1960—2015年呼伦贝尔草原气温和降水格局变化特征

VARIATIONS OF TEMPERATURE AND PRECIPITTION PATTERN IN HULUNBER GRASSLAND FROM 1960 TO 2015

关键词:  呼伦贝尔气温变化降水格局Mann Kendall趋势分析Sen′s斜率估计

Key words:  Hulunber  temperature variation  precipitation pattern  Mann Kendall non parametric test  Sen′s non parametric estimation

摘要:

［目的］利用1960—2015年呼伦贝尔草原区逐日气象数据，分析了该地区这56年来气温和降水的分布与变化规律。［方法］文章采用Mann Kendall非参数趋势检验和Sen′s斜率估计分析了温度、降水变化的趋势和变化速度。［结果］(1）呼伦贝尔草原区过去56年中气温呈现出极显著波动增加的趋势，其中第二季度增温的趋势最明显，年均温增加中值005℃。海拉尔区增温速度为草原区最快，年增加中值004℃。(2）呼伦贝尔草原区这56年中降水呈现出不显著的波动下降趋势，年降水减少中值041mm。其中第三季度降水量显著减少，年降水减少中值092mm，第一、四季度降水量显著增加，年降水增加中值007～023mm。第二季度变化较小。满洲里市降水量极显著下降，下降速度为草原区最高，年降水减少中值125mm。(3）1～5mm降水次数和总降水贡献呈显著增加趋势，年增加中值0102%， 5～30mm降水次数和降水贡献呈现减少趋势，单次降水30mm以上频率很低。(4）历时1～2d的降水是研究区最主要的连续降水类型，独立单日降水呈现不显著增加趋势， 2～3d连续降水呈现不显著减少趋势，连续4d和4d以上降水事件较为罕见。［结论］呼伦贝尔草原区过去56年整体看呈现出暖干化的趋势，年内尺度看降水呈现均匀化趋势，第三季度减少，第一、四季度增加。降水格局表现为分散化趋势，极端降水事件减少，小雨增加； 连续降水减少，单日独立降水增加。

Abstract:

By using daily meteorological data of Hulunber grassland from 1960 to 2015，this study analyzed the characteristics of spatial and temporal distribution and variation of temperature and precipitation pattern in 56 years. Mann Kendall non parametric test and Sen′s non parametric estimation were applied to analyze temperature and precipitation variation trend and rate. The results show that ( 1) Temperature increase significantly in Hulunber grassland in the past 56 years, quarter 2nd has the most significance with annual increasement of 0.05℃, Hailar district has the most increase speed with annual increasement of 0.04℃. (2) Precipitation reduction is not significant, however, quarter 3rd shows significant reducing with annual decrease of 0.92mm and quarter 1st and 4th shows significant growing with annual increasement of 0.07～0.23mm. Precipitation reduction is very significant in Manchuria and it has the most reducing speed with annual decrease of 1.25mm in Hulunber. ( 3) 1～5mm precipitation frequency and precipitation contribution show significant increase trend, with annual increasement of 0.102%, 5～30mm precipitation frequency and precipitation contribution show some reducing trend with no significance. Only few days have precipitation over 30mm in Hulunber grassland. (4) Precipitation lasting 1～2 day is the main raining type, 1 day precipitation shows growth trend and 2～3 day precipitation shows reduce trend. Precipitation lasting or over 4 days are very rare in Hulunber grassland. In the past 56 years, Hulunber grassland has showed warming and drying trend, in quarter scale precipitation has tended to homogenization Quarter 3rd precipitation has reduced and quarter 1st and 4th precipitation has increased. Precipitation tend to decentralization extreme rain invents reduces and small rainfall increase, long term rain invents reduces and one day rainfall increase.