马尔康市1954—2019年降水与旱涝灾害变化

Variations in Precipitation Characteristics and Drought and Flood Disasters in Maerkang City from 1954 to 2019

利用马尔康市1954—2019年逐月气温、降水量实测资料,基于气候倾向率、突变检验、信噪比检验、周期估算等方法对本区气候变化、旱涝灾害演变特征进行分析,并借助ADF检验、Granger因果关系分析来验证旱涝灾害的驱动因子。结果显示:马尔康市年均气温、年降水量均呈显著上升趋势,气候有暖湿化倾向;多年平均降水量以16.29 mm/(10 a)的速率增加,以夏季、秋季增多明显,春季增幅最小;2001年为本区气候突变点,气温突变后的旱涝灾害呈增多态势,极端洪涝事件更为频繁,2015—2019年是一次重大洪涝事件;太阳黑子活动与ENSO事件皆为降水量变化的Granger原因。厄尔尼诺与南方涛动事件(ENSO)事件与马尔康地区的旱涝灾害在6.6 a上有较同步的共振周期,滞后期为2 a的ENSO事件是旱涝变化的主要诱因之一。ENSO事件在年尺度上为区域旱涝预警提供了重要理论支撑。

The characteristics of climate change and evolution of drought and flood disasters in Maerkang City were examined through tests of climate tendency rate,abrupt change,signal-to-noise ratio,and cycle estimation based on the measured data of monthly temperature and precipitation from 1954 to 2019.The driving factors of drought and flood disasters were verified via ADF test and Granger causality analysis.The average annual temperature and annual precipitation showed a significant upward trend,and the climate tended to be warm and humid.The average annual precipitation increased at a rate of 16.29 mm/10a,obvious in summer and autumn while to the minimum in spring.Climate changed abruptly in 2001,after which the drought and flood disasters increased and the extreme flood events became more frequent.The years from 2015 to 2019 witnessed a large flood event.Both sunspot activity and ENSO(El Nino-Southern Oscillation)events are Granger causes of precipitation variation.The ENSO events and the drought and flood disasters have synchronous resonance period in 6.6 years.The ENSO event with a lag period of two years is one of the main causes of the changes in drought and flood disasters.ENSO events provide an important theoretical support for regional drought and flood warning on an annual scale.