1980—2020年气候变化对塔里木河流域棉花生产的影响

Impact of Climate Change on Cotton Production in Tarim River Basin, 1980—2020

摘要:

棉花生产对气候变化的反馈机制是棉花种植规划和稳产的重要科学依据。然而,“气候-管理-作物”三元交互对塔里木河流域棉花生产的影响仍不清晰。为此,本研究基于气象观测数据和校准后DSSAT-CROPGRO-Cotton作物模型,揭示了1980—2020年“气候-管理-作物”下塔里木河流域棉花产量、全生育期和灌溉量的时空变化特征,基于情景扰动评估了棉花生产对气候因子耦合下的综合敏感性。结果表明：1980—2020年间,塔里木河流域棉花生长季气温显著增加,最低气温升温速率高于最高气温,降水量稀少且年度变异大,辐射量降低不显著。早播对提高产量有巨大潜力,较传统播期可增产8.7%,但早播带来的气候风险依然存在。早播延长了全生育期,增加了所需灌溉量。流域尺度上,棉花产量呈显著增加趋势,增速为22.3 kg/(hm^2·a);全生育期呈显著缩短趋势,变化速率为-0.539 d/a;灌溉量呈不显著减少趋势,变化速率为-0.650 mm/a。最高气温已处于产量“积极-消极”转变窗口,最高气温升高和辐射量降低对产量影响消极,但最低气温和CO2浓度升高补偿了该影响并促使产量增加。综上,1980—2020年气候变化对塔里木河流域棉花生产总体呈正向影响,早播是应对气候变化的有效措施,研究结果为未来棉花生产提供了数据参考。

Abstract:

The feedback mechanisms of cotton production to climate change constitute a critical scientific basis for planting planning and yield stabilization. However, the impacts of the "climate-management-crop" triple interaction on cotton production in the Tarim River Basin remain poorly understood. Based on meteorological observation data and a calibrated DSSAT-CROPGRO-Cotton crop model, the spatiotemporal variation characteristics of cotton yield, whole growth duration, and irrigation water requirement in the Tarim River Basin from 1980 to 2020 under the framework of "climate-management-crop" was firstly revealed. Subsequently the integrated sensitivity of cotton production to coupled climatic factors was evaluated by using scenario perturbation experiments. The results indicated that during 1980—2020, the cotton growing season in the Tarim River Basin experienced a significant increase in air temperature with the warming rate of minimum temperature exceeding that of maximum temperature. Precipitation remained scarce with large inter-annual variability, and solar radiation showed a non-significant declining trend. Early sowing demonstrated substantial potential for yield improvement, increasing yield by 8.7% compared with the conventional sowing date;however, the associated climatic risks persisted. Early sowing prolonged the whole growth duration and increased irrigation water demand. At the basin scale, cotton yield exhibited a significant increasing trend at a rate of 22.3 kg/(hm^2·a);the whole growth duration showed a significant shortening trend at a rate of -0.539 d/a;and irrigation water requirement displayed a non-significant decreasing trend at a rate of -0.650 mm/a. Maximum temperature approached the critical transition window from positive to negative effects on yield. Elevated maximum temperature and reduced radiation level exerted negative impacts on yield, yet these were compensated by concurrent increases in minimum temperature and CO2 concentration, resulting in a net yield gain. In conclusion, climate change exerted an overall positive influence on cotton production in the Tarim River Basin during 1980—2020,and early sowing represented an effective adaptation strategy. The research result can provide quantitative data references for future cotton production under continued climate change.