基于气温预报的HS公式短期逐日参考作物腾发量预报评价与分析

摘要

The aim of this research is to evaluate and analyze the forecasting of short-term daily reference crop evapotranspiration by Hargreaves-Samani equation based on temperature forecast.The observed daily meteorological data from 2002 to 2013 at Nanjing Station and the daily weather forecast data for 7-day forecast period from 2012 to 2013 are collected,and the daily ET0 was calculated by using the FAO-56 Penman-Monteith (PM) equation according to daily meteorological data from 2002 to 2012.Furthermore,parameters in the HS equation are calibrated with 2002-2012 PM ET0 values and the calibrated HS equation is adopted for forecasting the 7-day ET0 with weather forecast data from 2012 to 2013.The precision and sensitivity of the forecast results are evaluated and analyzed.Results showed that the forecast result of ET0 based on minimum temperature is more accurate than that on maximum temperature;the statistical indicators of calibrated HS equation are good,indicating the accuracy has improved;and the ET0 estimated from calibrated HS equation are in accordance with the ET0 estimated from PM equation,the accuracy of the HS equation has been significantly improved.Moreover,the accuracy of ET0 declines with the increase of forecast period;the error in ET0 is usually more sensitive to maximum temperature than that to minimum temperature,and the error in ET0 is most sensitive to temperature forecasts in summer,while least sensitive to temperature forecasts in winter.%为了开展基于气温预报Hargreaves-Samani (HS)公式短期逐日参考作物腾发量预报评价分析,收集南京站2002-2013年逐日观测气象数据和2012-2013年预见期7d的逐日天气预报数据,采用FAO-56 Penman-Monteith(PM)公式及2002-2012年气象数据计算逐日ET0(参考作物腾发量),并对Hargreaves-Samani (HS)公式参数进行率定.采用率定后的HS公式开展2012-2013年预见期7d的ET0预报,并对预报结果进行精度评价和敏感性分析,结果表明:最低温度预报准确率要高于最高温度;校正后的HS公式各相关统计指标较好,HS公式ET0计算校正值与PM公式计算值总体上一致,校正后的HS公式精度得到提高;ET0预报精度随预见期增加而下降,且基于最低温预报的ET0预报精度要高于最高温度;ET0预报误差对低温预报的敏感性要小于高温预报,ET0预报误差对夏季温度预报误差敏感性最大,而对冬季温度预报误差敏感性最小.