日尺度标准化前期降水蒸散指数在大豆旱涝评估中的适用性分析

Daily standardized antecedent precipitation evapotranspiration index(SAPEI)and its adaptability in the evaluation of soybean drought and flood in Liaoning Province

为监测评价影响大豆丰产增收的旱涝灾害,利用1961—2020年辽宁省51个气象站逐日气象观测资料和土壤水分数据,通过对前期累积降水与蒸散差值指数(Antecedent precipitation evapotranspiration index,APEI)序列值进行三参数的log-Logistic概率分布拟合,建立日尺度标准化前期降水蒸散指数(Standardized antecedent precipitation evapotranspiration index,SAPEI),选取辽宁省4个大豆主产区代表站,对SAPEI在辽宁省大豆旱涝监测评估中的可行性和适用性进行分析。结果表明:不同代表站的log-Logistic概率分布函数与经验概率分布曲线高度拟合,SAPEI曲线能够表征辽宁省大豆的每日农田水分盈亏状况。在2014年8—9月旱涝转变实例分析中,SAPEI旱涝演变特征、旱涝等级与同期土壤水分监测数据具有很好的一致性和同步性,大豆生育期旱涝积指数累年平均值空间分布趋势与辽宁旱涝分布趋势基本一致,表明日尺度SAPEI及旱涝积指数能够反映降水时间、日雨量大小对农田旱涝的影响,可精准描述辽宁省不同区域日尺度的旱涝变化过程及其累积效应,在辽宁省大豆旱涝逐日监测中具有较好的适用性。

Agricultural drought and waterlogging are two of the most compelling problems affecting agricultural productivity and efficiency.Based on the daily meteorological observation data and soil moisture data of 51 meteorological stations in Liaoning from 1961 to 2020,a daily standardized antecedent precipitation evapotranspiration index(SAPEI)was constructed by fitting the daily antecedent precipitation evapotranspiration index(APEI)series with 3-parameter log-Logistic distribution.In addition,the feasibility and applicability of SAPEI were analyzed in 4 representative stations that were selected in main soybean producing areas of Liaoning.The results showed that the log-Logistic probability distribution curve of representative stations highly corresponded with the empirical probability distribution curve.Representative stations’daily SAPEI curve described the change in farmland water budget of soybean in Liaoning Province.In the case of the change in drought and flood from August to September in 2014,SAPEI’s drought and waterlogging grades and change characteristics were in good agreement with soil moisture in the same period.Spatial distribution of drought,waterlogging accumulation,and annual mean values of accumulated index based on soybean whole development stage’s SAPEI were primarily distributed latitudinally.These distribution characteristics conformed to the actual distribution of drought and waterlogging in Liaoning.Therefore,the daily scale SAPEI and antecedent drought and waterlogging index reflected the impact of precipitation time and daily rainfall on farmland drought and waterlogging,accurately depicting the daily scale changes and process cumulative effects of drought and flood in different regions of Liaoning.As a result,the SAPEI can be applied to daily dynamically monitoring the service of soybean drought and flood in Liaoning.