CAJ | 학술논문

Penman-Monteith法是FAO-56推荐的计算潜在蒸散量的标准方法,但由于涉及的气象要素较多,难于在业务中应用.以综合气象干旱指数的业务化应用为目标,利用1971-2000年四川省156个气象站的观测资料,以Penman-Monteith法计算结果作为标准,分析了Thornthwaite法和Hargreaves法对川西高原和四川盆地年、月潜在蒸散量的估算精度,建立了可供业务应用的E_(T0)估算模型,并应用于2006年四川省特大伏旱监测,结果表明:Thornthwaite法反映不出E_(T0)的年际变化,在冬季显著偏小,而Hargreaves法对E_(T0)的年际变化具有较好的反映能力,与rhornthwaite法相比,其E_(T0)年、月估算值更接近于Penman-Monteith法标准值,且Hargreaves法估算值与Penman-Monteith法标准值之间具有较好的线性关系,引入风速和相对湿度两个订正因子后,Hargreaves订正值的误差可控制在10%以内,基于该文E_(T0)估算模型计算的综合气象干旱指数对四川干旱具有较强的监测能力.
Penman-Monteith법시FAO-56추천적계산잠재증산량적표준방법,단유우섭급적기상요소교다,난우재업무중응용.이종합기상간한지수적업무화응용위목표,이용1971-2000년사천성156개기상참적관측자료,이Penman-Monteith법계산결과작위표준,분석료Thornthwaite법화Hargreaves법대천서고원화사천분지년、월잠재증산량적고산정도,건립료가공업무응용적E_(T0)고산모형,병응용우2006년사천성특대복한감측,결과표명:Thornthwaite법반영불출E_(T0)적년제변화,재동계현저편소,이Hargreaves법대E_(T0)적년제변화구유교호적반영능력,여rhornthwaite법상비,기E_(T0)년、월고산치경접근우Penman-Monteith법표준치,차Hargreaves법고산치여Penman-Monteith법표준치지간구유교호적선성관계,인입풍속화상대습도량개정정인자후,Hargreaves정정치적오차가공제재10%이내,기우해문E_(T0)고산모형계산적종합기상간한지수대사천간한구유교강적감측능력.
Penman-Monteith formula is a standard method recommended by FAO-56 to calculate potential evapotranspiration.But it is difficult to apply in practical operation as not all related meteorological elements can be obtained in reality,so estimation models are used instead.In order to apply compound drought index in operation,Thornthwaite method and Hargreaves method for yearly and monthly potential evapotranspiration of Sichuan Basin and West Sichuan Plateau are studied.The observation data of 156 meteorological stations in Sichuan Province from 1971 to 2000 are investigated including minimum temperature,maximum temperature,wind speed,relative humidity,and sunshine hours.Using result of Penman-Monteith formula as the E_(T0) standard value,the precisions of the two T_(T0) estimation methods are analyzed.Comparing wind speed,relative humidity,Hargreaves method and Penman-Monteith method statistically,an operational Hargreaves method is established.These Hargreaves method and model have been applied to monitor serious summer drought in 2006 in Sichuan Province.The results show:As far as annual variation is concerned,annual value fluctuation estimated by Thornthwaite method is small so that it cannot reflect the E_(T0) annual variation.However,Hargreaves method and PM method show basically consistent changing tendency and can reflect the E_(T0) annual variation characteristics better. As for the annual mean,result of Thornthwaite method is significantly smaller. The error in the Basin is -10%--20% and -40%-- 60% on Plateau.Result of Hargreaves method is relatively smaller in Plateau and larger in Basin.But its error is 10%-15% ,better than Thornthwaite's.As for the seasonal variation,error of Thornthwaite method is larger in winter but smaller in summer.Due to the influence of relative humidity and wind speed,seasonality of Hargreaves method's error is not obvious.The error of Hargreaves is smaller than that of Thornthwaite especially in Plateau region except for in summer.Results of Penman-Monteith formula and Hargreaves method show good linear relation.With the recovery factors air velocity and relative humidity introduced,the error of Hargreaves correction value can be controlled within 10%.It can meet the demand of practical operation for precision.The compound drought index calculated by this E_(T0) estimation model has strong capability for drought monitoring in Sichuan Province.