甘孜州青稞生育期干旱强度变化分析

Change Analysis on Drought Intensity during the Growth Stage of Highland Barley in Ganzi

摘要:

在气候变化背景下，气温升高、降水量分布不均，甘孜州青稞生产受干旱的影响加剧。为了进一步了解干旱强度对青稞各生育期的影响，利用1981—2022年甘孜州青稞主要种植区12个气象站逐日气象数据计算了逐日气象干旱综合指数（MCI），通过Mann-Kendall突变检验、Morlet小波分析和基于重标极差（R/S）分析的Hurst指数，分析了青稞各生育期干旱强度的时空分布和趋势变化。结果表明：（1）干旱强度在分蘖－抽穗期呈减弱趋势，在其他生育期呈增强趋势，抽穗－成熟期增强趋势较播种－分蘖期和全生育期明显。（2）各生育期干旱强度在20世纪90年代和21世纪20年代均出现突变，在1985年播种－分蘖期和2002年分蘖－抽穗期呈显著减弱趋势。（3）各生育期干旱强度最强区均在西南部的得荣，巴塘、乡城、稻城县次之，呈现由东北向西南增强的分布特征。（4）未来10年干旱强度在播种－分蘖期、抽穗－成熟期和全生育期有持续增强趋势，在分蘖－抽穗期有持续减弱趋势。甘孜州青稞各生育期干旱强度时间变化特征存在显著差异，空间分布特征具有相似性。

Abstract:

Against the context of climate change, with rising temperature and uneven distribution of precipitation, the production of highland barley in Ganzi is increasingly affected by drought. Based on the daily meteorological data of 12 meteorological stations in the main barley planting areas of Ganzi from 1981 to 2022, the daily Meteorological drought Comprehensive Index (MCI) was calculated. The Mann-Kendall mutation test, Morlet wavelet analysis, and Hurst exponent based on ReScaled range (R/S) analysis were employed to examine the spatial-temporal distribution and change trends of drought intensity across various growth stages in Ganzi. This analysis aims to further comprehend the impact of drought intensity on various growth stages of highland barley. The results showed that: (1) Drought intensity exhibited a decreasing trend during the tiller-heading stage, while it increased during other growth stages. Drought intensity during the head-maturity stage was significantly higher than that during the sow-tillering stage and the entire growth stage. (2) Drought intensity in each growth stage experienced abrupt mutations in both the 1990s and the 2020s, while exhibited a significant decrease during the sow-tillering stage in 1985 and the tiller-heading stage in 2002. (3) The regions with the strongest drought intensity across different growth stages were located in Derong, the southwestern part of Ganzi, followed by surrounding counties such as Batang, Xiangcheng, and Daocheng, showing a distribution pattern that increases from the northeast to the southwest. (4) Over the next decade, drought intensity was projected to show a continuous drying trend during the sow-tillering stage, head-maturity stage and the entire growth stage, while the tiller-heading stage was expected to experience a continuous wetting trend. The temporal variation characteristics of drought intensity during different growth stages of highland barley in Ganzi show significant differences, while the spatial distribution characteristics exhibit similarities.