银川市近50年参考作物蒸散量变化特征及影响因子分析

Based on the crucial role of the crop evapotranspiration in the regional hydrological cycle and water use, this paper selected long-term observations meteorological elements such as air temperature, relative humidity, wind speed and sunshine hours and used the Penman-Monteith equation to calculate the reference crop evapotranspiration(ET0) of the Yinchuan from 1960 to 2009. The change characteristic and effect factors of ET0 was analyzed using the methods of Mann-Kendall test and partial correlation. The results show that⑴the reference crop evapotranspiration had a increasing trend in the recent 50 years in Yinchuan, and the linear trend rate was 38.5mm/10a;⑵the air temperature and wind speed was rising, especially during the 1990s, increased significantly, while the relative humidity and sunshine hours had decreased.⑶the increacing wind speed and decreasing ralative humidity at the same period appear to the major causes for the positive trend of the reference crop evapotranspiration, followed by sunshine hours, but the influence of air temperature is not obvious.