摘要
为评价农田灌溉水利用状况并揭示灌溉水利用效率的尺度变化规律,应用改进的分布式水文模型(SWAT)模拟了漳河灌区三干渠灌域的水循环过程和作物产量。以子流域嵌套方式将研究区划分为9个尺度来计算灌溉水利用效率指标,并分析其随尺度变化的特征及原因。结果表明,灌溉水分生产率受降雨、气候条件的时空分布特征影响较大,而且随尺度增大明显,其尺度关系可以近似应用幂函数描述,函数的形式和参数与分形思想接近。排水率在中等尺度上的数值最大,但随尺度变化不显著。因此,在一定精度条件下,灌溉水分生产率的尺度转换模式可以尝试应用幂函数形式。漳河灌区在中等尺度上的节水潜力最大。
To better assess water use status in irrigated agriculture and understand irrigation water use efficiency （IWUE） at different spatial scales,an improved distributed hydrological model,soil and water assessment tool （SWAT）,is used to simulate hydrological processes and the crop yields in the irrigation region of the third main canal in Zhanghe irrigation district.The nine nesting scales is adopted to calculate the IWUE and to result in five IWUE indexes.The variation of five assessment indexes with the nine nesting scales is analyzed.Results show that one of the indexes,the irrigation water productivity,is greatly influenced by the spatial-temporal distribution of precipitation as well as other weather conditions in the irrigation region.Its values increase with nesting scales.This scale character can be approximately represented by a power function that is similar to the fractal principle.Another important index,the water drainage ratio,achieves the maximum value at the intermedium nesting scale.However,the scale character of the water drainage ratio is insignificant as this index is quasi-stationary across all nesting scales.Therefore,the power function can be used to scale up/down the irrigation water productivity.The greatest potential for water-saving practice in this irrigation region is achievable at the intermedium nesting scale.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2010年第5期681-689,共9页
Advances in Water Science
基金
国家自然科学基金资助项目(50879060
50839002)~~
关键词
分布式水文模型
灌溉水利用效率
水分生产率
排水率
尺度
节水潜力
distributed hydrological model
irrigation water use efficiency
water productivity
drainage ratio
scaling
potential of water-saving irrigation
