Reference crop evapotranspiration(ET 0) is a key parameter to calculate crop water requirements.In the paper,ET 0 during 1960-2005 was calculated with FAO-56 PM in eastern agricultural areas of Qinghai,China.Then the ...Reference crop evapotranspiration(ET 0) is a key parameter to calculate crop water requirements.In the paper,ET 0 during 1960-2005 was calculated with FAO-56 PM in eastern agricultural areas of Qinghai,China.Then the sensitivity coefficients of ET 0 to meteorological variables were estimated through the nondimensional partial derivative in FAO-56 PM.Results show that the mean annual ET 0 of the whole area is 904 mm,and ET 0 portrays a very significant decrease during the 46 years.In spatial,ET 0 decreases from southeast to northwest,firstly increases then decreases from southwest to northeast.Through sensitivity analysis,in spring the most sensitive variable is relative humidity,while in summer is temperature.The temperature,sunshine duration and wind speed sensitivity coefficients(S(TA),S(n),S(u)) are higher in middle areas as opposed to surrounding areas,while the relative humidity sensitivity coefficient(S(RH)) has an opposite distribution rule.展开更多
基金supported by the Chinese National Natural Science Foundation (51009101)Public Welfare Projects of Ministry of Water Resources in China (201101038)Key Laboratories Open Fund in Sichuan Province-Water-saving Agricultural Research in Southern Hillside Region of China (CJS201201)
文摘Reference crop evapotranspiration(ET 0) is a key parameter to calculate crop water requirements.In the paper,ET 0 during 1960-2005 was calculated with FAO-56 PM in eastern agricultural areas of Qinghai,China.Then the sensitivity coefficients of ET 0 to meteorological variables were estimated through the nondimensional partial derivative in FAO-56 PM.Results show that the mean annual ET 0 of the whole area is 904 mm,and ET 0 portrays a very significant decrease during the 46 years.In spatial,ET 0 decreases from southeast to northwest,firstly increases then decreases from southwest to northeast.Through sensitivity analysis,in spring the most sensitive variable is relative humidity,while in summer is temperature.The temperature,sunshine duration and wind speed sensitivity coefficients(S(TA),S(n),S(u)) are higher in middle areas as opposed to surrounding areas,while the relative humidity sensitivity coefficient(S(RH)) has an opposite distribution rule.
