1961―2015年中国不同强度降雨的变化趋势和波动特征

Tendency and Fluctuation of Different Rainfall Intensities in China during 1961-2015

采用1961―2015年中国535个降水站点数据,根据中国气象局颁布的降水强度等级划分标准,利用变化趋势和变异系数的方法,从降雨雨量和雨日特征2个方面对比研究了中国不同强度降水的空间格局。结果表明:1)1961―2015年中国不同强度降雨雨量和雨日变化趋势表现出不同的空间分异格局。其中小雨和中雨在东北、新疆北部、甘肃、青海和西藏地区以增加趋势为主,在西南和华南地区则以减少趋势为主。大雨在长江中下游以南地区以增加趋势为主,而西南地区以减少趋势为主。暴雨、大暴雨和总暴雨在东部和南部广大区域呈增加趋势,华北地区以减少趋势为主。特大暴雨仅在四川部分地区和东南沿海地区有增加趋势。2)1961―2015年中国不同强度降雨雨量和雨日呈现出不同程度的波动特征。小雨、中雨、大雨、暴雨、大暴雨和总降雨均在西北波动最大。特大暴雨波动最大的区域则主要分布在环渤海及其以南的广大地区。综上所述,中国的降雨在朝着极端化方向发展,提出适应、设防和减轻降水不利影响的应对方案势在必行。

Since climatic condition is the important foundation for human subsistence and development, and the key factor in sustainable development of economy and society, the long-term trend change of different intensity precipitation, as one of the climatic elements, has been a global issue attracting great attention of politicians, scientists, governments, and the public alike throughout the world. In this research 535 stations＇ meteorological data between 1961 and 2015 are from Daily Surface Meteorological Observation Data Sets of China provided by National Meteorological Information Center of China Meteorological Administration. According to the precipitation intensity grading standard issued by the China Meteorological Administration, rainfall events can be divided into six grades： light rainfall, moderate rainfall, heavy rainfall, storm rainfall, torrential rainfall and severe storm rainfall, in which the latter three grades constitute total storm rainfall, while all the six grades constitute total rainfall. Here starting from the annual rainfall amounts and rainfall days, we use tendency and fluctuation to diagnose different intensities＇ rainfall amounts and days. The results show that, the tendencies of different intensities＇ rainfall amounts and days show different spatial patterns. The light rainfall and moderate rainfall amounts are given priority to increasing trend in the northeast China, northern Xinjiang, Gansu, Qinghai and Tibet. In southwest and south China are given priority to decreasing trend. The heavy rainfall is given priority to increasing trend in the regions south of the middle and lower reaches of the Yangtze River, while decreasing trend in southwest China. And, storm rainfall, torrential rainfall and total storm rainfall show increasing trend in the east and south China with vast regions, while decreasing trend in north China. Extraordinary storm rainfall in parts of Sichuan and the southeast coastal regions have increasing trend, the increasing or decreasing trends in other parts of China are not obvious. The fluctuations of different intensities＇ rainfall amounts and days show different spatial patterns. Light rainfall, moderate rainfall, heavy rainfall, storm rainfall, torrential rainfall and total rainfall have higher fluctuations in the northwest than in other regions. Extraordinary storm rainfall with high fluctuation is mainly distributed in the Bohai Sea rim and the vast regions south of the sea. To sum up, China＇s rainfall is in development in the direction of extremalization. Putting forward some projects to response and reduce the adverse effect of precipitation extremalization is imperative.