Abstract:

This paper explored the variation characteristics of evapotranspiration during the growing season in Changji from 1963 to 2020, aiming to provide a basis for the optimal management of water resources, rational crop planting distribution, agricultural irrigation planning and the development and utilization of water resources. Based on the meteorological data of eight meteorological stations in Changji from 1963 to 2020, the spatial and temporal variation characteristics of potential evapotranspiration were analyzed by Thornthwaite method, climate trend method, M-K test method and wavelet analysis method, and the influence of climate factors on the potential evapotranspiration was discussed by correlation analysis. The results showed that: (1) on the time scale, the potential evapotranspiration in the growing season increased significantly with a change rate of 2.3 mm/10 a and an average annual value of 876 mm; the potential evapotranspiration of 8 meteorological stations showed increasing trends; (2) on the spatial scale, the potential evapotranspiration decreased from west to east in the growing season of crops, as a whole, it showed a trend of decreasing first and then increasing; (3) the mutation occurred in 2009 in the western region, in 1994 in the central region, and in 2013 in the eastern region; the mutation occurred in 1997 in Changji, and the mutation in the central-eastern region was earlier than that in the western-eastern region; the periodic variation showed that the potential evapotranspiration in the growing season of crops had a period of 3.7-4.2 year; (4) temperature was the main factor affecting the potential evapotranspiration in the growing season, and the minimum temperature contributed the most to the increase of the potential evapotranspiration year by year, while the change of other climate factors weakened the potential evapotranspiration.

Key words: potential evapotranspiration, Thornthwaite, spatiotemporal analysis, wavelet power spectrum, factor analysis