稻田蒸散估算方法及灌溉影响分析

Estimation Methods of Paddy Field Evapotranspiration and Analysis of Irrigation Impact

【目的】寻找合适的蒸散模型及其敏感因子。【方法】以稻田生态系统为研究对象,根据江西省余江县试验区的净辐射、土壤热通量等小气候数据及相关农学观测数据,进行了不同时间尺度3种蒸散模型(Penman-Monteith、Priestley-Taylor和Hargreaves模型)拟合效果的比较以及蒸散对气象因子的敏感性分析,并研究了灌溉对潜在蒸散的影响。【结果】逐日尺度上,Penman-Monteith模型的拟合效果最优,其次为Priestley-Taylor模型,Hargreaves模型较差且低估了实际蒸散值;逐时尺度上,拟合效果较好的是Penman-Monteith模型和Priestley-Taylor模型。【结论】不同时间尺度,蒸散对各个气象因子的敏感性不同,逐日逐时蒸散对净辐射和水汽压较为敏感。不同灌溉处理,Penman-Monteith模型潜在蒸散变化显著,Priestley-Taylor模型变化不明显。

Evapotranspiration plays an important role in water cycle and water balance system.【Objective】Find the suitable evapotranspiration model and sensitive factors.【Method】According to the net radiation, soil heat flux and microclimate data of the experimental area in Yujiang county of Jiangxi province, we analyzed fitting results of the different evapotranspiration models of time scales, the sensitivity analysis of evapotranspiration to weather elements, and the irrigation effects on potential evapotranspiration.【Result】The results showed that the fitting result of Penman-Monteith was the best, and the next was Priestley-Taylor. The result for Hargreaves was bad and it underestimated the actual evapotranspiration on the daily scale. On the hourly scale, the fitting efficiency of Penman-Monteith and Priestley-Taylor model was better. Evapotranspiration had different sensitivities to meteorological factors on different time scales, and evapotranspiration was more sensitive to net radiation and vapor pressure.【Conclusion】In different irrigation treatments, the potential evapotranspiration of Penman-Monteith model has a significant change, which of Priestley-Taylor model has no obvious change.