The present study aims to propose a method to search for the most appropriate evacuation routes that take calorie consumption required for evacuees to reach evacuation sites into consideration, by focusing on disaster...The present study aims to propose a method to search for the most appropriate evacuation routes that take calorie consumption required for evacuees to reach evacuation sites into consideration, by focusing on disasters caused by heavy rainfall, and using genetic algorithm (GA) and geographic information system (GIS). Specifically, GA was used to design and develop an evacuation route search algorithm and 4 parameters including the number of generations, mutation rate number of individuals and crossover rate were set by conducting sensitivity analyses. Additionally, GIS was also used to create road network data and contour data for digital maps and calculate the altitude of each crossover point. Based on these, the necessary calorie consumption to reach evacuation sites for each route was calculated, and that made it possible to derive the several evacuation routes with the small values unlike other methods. By using GA and GIS to suggest detailed evacuation routes, which take the necessary calories required to reach evacuation sites into consideration, it can be expected that the present study should contribute to the decision-making of evacuees. Additionally, as the method is based on public information, the method has high spatial and temporal repeatability. Because evacuation routes are proposed based on quantified data, the selected evacuation routes are quantitatively evaluated, and are an effective indicator for deciding on an evacuation route. Additionally, evacuation routes that accurately reflect current conditions can be derived by utilizing detailed information as data.展开更多
NCEP/NCAR reanalysis data were used to characterize stratospheric temperature and water-vapor anomalies before and after the freezing rain and snow disaster of South China in 2008,and the influence of stratospheric ci...NCEP/NCAR reanalysis data were used to characterize stratospheric temperature and water-vapor anomalies before and after the freezing rain and snow disaster of South China in 2008,and the influence of stratospheric circulation anomalies on the troposphere.Stratospheric temperature and water-vapor anomalies provided good leading indicators of this weather event.The period from December 1st 2007 to February 28th 2008 was divided into 18 pentads.During the 6th pentad,temperature decreased significantly at 10 hPa in the near-polar stratospheric region,and the decreasing trend strengthened and extended downward and southward to middle and lower latitudes.During the 14th-18th pentads,the temperature decrease reached its maximum and extended to 30°N.This coincided with the widespread freezing rain and snow event.By the end of January 2008,the temperature decrease ended in the near-polar stratospheric region,but continued in the mid-latitude area of the troposphere as the freezing rain and snow weather persisted.Similar to the temperature variations,positive anomalies of relative humidity in the stratospheric near-polar region also strengthened and extended downward and southward,coinciding with the freezing rain and snow event.Along with the significant relationship between the freezing rain and snow disaster and stratospheric circulation anomalies,the stratospheric polar vortex changed its shape in late December,intensifying and spreading downward from the top of the stratosphere and southward to the Asian continent,resulting in a deepening of the East Asian Trough and a strengthening of meridional circulation.Before the occurrence of the freezing rain and snow event,temperature and vapor increases in the stratosphere transferred downward to the troposphere,along with a stratospheric flow in the near-polar region southward to lower latitudes.展开更多
文摘The present study aims to propose a method to search for the most appropriate evacuation routes that take calorie consumption required for evacuees to reach evacuation sites into consideration, by focusing on disasters caused by heavy rainfall, and using genetic algorithm (GA) and geographic information system (GIS). Specifically, GA was used to design and develop an evacuation route search algorithm and 4 parameters including the number of generations, mutation rate number of individuals and crossover rate were set by conducting sensitivity analyses. Additionally, GIS was also used to create road network data and contour data for digital maps and calculate the altitude of each crossover point. Based on these, the necessary calorie consumption to reach evacuation sites for each route was calculated, and that made it possible to derive the several evacuation routes with the small values unlike other methods. By using GA and GIS to suggest detailed evacuation routes, which take the necessary calories required to reach evacuation sites into consideration, it can be expected that the present study should contribute to the decision-making of evacuees. Additionally, as the method is based on public information, the method has high spatial and temporal repeatability. Because evacuation routes are proposed based on quantified data, the selected evacuation routes are quantitatively evaluated, and are an effective indicator for deciding on an evacuation route. Additionally, evacuation routes that accurately reflect current conditions can be derived by utilizing detailed information as data.
基金supported by National Natural Science Foundation of China(Grant Nos.41005021,40830955)Scientific Research Foundation of CUIT(Grant No.CSRF20102)Special Fund for Public Welfare Industry(meteorology)(Grant No.GYHY(QX)2007-6-37)
文摘NCEP/NCAR reanalysis data were used to characterize stratospheric temperature and water-vapor anomalies before and after the freezing rain and snow disaster of South China in 2008,and the influence of stratospheric circulation anomalies on the troposphere.Stratospheric temperature and water-vapor anomalies provided good leading indicators of this weather event.The period from December 1st 2007 to February 28th 2008 was divided into 18 pentads.During the 6th pentad,temperature decreased significantly at 10 hPa in the near-polar stratospheric region,and the decreasing trend strengthened and extended downward and southward to middle and lower latitudes.During the 14th-18th pentads,the temperature decrease reached its maximum and extended to 30°N.This coincided with the widespread freezing rain and snow event.By the end of January 2008,the temperature decrease ended in the near-polar stratospheric region,but continued in the mid-latitude area of the troposphere as the freezing rain and snow weather persisted.Similar to the temperature variations,positive anomalies of relative humidity in the stratospheric near-polar region also strengthened and extended downward and southward,coinciding with the freezing rain and snow event.Along with the significant relationship between the freezing rain and snow disaster and stratospheric circulation anomalies,the stratospheric polar vortex changed its shape in late December,intensifying and spreading downward from the top of the stratosphere and southward to the Asian continent,resulting in a deepening of the East Asian Trough and a strengthening of meridional circulation.Before the occurrence of the freezing rain and snow event,temperature and vapor increases in the stratosphere transferred downward to the troposphere,along with a stratospheric flow in the near-polar region southward to lower latitudes.
