A new assessment in total and extreme rainfall trends over central and southern Peruvian Andes during 1965-2010
A new assessment in total and extreme rainfall trends over central and southern Peruvian Andes during 1965-2010
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DOI：
10.1002/joc.5427
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发表时间：
2018-04-01
期刊：
影响因子：
--
通讯作者：
Quiroz, Roberto
中科院分区：
文献类型：
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作者：
Heidinger, Haline;Carvalho, Leila;Quiroz, Roberto
了解安第斯山脉等山区降雨量的时空变异性对于维护水资源和生态系统至关重要。本研究全面分析了1965-2010年秘鲁安第斯山脉中部和南部(CSPA)降雨趋势的信号、统计意义和空间格局。使用水文历年对47个质量控制雨量站的降雨量进行了检查。计算了气候变化检测和指数专家组(ETCCDI)提出的总降雨量和极端降雨量指数，并用Mann-Kendall检验和Sen‘s斜率估计器检验了趋势。调查了极端降雨量变化的显著区域模式，并与以前的研究进行了比较。根据主成分分析和聚类技术，确定了四个主要的站点区域：亚马逊、中太平洋、南太平洋和喀喀湖盆地。统计上显著的趋势模式表明，亚马逊盆地的年总降雨量有所减少，尽管降雨天数和一些极端降雨指数有所增加。在中太平洋观察到1天和5天的年最大降雨量减少，而潮湿天数增加。在南太平洋发现了与每日极强降雨强度有关的指数的积极趋势。Titicaca盆地的极端降雨强度有所增加。对厄尔尼诺-南方涛动(ENSO)和太平洋年代际涛动(PDO)的降水变率和趋势进行了对比分析。在拉尼娜(El Nino)年，CSPA的大多数站都表现出总降水指数和极端降水指数(连续干旱日)的正(负)距平。亚马逊、南太平洋和喀喀山盆地分别出现了年总降雨量的正(负)异常和PDO正(负)的连续干旱日数。ENSO-PDO条件可能影响了CSPA复杂且大多没有统计意义的长期趋势。
Understanding the spatio-temporal variability of rainfall over mountainous regions such as the Andes is crucial for the maintenance of water resources and ecosystems. This study provided a comprehensive analysis of the signal, statistical significance and spatial pattern of rainfall trends in central and southern Peruvian Andes (CSPA) from 1965 to 2010. Rainfall from 47 quality-controlled rain gauge stations was examined using the hydrologic calendar year. Total and extreme rainfall indices proposed by the Expert Team on Climate Change Detection and Indices (ETCCDI) were calculated and trends were examined with Mann-Kendall test and Sen's slope estimator. Significant regional patterns of changes in rainfall extremes were investigated and compared with previous studies. Four major regions of stations were identified based on principal component analysis and clustering techniques: Amazon, central Pacific, southern Pacific and Titicaca basins. Statistically significant trend patterns showed that the annual total rainfall has decreased in the Amazon basin, despite the increase in the number of rainy days and some extreme rainfall indices. Decrease in 1-day and 5-day yearly maximum rainfall was observed in central Pacific, along with an increase in the number of wet days. Positive trends in indices related to the intensity of very strong daily rainfall were detected in southern Pacific. Titicaca basin showed an increase in the intensity of rainfall extremes. Rainfall variability and trends were evaluated during contrasting El Nino-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). Most stations in the CSPA exhibited positive (negative) anomaly of total and extreme rainfall indices (consecutive dry days) during La Nina (El Nino) years. Positive (negative) anomalies of annual total rainfall and consecutive dry days during positive (negative) PDO occurred in the Amazon, southern Pacific and Titicaca basins, respectively. The ENSO-PDO conditions may have influenced the complex and mostly non-statistically significant long-term trends in CSPA.