1958—2009年松花江流域降水时空演变特征

利用松花江流域降水资料,采用克里格(Kriging)法进行插值,用Mann-Kendall秩次相关法分析降水系列的变化趋势,用集中度和集中期分析降水量年内分配特征等,分析了流域降水特征时空变化。结果表明:①1958—2009年52 a来流域年降水呈不显著减少趋势,降水由东部向西部递减,绝大部分地区年降水呈不显著减少趋势;②年内降水不均匀,大多集中在5—9月,6—8月最为集中,汛期(6—9月)降水占全年77.65%,呈不显著减少趋势;③流域年降水集中度很大,多年均值为0.682,呈东南小西北大的特点。年降水集中期为181.90°~187.68°,最大降水一般出现在7月20—26日,集中期地域差异不大,总体呈北高南低的特点,年降水集中度减少趋势不显著,集中期呈显著减少趋势。

Temporal and Spatial Variation of Characteristics of Precipitation in Songhua River Basin during 1958-2009

In order to illustrate and analyze temporal and spatial variation of characteristics of precipitation in Songhua River Basin,the precipitation data were interpolated by Kriging interpolation method.The Mann-Kendall test was applied to examine the trend of precipitation.The concentration degree and period of annual precipitation were used to analyze the annual distribution of precipitation.The results show that ∶ 1) In recent 52 years(1958—2009) the annual precipitation shows an indistinctive negative trend.The annual precipitation decreases from eastern part to western part,and most of the basin area show an indistinctive negative trend.2) The annual precipitation distribution is uneven,occurs mainly from May to September,with June to August being most abundant.The flood-season(from June to September) precipitation occupies 77.65% of the annual precipitation and shows a weak negative trend throughout the basin.3) The concentration degree of annual precipitation is very high,averaging 0.682,and the concentration degree of southeastern part is smaller than that of northwestern part.The concentration period of annual precipitation is from 181.90° to 187.68°,the annual precipitation is concentrated from 20,July to 26,July,the concentration period of northern part is longer than that of southern part.The concentration degree of annual precipitation shows an indistinctive decreasing trend,while the concentration period of annual precipitation shows a significant decreasing trend.