhou, China is divided into 756 grid cells, with a resolution of 1 km×1 km, and is evaluated using the MWSE and the air quality index (AQI), a widely-used method to evaluate ambient air quality and air risk. In an evaluation of one day in April 2004, the surface areas categorized as levels I and III, as defined by the integrated air risk evaluation, were 27.3% and 3.3% lower, respectively, than grades I and III defined by the AQI evaluation. Meanwhile, the areas classified as level II or above level III by the integrated air risk evaluation were 55.1% and 101.1% higher, respectively, than grade II or above grade III when using the AQI evaluation. From this comparison, we find that the MWSE method is more sensitive than the AQI method. The AQI method uses a single index to assess integrated air quality and is therefore unable to evaluate integrated air risks due to multiple pollutants. The MWSE method overcomes this problem, providing improved accuracy in air risk assessment.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40830535)Knowledge Innovation Pro-gram of Chinese Academy of Sciences (No.KSCX2-YW-N-46-06)
文摘In order to improve the effectiveness of Fuzzy Synthetic Evaluation (FSE) models, a Parameter Correlation Analysis (PCA) was introduced into the FSE and a case study was carried out in the Naoli River in the Sanjiang Plain, Northeast China. The basic principle of the PCA is that the pairs of parameters which are highly correlated and linear with each other would contribute the same information to an assessment and one of them should be eliminated. The method of the PCA is that a correlation relationship among candidate parameters is examined before the FSE. If there is an apparent nonlinear or curvilinear relationship between two parameters, then both will be retained; if the correlation is significant (p<0.01), and the scatter plot suggests a linear relationship, then one of them will be deleted. However, which one will be deleted? For solving this problem, a sensitivity test was conducted and the higher sensitivity parameters remained. The results indicate that the original data should be preprocessed through the PCA for redundancy and variability. The study shows that introducing the PCA into the FSE can simplify the FSE calculation process greatly, while the results have not been changed much.
基金Project(No. 200809103) supported by the State Environmental Protection Commonweal Trade Scientific Research, Ministry of Environmental Protection of China
文摘This paper deals with a mortality-weighted synthetic evaluation (MWSE) method for evaluating urban air risk. Sulphur dioxide (SO2), nitrogen oxide (NOx), and particulate matter (PM10) were used as pollution indices. The urban area of Hangzhou, China is divided into 756 grid cells, with a resolution of 1 km×1 km, and is evaluated using the MWSE and the air quality index (AQI), a widely-used method to evaluate ambient air quality and air risk. In an evaluation of one day in April 2004, the surface areas categorized as levels I and III, as defined by the integrated air risk evaluation, were 27.3% and 3.3% lower, respectively, than grades I and III defined by the AQI evaluation. Meanwhile, the areas classified as level II or above level III by the integrated air risk evaluation were 55.1% and 101.1% higher, respectively, than grade II or above grade III when using the AQI evaluation. From this comparison, we find that the MWSE method is more sensitive than the AQI method. The AQI method uses a single index to assess integrated air quality and is therefore unable to evaluate integrated air risks due to multiple pollutants. The MWSE method overcomes this problem, providing improved accuracy in air risk assessment.
