Collaborative Innovation Center of South China Sea Studies, Nanjing University, Nanjing 210093, China; Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China; Geographic and Oceangraphic Sciences, Nanjing University, Nanjing 210023, China.
Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University, Nanjing 210023, China; Geographic and Oceangraphic Sciences, Nanjing University, Nanjing 210023, China.
Sci Total Environ. 2018 Apr 1;619-620:28-41. doi: 10.1016/j.scitotenv.2017.10.339. Epub 2017 Nov 11.
Understanding rainfall trends as well as drought characteristics plays a key role in watershed development and management. In this study, the spatial and temporal characteristics of rainfall and drought based on temperature and precipitation data observed in 48 meteorological stations from 1959 to 2012 across the Pearl River Basin in China were analyzed. The possible influence of El Nino-Southern Oscillation (ENSO) and El Nino Modoki (ENSO_M) events on seasonal drought based on the Standardized Precipitation-evapotranspiration Index (SPEI) were also investigated. The results show that annual and seasonal rainfall decreased slightly in most areas, annual and seasonal daily precipitation concentration decreased in a few areas, monthly rainfall had an irregular distribution but with no significant trend detected, and rainfall seasonality increased in most areas. Drought tended to worsen during recent years, especially in the upper reaches, and seasonal drought also tended to become serious or occurred frequently across the Pearl River Basin. The drought patterns are not only related to the decreasing trends in rainfall but also to changes in the daily rainfall concentration, monthly rainfall heterogeneity, and rainfall seasonality. Both ENSO and ENSO_M events had an influence on summer drought in the middle-upper reaches. The ENSO events dominated the patterns of autumn drought in the Pearl River Delta, and the ENSO_M events strongly affected the changing patterns of autumn drought in the middle-upper reaches and northern parts of the middle-lower reaches.
了解降雨趋势和干旱特征在流域开发和管理中起着关键作用。本研究基于 1959 年至 2012 年期间中国珠江流域 48 个气象站观测到的温度和降水数据，分析了降雨和干旱的时空特征。还根据标准化降水蒸散指数（SPEI）探讨了厄尔尼诺-南方涛动（ENSO）和厄尔尼诺模态（ENSO_M）事件对季节性干旱的可能影响。结果表明，大多数地区的年降雨量和季降雨量略有减少，少数地区的年和季日降雨量集中程度降低，月降雨量分布不规则，但未检测到明显趋势，大多数地区的降雨季节性增强。近年来干旱趋于恶化，特别是在上游地区，珠江流域的季节性干旱也趋于严重或频繁发生。干旱模式不仅与降雨量减少趋势有关，还与日降雨量集中程度、月降雨量异质性和降雨季节性变化有关。ENSO 和 ENSO_M 事件均对珠江流域中上流域夏季干旱有影响。ENSO 事件主导了珠江三角洲秋季干旱的模式，而 ENSO_M 事件强烈影响了中上流域和中下流域北部秋季干旱变化的模式。
