Gaoyuan qixiang (Dec 2023)
Analysis of Flood Season Precipitation and Extreme Precipitation in Gansu Province Based on Data from Different Types of Meteorological Stations
Abstract
In this paper， the data quality control of the flood season precipitation and extreme precipitation of the regional meteorological stations and national meteorological stations in Gansu Province from 2011 to 2020 has been carried out， and 1253 regional meteorological stations and 75 national meteorological stations have been selected to analysis the precipitation characteristics.The results show that the average precipitation amount of the regional meteorological stations in Gansu Province is very close to that of the national meteorological stations， and there is no significant difference.The average precipitation of the regional meteorological stations in flood season in Gansu province is 382.9 mm， and that of the national meteorological stations is 379.7 mm.The average monthly precipitation of regional meteorological stations distributes from 31.7 mm to 87.1 mm， and that of national meteorological stations distributes from 30.4 mm to 86.4 mm.However， there are significant differences in the extremes of precipitation between the two types of meteorological stations.The maximum of total precipitation at regional meteorological stations in flood season even reaches 917.5 mm， the maximum monthly precipitation reaches 776 mm， and the maximum number of rainstorm days reaches 46 d·（10a）-1.However， those of national meteorological stations is 710.7 mm， 541 mm and 17 d·（10a）-1， respectively.The spatial locations of precipitation maxima of regional meteorological stations and national meteorological stations are close to each other， but the numerical values of regional stations are significantly higher than those of national stations.The spatial trends of precipitation at the two stations are very consistent， and the correlation coefficient of flood season precipitation of two types stations is 0.95， the correlation coefficient of monthly extreme precipitation is 0.92.Moreover， regional meteorological stations show many higher and less value centers of small patches than national stations； the spatial precipitation difference between the two types of meteorological stations are clearly in the east and south of Gansu Province.Overall， the regional meteorological stations describe the precipitation characteristics of Gansu Province in a more detailed way.More extreme precipitation events are monitored in those regions with complex terrain， and the extreme value of precipitation is larger than that of national meteorological stations.The rainstorm and flood disaster prevention in these regions should be based on the data of regional meteorological stations to enhance the disaster risk prevention ability.
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