GLEAMS模型在我国东南地区模拟硝氮淋失的检验

利用我国东南亚热带地区农业小流域不同土地利用方式的硝氮渗漏淋失实测数据检验了GLEAMS(Groundwater Loading Effects of Agricultural Management Systems)模型在该地区的适用性。通过现场试验和实地调查并结合模型手册,获取模型所需的水文和营养盐参数,参考模型参数的敏感性分析结果对模型进行调试。结果表明模型对水稻田除外的其它土地利用方式的硝氮渗漏淋失模拟效果较好。水稻田渗漏模拟效果差的主要原因在于模型的水分平衡方程不能反应水稻田长期淹水的实际情况。模型模拟结果的精度可以接受,从而验证了GLEAMS模型在该流域的适用性。

Testing GLEAMS for Nitrate Leaching Modeling in an Agricultural Catchment of Southeast China

GLEAMS(Groundwater Loading Effects of Agricultural Management Systems)model was introduced to test and validate nitrate leaching in an agricultural catchment in southeast China.Field experiments were performed under different landuses such as paddy,bananas and vegetables,in Wuchuan catchment of Fujian Province with the area of 9.6 km2.Eight boreholes were drilled and monitoring pipes were installed for continuous monitoring of nitrate leaching from April to December in 2002.The hydrologic and nutrient parameters of GLEAMS model were extracted based on measurements and experiments during the main crop growing season.Model parameters were tuned to achieve desired agreements between measurements and model simulations based on sensitivity analysis.After calibration and validation,the model generally had acceptable performances in simulating nitrate leaching throughout the landuses with an exception in paddy field.The model simulations can be used to specifically establish best management practices for nutrient management and pollution mitigation in the catchment.