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为评价生态模型在农田蒸散及土壤水分运动模拟中的适用性,利用2013—2015年南京农业气象测站观测数据,评估了BEPS(Boreal Ecosystem Productivity Simulator)模拟冬小麦农田生态系统逐日蒸散及与土壤水分动态的可靠性,并进一步开展了植被冠层蒸腾和农田土壤蒸发分离。模拟结果表明:BEPS适用于研究冬小麦农田蒸散量及土壤水分运动规律;由于考虑了叶片聚集指数和冬小麦根系垂直分布递减系数随生育期变动的参数化改进,BEPS分别可以解释2013—2014年和2014—2015年两个生长季农田生态系统蒸渗仪实测蒸散量变化的83%和74%,参数化改进前后模型效率ME相当(前:0.8,后0.74),标准差RMSE(前:1.50,后1.05),平均偏差MBE(前:0.5,后0.35),误差减小;两个生长季中,土壤蒸发占冠层上方总蒸散的比例随生育进程而变化,全生育期发散比平均值分别为34%和29%;BEPS模拟的0~40 cm土层深度土壤水分随时间变化趋势与实测值基本一致,可以解释78%以上的土壤水分实测值变化,并能快速地响应降水变化。本研究表明,生态模型可以用于模拟冬小麦农田蒸散和土壤水分变化,并有助于厘定农田冠层中难以区分的植被蒸腾和土壤蒸发的比例关系,可为进一步开展气候变化背景下的区域蒸散发评估及与之相联系的农田节水管理奠定基础。
In order to evaluate the applicability of ecological models in farmland evapotranspiration and soil water movement simulation, the daily evapotranspiration of simulated winter wheat farm ecosystem using BEPS (Boreal Ecosystem Productivity Simulator) was evaluated based on the observation data of Nanjing Agricultural Meteorological Station from 2013 to 2015, Dynamic reliability, and further carry out the vegetation canopy transpiration and farmland soil evaporation separation. The simulation results show that BEPS can be used to study the evapotranspiration of winter wheat field and the law of soil water movement. Due to the parametric improvement of leaf aggregation index and winter wheat root vertical distribution decreasing coefficient with the growth period, BEPS can explain the changes of soil water regimes between 2013-2014 and 2014 - Measured Evapotranspiration Evapotranspiration measured 83% and 74% of evapotranspirator in two growing seasons in 2015. The model efficiency before and after parametric improvement ME was comparable (before: 0.8, after 0.74), standard deviation RMSE (before: 1.50, after 1.05). The mean deviation MBE (before: 0.5, after 0.35), the error decreased. The proportion of soil evaporation to total evapotranspiration above the canopy changed with the growth process in two growing seasons, the average growth divergence was 34 % And 29%, respectively. The trend of soil moisture over the depth of 0-40 cm simulated by BEPS was basically consistent with the measured values, which could explain the changes of soil moisture above 78% and respond quickly to the changes of precipitation. This study shows that the ecological model can be used to simulate the evapotranspiration and soil moisture changes of winter wheat and help to determine the proportionate relationship between the vegetation transpiration and soil evaporation in the canopy that is difficult to distinguish. Evaluation and associated with the establishment of water-saving farmland management foundation.