基于改进的双作物系数模型与Priestley-Taylor模型估算温室黄瓜蒸散量

Estimation of cucumber evapotranspiration in greenhouse based on improved dual crop coefficient model and Priestley-Taylor model

为估算温室黄瓜植株蒸腾(T_(r))与土面蒸发(E_(g)),基于2018年春夏茬和秋冬茬温室内实测微气象数据、黄瓜作物叶面积指数(LAI)及根区土壤水分数据,对FAO-56推荐的双作物系数模型(Dual-K_(c))及Priestley-Taylor(P-T)模型中参数进行修正,应用修正后的Dual-K_(c)和P-T模型(M-PT)估算温室黄瓜蒸散量(ET_(c)),利用2019年春夏茬和秋冬茬实测数据对模型精度进行验证.结果表明:改进后的Dual-K_(c)和M-PT模型估算的温室黄瓜ET_(c)和T_(r)与实测值有较好的一致性,但M-PT模型的估算误差高于Dual-K_(c)模型,Dual-K_(c)模型估算春夏茬与秋冬茬黄瓜ET_(c)与实测值的均方根误差(RMSE)、平均绝对误差(MAE)、偏离率(Bias)和相关系数(R^(2))分别为0.36 mm/d,0.28 mm/d,-0.10和0.98(春夏茬)及0.28 mm/d,0.22 mm/d,-0.11和0.97(秋冬茬);M-PT模型的RMSE,MAE,Bias和R^(2)分别为0.48 mm/d,0.42 mm/d,-0.17和0.97(春夏茬)及0.41 mm/d,0.31 mm/d,-0.24和0.95(秋冬茬).尽管M-PT模型估算误差较Dual-K_(c)略高,但其结构简单、所需参数较少,在温室作物蒸散量估算中更值得推广.

In order to estimate the transpiration(T_(r))and soil evaporation(E_(g))of cucumber plants in greenhouse conditions,based on the micro-meteorological data(measured in a greenbouse in spring-summer and autumn-winter planting seasons in 2018),cucumber crop leaf area index(LAI)and root soil moisture data in the area,the parameters in the dual crop coefficient model(Dual-K_(c))and Priestley-Taylor(P-T)model recommended by FAO-56 were corrected,and the revised Dual-K_(c)andP-T models were applied(M-PT)to estimate greenhouse cucumber evapotranspiration(ET_(c)).The measured data of spring-summer and autumn-winter crops in 2019 were used to venify the accura-cy of the model.The results show that the ET_(c)and Tc caleulated by the improved Dual-K_(c)and M-PT models have a good agreement with the measured values,and the performance of the Dual-K_(c)model is better than that of the M-PT model.The root mean square error(RMSE),mean absolute error(MAE),deviation rate(Bias)and correlation cofficient(R^(2))of the Dual-K_(c)model in predicting cu-cumber ET_(c)are 0.36 mm/d,0.28 mm/d,-0.10 and 0.98 for spring-summer planting season,and 0.28 mm/d,0.22 mn/d,-0.11 and 0.97 for autumn-winter planting season,respectively.The RMSE,MAE,Bias and R^(2)of M-PT model are 0.48 mm/d,0.42 mm/d,-0.17 and 0.97 for spring-summer planting season and 0.41 mm/d,0.31 mm/d,-0.24 and 0.95 for autumn-winter planting season,respeetively.Although M-PT model has a slightly higher estimation error than Dual-K_(c)model,its simple structure and fewer parameter requirements make it more worthy of application in the estimation of greenbouse crop evapotranspiration(ET_(c)).