干旱灌区作物需水量分布特征及未来需水变化响应OA

To explore the distribution characteristics of crop evapotranspiration and water demand in arid Xinjiang irrigation areas,the impact of climate factors on crop water demand,and the response strategies of future crop water demand changes in irrigation areas,based on a 68 years long series of meteorological data from 1952 to 2019,coupled with the results of crop irrigation experiments and irrigation water quotas,the correlations between climatic factors and crop water demand are analyzed.The results indicate that:1)The spatiotemporal variation characteristics and correlation scale of crop evapotranspiration ET0 and water demand ETc shows:ET0 and ETc appear a slight downward trend from 1952 to 2010,and then showing an upward trend after 2010.The ratio of ETc to ET0 is 0.76,and the average tendency rate of ETc and ET0 decreases by 26.48-34.99mm every 10 years.ET0 and ETc oscillate significantly every 9-19 years,experiencing four cycles of"more-less-more-less"during this period,with 9-12 year cycle oscillation,and the average annual ET0 and ETc are between 609-972mm and 463-738mm,respectively.2)The seven meteorological factors have a comprehensive effect of mutual growth and decline on ET0.Temperature and wind speed have a marginal increasing effect on ET0,precipitation,sunshine,water vapor pressure,relative humidity,and evaporation have an unstable and discontinuous effect on ET0,with the frequency of their impact on ET0 being:precipitation＞sunshine hours＞water vapor pressure＞relative humidity＞evaporation.3)As to the impact of future climate change on the ETc in irrigation areas,it is predicted that in the next 20 years(2025-2045),the ETc in irrigation areas will increase by 39-172mm due to rising temperatures,slight increases in wind speed and precipitation,slight decreases in relative humidity in many areas,and slight increases in evaporation.This is equivalent to the 45mm drip irrigation quota benchmark and an increase of 0.9-3.8 irrigation times.The analysis demonstrates that the contradiction between supply and demand of irrigation water resources will become more prominent in the future,providing a basis for efficient,intelligent,water-saving and new quality productivity response strategies for sustainable utilization of water resources in irrigation areas.