机构地区:[1]南京信息工程大学气象灾害预报预警与评估协同中心/灾害风险管理研究院/地理科学学院,江苏南京210044 [2]中国气象局国家气候中心,北京100081 [3]中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011
出 处:《干旱区地理》2020年第2期349-359,共11页Arid Land Geography
基 金:科技部基础资源调查专项(2018FY100501);国家自然科学基金委和巴基斯坦科学基金会合作项目(41661144027);国家自然科学基金(41671211)资助。
摘 要:基于印度河流域及周围54个地面气象站气温、降水资料,结合CRU气温和GPCC降水全球格点化陆面再分析资料,通过插值构建了一套0.5°×0.5°分辨率1980-2016年逐月格点数据集。采用Thornthwaite方法计算了潜在蒸散发,基于标准化降水蒸散指数(SPEI),探讨了印度河流域气候变化及干旱演变特征。结果表明:(1)1980-2016年,印度河流域年平均气温以0.30℃·(10 a)-1的速率呈显著上升趋势,21世纪初增温幅度最大;干季(11月~次年4月)升温速率较快,达0.36℃·(10 a)-1,湿季(5~10月)增速0.25℃·(10 a)-1。年降水量呈现少雨-多雨-少雨-多雨年代际振荡。伴随着持续升温,年和各季的潜在蒸发量增加显著。干季干旱频率较多,但湿季干旱强度高,各季干旱频率与降水呈现较一致的年代际波动;干旱的影响面积在干季呈现微弱地增加趋势,湿季却略有减少趋势。(2)空间上,除西北局部,流域其他区域的年和季平均气温、潜在蒸发量增加趋势显著,均达到95%置信水平。其中南部平原和东北山区升温幅度较高,南部平原区潜在蒸发量增加也较大。新德里到喀布尔的东南至西北带状区域的年和湿季降水量,以及喀布尔周围地区的干季降水量呈显著增加趋势。东南平原区和东北局部山区的干季,以及东北和西南局部山区的湿季呈现显著的干旱化态势,需要加强防灾减灾的意识并采取相应措施,以规避干旱增多带来的不利影响。Supported by temperature and precipitation observations from 54 ground-based stations in the Indus River Basin and surrounding areas, we used Climate Research Unit temperature and Global Precipitation Climatology Centre precipitation global land surface reanalysis datasets to construct a new gridded monthly dataset covering the entire Indus River Basin.This dataset achieved a spatial resolution of 0.5°×0.5° for 1980-2016.We derived potential evapotranspiration values with the Thornthwaite model in order to further analyze the drought characteristics in the basin according to the Standard Precipitation Evapotranspiration Index.Our results revealed that the areal averaged annual mean temperatures increased significantly between 1980 and 2016, with a rate of 0.30 ℃ ·(10 a)-1.The most obvious increase occurred in the early 21 st century.On a seasonal timescale, the observed increase was much faster in the dry season(November-April;0.36 ℃ ·(10 a)-1) than it was in the wet season(May-October;0.25 ℃ ·(10 a)-1).Unlike the monotonic increase observed for temperature, annual precipitation revealed a decadal oscillation.Driven by the persistent warming, annual and seasonal potential evapotranspiration rates have increased significantly.We also detected that drought frequency showed decadal fluctuations similar to those of precipitation patterns.Drought was more common in the dry season, but drought intensity is higher in the wet season.Meanwhile, the extent of drought-stricken areas experienced a weak increasing trend in the dry season, but a slight decrease in the wet season.Spatially, the 1980-2016 increases in seasonal and annual temperature and potential evapotranspiration were significant at a 95% confidence level throughout the Indus River Basin, except for a small fraction in the northwestern portion of the region.Warming was sharpest in the southern plain and the northeastern mountain regions, while potential evapotranspiration rose particularly quickly in the southern plain.Over the same period, annual
分 类 号:P426[天文地球—大气科学及气象学] P423.3
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