摘要
[目的]探究嫩江流域降水及季节性降水变化特征。[方法]选取该流域内10个气象站,基于1969—2010年逐日降水数据,计算年降水量及冬夏季降水量,采用Mann-Kendall趋势检验法分析流域降水变化趋势,采用Theil-Sen estimator来计算趋势幅度,并利用Mann-Kendall突变检测法确定流域降水量发生突变的关键节点,综合分析嫩江流域降水的时间变化特征。[结果]近42年来嫩江流域年降水量以4.7 mm/10 a的幅度不显著下降,夏季降水量下降幅度(10.1 mm/10 a)高于年降水量,冬季降水量则表现为显著上升趋势,变化幅度为1.3 mm/10 a。嫩江流域年降水量为373.1~507.8 mm,夏季降水量为231.7~309.4 mm,冬季降水量为3.6~11.4 mm,中上游的降水量高于下游,10个站点年降水量主要以下降趋势为主,夏季降水量均表现为下降趋势,除乾安站降水量不显著下降外,其他站点冬季降水量均表现为上升趋势。夏季降水变化与年降水表现为较高的相似性,两者的Mann-Kendall突变检验结果也在形态上非常相近,均出现3个阶段的趋势变化,且波峰相近;在20世纪70年代前后为第1阶段,表现为减少趋势;80—90年代为第2阶段,表现为增加趋势;21世纪初期为第3阶段,再次表现为下降趋势。在0.05显著性水平上,年、夏季降水量在20世纪70年代前后和21世纪初期存在多个突变点,降水减少阶段变化较不稳定,增加阶段无交点存在。冬季与年、夏季结果差异较大,表现为在1973—1978和1980—1986年降水量下降,其他时间段降水量上升;1998年为0.05显著性水平上的交点。[结论]嫩江流域多年降水特征以夏季降水量占年降水量比重大,且经历了减少—增加—减少趋势变化,最终表现为减少趋势。冬季降水量在1998年出现突变节点,该年之后冬季降水量显著增加。夏季降水是洪涝隐患之一,但多年来,不断增长的冬季降水变化也要给予关注。
[Objective]To investigate the characteristics of precipitation and seasonal precipitation changes in the Nenjiang River Basin.[Method]Ten meteorological stations in the area were selected to calculate the annual precipitation and the winter and summer precipitation based on their daily precipitation data from 1969 to 2010.The trend of precipitation change and its range were analyzed and calculated by using the Mann-Kendall Test and the Theil-Sen estimator respectively,and the Mann-Kendall method in detecting climate mutation was adopted to determine the key nodes where sudden changes in rainfall occur in the basin,and comprehensively analyze the temporal variation characteristics of precipitation in Nenjiang River Basin.[Result]Over the past 42 years,the annual precipitation in the Nenjiang River Basin had decreased insignificantly by 4.7 mm/10 a.The summer precipitation had decreased more than the annual precipitation by 10.1 mm/10 a,while the winter precipitation had shown a significant upward trend than the annual precipitation by 1.3 mm/10 a.The annual precipitation in the region was 373.1-507.8 mm,with the summer and winter precipitation was 231.7-309.4 mm and 3.6-11.4 mm.Precipitation in the middle and upper reaches was higher than in the lower reaches.The annual precipitation at 10 stations was commonly decreasing,especially in summer.Except Qian’an station,where the precipitation does not decrease significantly,all other stations show an increasing trend of winter precipitation.The changes of summer precipitation and annual precipitation showed a high similarity.The results of the Mann-Kendall mutation test for both were also very similar in morphology,with both showing a 3-phase trend change and similar wave crests.It could be summarized as the first stage around the 1970s,which showed a decreasing trend;the second stage in the 1980s-1990s,showing an increasing trend;and the third stage in the early 21st century,which again showed a decreasing trend.At the 0.05 significance level,there were several abrupt change points in the annual and summer precipitation around the 1970s and the early 21st century,and the change in the decreasing phase of precipitation was more unstable,and no intersection point existed in the increasing phase.The difference between winter and annual and summer results was larger,featuring a decrease in precipitation around 1973-1978 and 1980-1986,and an increase in precipitation in other periods;1998 was the intersection point at 0.05 significance level.[Conclusion]The multi-year precipitation characteristics of the Nenjiang River Basin were featured with a large proportion of annual precipitation in summer,and it had experienced a decreasing-increasing-decreasing trend change,and finally showed a decreasing trend.The winter precipitation showed a sudden change node in 1998,and the winter precipitation increased significantly after that year.Summer precipitation was one of the flooding hazards,but the increasing winter precipitation changed over the years should also be given attention to.
作者
鹿之慧
王东升
王丹宁
潘帅
LU Zhi-hui;WANG Dong-sheng;WANG Dan-ning(College of Environmental Science and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000)
出处
《安徽农业科学》
CAS
2023年第1期204-207,246,共5页
Journal of Anhui Agricultural Sciences
