Department of Geography, University of Gujrat, Gujrat, Pakistan.
Department of Geography, University of Peshawar, Peshawar, Pakistan.
PLoS One. 2021 Apr 15;16(4):e0249718. doi: 10.1371/journal.pone.0249718. eCollection 2021.
This study analysed spatio-temporal fluctuations in rainfall to assess drought and wet spells in Khyber Pakhtunkhwa, Pakistan. Temporal changes in rainfall were assessed using a linear regression method, while aridity conditions at each meteorological station were measured using the United Nations Environment Programme climate aridity index. In this study, drought and wet spell patterns were identified using the Standardized Precipitation Evapotranspiration Index (SPEI). The Spearman's Rho (SR) test was applied to find trends in the temporal 1-month and 12-month SPEI data. Balakot, Dir, Kakul, Kalam, Malam Jabba, Parachinar, Patan and Saidu were humid whereas Cherat and Timergara were sub-humid meteorological stations while Bannu, Chitral, Drosh and Peshawar were semi-arid and D.I. Khan was found to be the only arid meteorological station in the study area. The regression results revealed that the amount of rainfall is decreasing at Balakot, Kakul and Dir, while in the southern part of the province the amount of rainfall is increasing, such as in Parachinar and Cherat. The SPEI results revealed distinct drought spells in 1971-1974, 1984-1989, 1998-2004 and recently in 2017-2018, in almost all met-stations results. The SR results indicated a significant wet trend at met-station Parachinar, located in the west, while a significant drying trend has been noted at Balakot in the north-eastern part of the study area. Detailed knowledge about rainfall variability can provide a foundation for the planning and use of water resources.
本研究分析了降雨的时空波动，以评估巴基斯坦开伯尔-普赫图赫瓦省的干旱和湿润期。使用线性回归方法评估降雨的时间变化，同时使用联合国环境规划署气候干旱指数测量每个气象站的干旱条件。在本研究中，使用标准化降水蒸散指数（SPEI）识别干旱和湿润期模式。应用斯皮尔曼等级相关系数（SR）检验发现 1 个月和 12 个月 SPEI 数据的时间趋势。巴拉科特、迪尔、卡库尔、卡拉姆、马拉姆贾巴、帕拉奇纳尔、帕坦和赛都位于湿润区，而切拉特和提默加拉属于次湿润气象站，而本努、奇特拉尔、德罗什和白沙瓦属于半干旱区，只有迪尔-伊克汉气象站属于干旱区。回归结果表明，巴拉科特、卡库尔和迪尔的降雨量正在减少，而在该省南部地区，降雨量正在增加，如在帕拉奇纳尔和切拉特。SPEI 结果显示，在 1971-1974 年、1984-1989 年、1998-2004 年以及最近的 2017-2018 年，几乎所有气象站都出现了明显的干旱期。SR 结果表明，位于西部的帕拉奇纳尔气象站出现了显著的湿润趋势，而位于研究区东北部的巴拉科特气象站则出现了显著的干燥趋势。详细了解降雨变化可以为水资源规划和利用提供基础。
