灌溉制度优化对黑河流域绿洲气候的量化影响研究

Quantitative impact of irrigation schedule optimization on the oasis climate in the Heihe River Basin

分析灌溉活动对农田气候的影响特征对准确认识影响我国西北干旱地区农业需耗水变化要素具有重要意义,虽然灌溉气候效应研究已经比较广泛,但目前对灌溉制度变化影响农田气候的机制并不清晰。为明晰灌溉制度对农田气候的影响效应,本文基于中尺度气候模式WRF(Weather Research and Forecasting),对比分析了不同灌溉制度下农田气候要素和潜在蒸散发量的变异特征。研究显示,黑河流域绿洲灌溉水量减少和灌溉次数增加显著增加了地表温度约0.04~0.16℃,“冷化效应”增强约0.2~1.2℃,空气相对湿度增加约2%~14%,潜在蒸散发量增加约0.14~0.16 mm/d。灌溉制度优化改变了黑河流域绿洲气候条件,其中,灌溉水量减少和灌水时间优化分配对绿洲气候变化具有协同效应,故在灌溉气候效应研究中应充分考虑灌溉制度的影响。

Investigating the impact of irrigation on farmland climate is crucial for a precise understanding of the factors influencing agricultural water consumption in the northwest region of China.Despite extensive research on the climatic effects of irrigation,the mechanisms of irrigation schedule changes affecting farmland climate are not well-understood at present.In order to clarify the effect of irrigation schedule on farmland climate,the variations of farmland climate and potential evapotranspiration with changes in the irrigation schedule are simulated and analyzed in the paper,utilizing the mesoscale climate model WRF(Weather Research and Forecasting).The decrease in irrigation amount and the rise in irrigation frequency in the oasis of Heihe River Basin(HRB)significantly increase the surface temperature by approximately 0.04-0.16℃.This also leads to an enhanced‘cooling effect’of about 0.2-1.2℃,an increase in the relative humidity by approximately 2%-14%,and a rise in potential evapotranspiration by about 0.14-0.16 mm day.The optimization of the irrigation schedule alters the farmland climate in the oasis of HRB,in which the reduction of irrigation amount and the optimal allocation of irrigation time exhibit a synergistic impact on the oasis climate.Therefore,the influence of irrigation schedule should be fully considered in the study of irrigation climate effect.