基于简单气象因子的干旱指数计算及其适用性分析  

Calculation and applicability analysis of drought index based on simple meteorological factors

作　　者：刘爽 范兴科[1,2,4] LIU Shuang;FAN Xingke(The Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling,Shaanxi 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]中国科学院大学,北京100049 [4]西北农林科技大学水土保持研究所,陕西杨凌712100

出　　处：《干旱地区农业研究》2024年第1期242-251,共10页Agricultural Research in the Arid Areas

基　　金：“十三五”国家重点研发计划项目(2016YFC0501703);唐仲英基金会资助项目;陕西省现代节水农业工程技术研究中心后补助项目(2021GCZX-16)。

摘　　要：为建立可对短期干旱进行合理监测表征的气象干旱指数,从气象干旱发生的机制——水分供需矛盾(主要为降水量与蒸散量两大因素)出发,以旬尺度的蒸散缺水量占需水量的比值定义一个气象干旱指数——缺水度指数(WSI),潜在蒸散量(PET)采用气温(T,℃)及相对湿度(RH,%)两大极易获取的气象因子计算,同时利用陕西省30个气象站点2000—2020年的逐日气象观测资料分析WSI的适用性特征。结果表明:在不考虑风和大气压的影响条件下,相对于Penman-Monteith方程,基于T和RH估算PET误差较小,均方根误差(RMSE)和平均绝对误差(MAE)均值分别为1.17 mm和0.82 mm,但62.1%的数据计算结果偏小,部分站点80%以上数据偏小。对陕西省不同区域近年来旱情发展变化的研究表明,WSI能够识别出陕西省旱情易发区域及时段,同时对于短期干旱事件具有较强的识别能力,较MCI指数能够更快地捕捉旱情发生,同时更加灵活简便,可以应用于气象干旱的监测预报和评估。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 supply 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 proportion of the water demand.The potential evapotranspiration(PET)was calculated using easily accessible meteorological factors:temperature(T,℃)and relative humidity(RH,%).Using daily meteorological observation data from 30 weather stations in Shaanxi Province from^(2)000 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 estimating 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 outperforms MCI in swiftly detecting droughts,offering greater flexibility and simplicity for monitoring,forecasting,and evaluating meteorological drought conditions.

关 键 词：气象干旱 气温 相对湿度 缺水度指数(WSI) 陕西省 

分 类 号：S165.25[农业科学—农业气象学]