Calculation and applicability analysis of drought index based on simple meteorological factors
In order to establish a meteorological drought index that can effectively monitor short-term droughts,this study,based on the mechanism of meteorological drought occurrence-namely the imbalance between water sup-ply and demand(primarily influenced by precipitation and evapotranspiration),introduced a drought index termed the water scarcity index(WSI).This index was defined by the ten-day scale evapotranspiration deficit as a propor-tion of the water demand.The potential evapotranspiration(PET)was calculated using easily accessible meteoro-logical factors:temperature(T,℃)and relative humidity(RH,％).Using daily meteorological observation data from 30 weather stations in Shaanxi Province from 2000 to 2020,we analyzed the applicability characteristics of WSI.The results indicated that,without considering the effects of wind and atmospheric pressure,the error in esti-mating PET based on T and RH was relatively small compared to the Penman-Monteith equation.The root mean square error(RMSE)and mean absolute error(MAE)were 1.17 mm and 0.82 mm.However,62.1％of the data results were underestimated,with some stations having over 80％of data underestimated.Research on the recent drought development changes in different regions of Shaanxi Province showed that WSI can identify drought-prone areas and periods in Shaanxi.It also possesses a strong ability to recognize short-term drought events.WSI outper-forms MCI in swiftly detecting droughts,offering greater flexibility and simplicity for monitoring,forecasting,and e-valuating meteorological drought conditions.
meteorological droughtair temperaturerelative humiditywater scarcity index(WSI)Shaanxi Province
国家科技期刊平台
NSTL
万方数据
维普
