徒骇河-马颊河流域极端降水事件时空演变及未来趋势分析

Spatiotemporal evolution and future trend analysis of extreme precipitation events in Tuhai-Majia River Basin

摘要

【目的】为研究徒骇河-马颊河流域极端降水事件历史及未来时空变化特征，以期为预防未来可能发生的气候灾害提供理论参考。【方法】基于徒骇河-马颊河流域的26个国家气象站1967—2021年55 a间的日降水资料，借助RClimDex1.1模型计算8个极端降水指数，利用Mann-Kendall检验法、ANUSPLIN空间插值法、小波变换等方法对徒骇河-马颊河流域极端降水指数变化进行研究，并采用NEX-GDDP-CMIP6数据集预测该流域未来气候变化趋势。【结果】结果表明：(1)1967—2021年，徒骇河-马颊河流域除连续干旱日数(CDD)和连续湿润日数(CWD)呈下降趋势外，其余指数均呈增加趋势。研究区内1 d最大降水量(Rx1day)、极强降水总量(R99P)、CWD、CDD在研究期内发生明显突变。其余指数突变不明显。各极端降水指数在研究期内呈现明显的周期性变化，显著变化主周期多介于2~4.8 a。(2)研究区极端降水指数具有明显空间差异，部分极端降水指数与地形因素具有显著的相关性，年降水量(PRCPTOT)、极端降水总量(R95P)、R99P高值在流域南部，而Rx1day与5 d最大降水量(Rx5day)高值集中在流域北部。(3)徒骇河-马颊河流域在2015—2100年不同排放情景(SSP1-2.6、SSP2-4.5、SSP5-8.5)下，流域内极端降水事件整体呈现增加趋势。(4)极端降水指数与气候指数的交叉小波变换具有不同功率，其中降水指数与太阳黑子数(SN)的交叉小波变换的功率最大，振荡凝聚性最强，多呈现负相关性。【结论】总体而言，各项降水指数的变化显示该区域逐渐变得更加湿润，徒骇河马颊河流域极端降水南北差异显著，未来应针对性优化流域南、北部的差异化防灾体系，加强对流域极端降水事件的监测预警和应对能力建设，减少流域灾害风险。

Abstract

[Objective] To investigate the historical and future spatiotemporal variation characteristics of extreme precipitation events in the Tuhai-Majia River Basin, aiming to provide theoretical references for preventing potential future climate disasters. [Methods] Based on daily precipitation data from 26 national meteorological stations in the Tuhai-Majia River Basin over a 55-year period from 1967 to 2021, eight extreme precipitation indices were calculated using the RClimDex1.1 model. The Mann-Kendall(M-K) test, ANUSPLIN spatial interpolation, and wavelet transform were applied to analyze the changes in extreme precipitation indices. The NEX-GDDP-CMIP6 dataset was used to predict future climate change trends in the river basin. [Results] The result showed that:(1) from 1967 to 2021, all indices in the Tuhai-Majia River Basin showed increasing trends, except for consecutive dry days(CDD) and consecutive wet days(CWD), which showed decreasing trends. Significant abrupt changes were observed in maximum 1-day precipitation(Rx1day), very extreme precipitation(R99P), CWD, and CDD during the study period. Other indices showed no significant abrupt changes. All extreme precipitation indices exhibited notable periodic variations during the study period, with major cycles generally ranging from 2 to 4.8 years.(2) The extreme precipitation indices in the study area showed significant spatial variation. Some indices were strongly correlated with topographic factors. Total annual precipitation(PRCPTOT), total extreme precipitation(R95P), and R99P showed higher values in the southern part of the river basin, while Rx1day and maximum 5-day precipitation(Rx5day) had higher values concentrated in the northern part of the river basin.(3) Under different emission scenarios(SSP1-2.6, SSP2-4.5, SSP5-8.5) from 2015 to 2100, extreme precipitation events in the river basin were projected to generally show an increasing trend.(4) The cross-wavelet transform between extreme precipitation indices and climate indices showed different power levels. Among them, the cross-wavelet power between extreme precipitation indices and sunspot number(SN) was the strongest, showing high oscillation coherence and mostly negative correlation. [Conclusion] Overall, the variations in precipitation indices indicate that the region is becoming increasingly humid. There are significant north-south differences in extreme precipitation in the Tuhai-Majia River Basin. Future efforts should focus on optimizing differentiated disaster prevention systems in the northern and southern parts of the river basin and enhancing the monitoring, early warning, and response capabilities for extreme precipitation events to reduce disaster risks within the river basin.

关键词

极端降水指数 / 时空变化 / 徒骇河-马颊河流域 / NEX-GDDP-CMIP6 / ANUSPLIN插值 / 气候变化 / 厄尔尼诺-南方涛动 / 影响因素

Key words

extreme precipitation index / spatiotemporal variation / Tuhai-Majia River Basin / NEX-GDDP-CMIP6 / ANUSPLIN interpolation / climate change / ENSO / influencing factors

基金资助

国家自然科学基金项目(42007153)

山东省自然科学基金项目(ZR2021ME145)

济南大学2023 年学科交叉会聚建设项目(XKJC-202305)