基于土壤湿润体特征值的无压灌溉灌水定额模型研究  被引量:3

Study on Irrigation Quota Model of Non-Pressure Irrigation Based on Characteristics Value of Wetted Soil Volume

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作  者:赵伟霞[1] 蔡焕杰[1] 陈新明[1] 单志杰[1] 王健[1] 

机构地区:[1]西北农林科技大学,陕西杨凌712100

出  处:《节水灌溉》2008年第12期5-8,共4页Water Saving Irrigation

基  金:国家自然科学基金(50779059);国家高技术研究发展计划("863"计划)项目(2006AA100202)

摘  要:根据无压灌溉土壤湿润体形状为球冠的特点及湿润体内含水率分布规律,推导出了湿润体特征值模型。该模型表明湿润体特征值仅是灌溉水量的函数,因此可以用该模型计算无压灌溉灌水定额。通过微灌灌水定额计算方程和湿润体特征值模型的比较和联立求解,分别推导出了当湿润体半径(即根据作物根系分布规律来确定湿润体半径大小)为已知条件和湿润比为已知条件时的灌水定额计算方程,并用实例进行了验证。通过求湿润体内平均含水率的方法,解决了大田试验中用张力计监测土壤水分动态变化,从而实现适时精确灌水时张力计具体埋设位置的问题。结果表明,与微灌灌水定额计算方法相比,基于土壤湿润体特征值的灌水定额模型简单,操作性强,误差小,且同时扩大了微灌灌水定额计算方法在无压灌溉技术中的推广和应用范围。According to spherical crown shape or sphere shape of wetted soil volume and distribution rule of soil water content under non-pressure irrigation, the characteristics value model is deduced. The model indicates that wetted radius is only a function of cumulative infiltration, so the model can be used as computing model of irrigation quota under non-pressure irrigation. Through the comparison and simultaneous solution between irrigation quota computing method of micro irrigation and characteristics value model, the irrigation quota computing equations when wetted radius or wetted percentage is known are deduced, respectively. The results indicate that, compared with micro irrigation computing method, the irrigation quota computing method based on characteristics value model is simply and easy to operate. At the same time, the model enlarged the application range of micro irrigation computing method in non-pressure irrigation technique.

关 键 词:无压灌溉 特征值 模型 灌水定额 

分 类 号:S275.6[农业科学—农业水土工程] S274.1[农业科学—农业工程]

 

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