摘要
利用1961～2007年逐日降水资料,分析了环渤海地区不同级别降水日数、降水量和降水强度的气候特征和变化趋势。结果表明:年及四季雨日均呈减少趋势,雨日的减少主要体现在微雨和小雨日数的显著减少;降水强度略有增加,但主要是源于微雨和小雨降水强度的增加;20世纪90年代以来,小雨和中雨雨量对年总降水量的贡献较大,极端强降水频率和降水量减少,其对年总降水量的贡献偏小,造成环渤海地区年降水量减少,气象干旱加重;雨日的减少使连续无降水事件频率加大,也在一定程度上加剧了干旱程度。
In line with the global climate change,the surface air temperature in the Bohai Rim area significantly increased for the 20th century.Accompanying the change of surface air temperature,heavy and very heavy precipitation has greatly changed,especially in recent years.Changes in patterns of extreme precipitation events and the possible mechanism for the changes have received more and more attention worldwide.The study aims to investigate the climatic characters and changing trend of rainfall days,rainfall amount and rainfall intensity in the Bohai Rim area by using daily precipitation data from 1961 to 2007.The results show that the number of annual and seasonal rainfall days（days with rainfall more than 0.1 mm） significantly decreases,and the decrease of rainfall days dominantly results from the significant decline in trace and light rainfall days,especially in autumn.In contrast,rainfall intensity shows a weak increase,mainly due to the increase in trace and light rainfall intensities.In comparison of the contribution of different categories of precipitation to annual total rainfall,it is found that there is a significant interannual variation in the contribution.Since the 1990s,annual rainfall has mainly come from light and moderate rainfall,whereas extreme heavy rainfall has contributed less to the annual rainfall due to the decrease in frequency and amount of extreme heavy rain.The results indicate that the decrease of trace and light rainfall days,which leads to the increase in frequency of events of continuous non-rain days,might have partly exacerbated the extent of drought in this area.However,the decline of annual rainfall as a result of the decrease of heavy rain or rainstorms,which is the dominant contribution to total rainfall,is the main factor for producing the severe meteorological drought after 1980.
出处
《地理研究》
CSCD
北大核心
2010年第12期2271-2280,共10页
Geographical Research
基金
国家“十一五”科技支撑计划课题(2007BAC03A01和2007BAC29B02)
全国流域综合规划修编研究专题
中国气象局气候变化专项(CCSF-09-01)
关键词
降水日数
降水强度
气候变化
环渤海地区
rainfall days
rainfall intensity
climate change
the Bohai Rim
