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利用四川省135个气象台站1961~2014年逐日气象资料和29个农业气象观测站的小麦观测资料,选取水分盈亏指数作为干旱评估指标,分析了54年来四川小麦7大种植区不同生育期的各级干旱时空变化特征及其风险分布情况。结果表明:小麦各生育期发生干旱站均次数以川西南山地最多,其多年平均值达0.9以上,可谓十年九旱。各区干旱站均次数的时间变化趋势不明显。生育阶段以孕穗-抽穗期发生干旱频率较高,其次是拔节-孕穗期,最低的是抽穗-乳熟期。从干旱频率空间分布特征来看,川西南山地是发生轻旱频率最高的地区,川西高原中旱和重旱的发生频率要高于其它各区,盆地各区域中只有盆中和盆西部分区域发生干旱频率相对较高。小麦干旱风险分布情况为川西南山地以及川西高原的南部区域是干旱高风险区,大部分区域可达极重风险,盆地以盆中为干旱风险高发区。
Based on the daily meteorological data of 135 meteorological stations in Sichuan Province from 1961 to 2014 and wheat observation data from 29 agricultural meteorological stations, the index of water profit and loss was selected as drought assessment index. The average annual growth rates of the seven major growing regions of Sichuan wheat Spatial and Temporal Variations of Drought and Their Risk Distribution. The results showed that the average number of occurrences of drought stations in each growth period of wheat was the highest in mountainous areas in southwestern Sichuan, with the average value of 0.9 or more in many years, which could be described as the ten-year drought. The variation trend of times of drought stations in all districts is not obvious. The frequency of drought in booting stage-heading stage was higher in fertility stage, followed by that in jointing-booting stage, and lowest in heading-milk stage. From the spatial distribution characteristics of drought frequency, the southwest Sichuan is the region with the highest frequency of mild drought. The frequency of the moderate and severe drought in the western Sichuan Plateau is higher than that in the other regions, and only in the basin and in the western part of the basin Drought frequency is relatively high. The risk distribution of wheat drought is that the southwest Sichuan Basin and the southern area of the western Sichuan Plateau are high-risk areas of aridity, and most of the areas are at extremely high risk. The basin is characterized by high drought-risk areas in the basin.