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| Characteristics and causes of potential evapotranspiration in Ningxia Region |
| LI Chen, LI Wangcheng, DONG Yaping, WANG Shuangtao, WANG Xing, ZHAO Yan |
| 1. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan, Ningxia 750021,China; 2. Engineering Technology Research Center of Water-Saving and Water Resources Regulation in Ningxia, Yinchuan, Ningxia 750021, China; 3. Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions, Ministry of Education, Yinchuan, Ningxia 750021, China |
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Abstract According to the daily meteorological data of 11 national meteorological stations in Ningxia from 1962 to 2017, the Penman-Monteith formula was used to calculate the potential evapotranspiration(ET<sub>0</sub>)daily value series in Ningxia, using climate tendency rate and Mann-kendall mutation test. ArcGIS inverse distance weighted spatial interpolation, sensitivity analysis and contribution contribution rate are used to analyze the temporal and spatial variation characteristics and influe-ncing factors of ET<sub>0</sub> in Ningxia. The results show that the average ET<sub>0</sub> of Ningxia region from 1962 to 2017 is 1 073 mm, of which the highest in the central arid zone(1 135 mm), the third in the Yellow River irrigation area(1 095 mm), the lowest in the southern mountainous area(893 mm); the Ning-xia ET<sub>0</sub> in 1986 The mutation occurred, and the amplitude decreased by 0.571 mm/a before the mutation, and increased by 0.109 mm/a after the mutation. The whole period increased by 0.523 mm/ad, but the variation range was not significant. ET<sub>0</sub>has different sensitivity to meteorological elements in different regions. The Yellow River irrigation area and the central arid zone are most sensitive to the hig-hest temperature, the sensitivity coefficients are 0.41 and 0.43 respectively, and the southern mountainous areas are relative humidity(-0.45). The contribution rate of ET<sub>0</sub> is different. The dominant factor in the Yellow River irrigation area and the southern mountain area is the lowest temperature, and the central arid zone is the average wind speed. Before and after the mutation, the meteorological elements with the highest contribution rate to ET<sub>0</sub> in the Yellow River Irrigation District, the Central Arid Zone and the Southern Mountain Region were changed from average wind speed, relative humidity and minimum temperature to relative humidity, average wind speed and minimum temperature.
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Received: 06 January 2021
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