Estimation of meteorological drought indices based on AgMERRA precipitation data and station-observed precipitation data

分类： 地球科学 >> 地理学 提交时间： 2017-11-07 合作期刊: 《干旱区科学》

Nasrin SALEHNIA Amin ALIZADEH Hossein SANAEINEJAD Mohammad BANNAYAN Azar ZARRINl Gerrit HOOGENBOOM

摘要： Meteorological drought is a natural hazard that can occur under all climatic regimes. Monitoringthe drought is a vital and important part of predicting and analyzing drought impacts. Because no singleindex can represent all facets of meteorological drought，二took a multi-index approach for droughtmonitoring in this study. We assessed the ability of eight precipitation-based drought indices (SPI(Standardized Precipitation Index), PNI (Percent of Normal Index), DI (Deciles index), EDI (Effectivedrought index), CZI (China-Z index), MCZI (i}Modified CZI), Rr1I (Rainfall Anomaly Index), and ZSI(Z一score Index)) calculated from the station-observed precipitation data and the r}gi}MERRr} griddedprecipitation data to assess historical drought events during the period 1987-?010 for the Kashafrood Basin of Iran. We also presented the Degree of Dryness Index (DDI) for comparing the intensities of different drought categories in each year of the study period (1987-2010). In general, the correlations among drought indices calculated from the AgMERRr1 precipitation data were higher than those derived from the station-observed precipitation data. r1ll indices indicated the most severe droughts for the study period occurred in 2001 and 2008. Regardless of data input source, SPI, PNI, and DI were highly inter-correlated (B2=0.99). Furthermore, the higher correlations (B2=0.99) were also found between CZI and MCZI, and between ZSI and Rr1I. r1ll indices were able to track drought intensity but EDI and Rr1I showed higher DDI values compared with the other indices. Based on the strong correlation among drought indices derived from the AgMERRr1 precipitation data and from the station-observed precipitation data.MERRr1 precipitation data can be accepted to fill the gaps existed in the station-observed precipitation data in future studies in Iran. In addition, if tested by station-observed precipitation data, the :}gi}IERR:} precipitation data may be used for the data-lacking are as.

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