甘肃省冬小麦干旱时空分布特征研究

Temporal and Spatial Distribution Characteristics of Winter Wheat Drought in Gansu Province

摘要: 为了分析甘肃省冬小麦干旱时空分布的主要特征，本文用中国地面气候资料日值数据集(V3.0)，全国地理信息资源目录服务系统中的甘肃局部矢量地图数据，通过水分亏缺指数公式、作物水分需求量公式、干旱频率公式、FAO Penman-Monteith公式和局部多项式插值法，对甘肃省冬小麦种植区的水分亏缺指数以及干旱灾害等级进行时间和空间上的分布进行分析，结果表明：1) 甘肃省冬小麦的水分亏缺指数较高，相比较于其他省份的指数，大约会高出10%到20%，这说明甘肃省的冬小麦对水分的需求比较大，自然的大气降水量基本无法满足甘肃冬小麦的生长发育，而水分的供给不足会直接导致最终小麦的产量不足。2) 在时间上，3个时期的水分亏缺指数(CWDI)都比较平缓，年变化并不大，指数大小为全生育期 > 乳熟–成熟期 > 拔节–孕穗期，拔节期、乳熟期、全生育期的年水分亏缺指数分别在68%、55%、70%附近摆动，而最大值分别为91%、79%、81%，除了在175~1991年和2010~2016年CWDI有一个明显的下降，其余年份几乎没有什么波动，而最近几年，水分亏缺指数处于下降趋势，这说明甘肃省近些年的降水量是在增加的。3) 在空间上，干旱频率大小为全生育期 > 乳熟–成熟期 > 拔节–孕穗期，在拔节期、乳熟期、全生育期的严重干旱概率分别为27%~95%、40%~91%、70%~95%，重旱概率分别为5%~51%、5%~27%、4%~23%，中旱概率分别为0%~25%、3%~22%、1%~6%，不同地区的干旱等级以及出现的概率有一个较大的差距，整个研究区域呈现中央干旱较少较弱，逐渐向四周扩散的局面，而四周又以文县、武都、环县最为严重。

Abstract: In order to analyze the main characteristics of temporal and spatial distribution of winter wheat drought in Gansu Province, the Chinese surface climate data daily data set (V3.0) and the local vector map data of Gansu Province in the National Geographic Information Resource Catalogue Service System were used. The Temporal and spatial distribution of water deficit index (CWDI) and drought disaster grade in winter wheat growing areas of Gansu Province were analyzed by using the CWDI formula, crop water demand formula, drought frequency formula, FAO Penman-Monteith formula and local polynomial interpolation method. The results showed that: 1) The water deficit index of winter wheat in Gansu Province was higher, about 10% to 20% higher than that of other provinces, which indicated that the demand for water of winter wheat in Gansu Province was relatively large, and the natural atmospheric precipitation could not meet the growth and development of wheat in Gansu, and the insufficient supply of water would directly lead to insufficient yield of wheat. 2) Temporally, the water deficit index (CWDI) of the three stages is relatively flat, and the annual change is not large. The index is in the order of the whole growth period > milk-maturity period > jointing-booting period. The annual CWDI of jointing stage, milk-maturity stage and the whole growth period swings around 68%, 55% and 70%, respectively, and the maximum values are 91%, 79% and 81%, respectively. Except for a significant decline in CWDI in 175~1991 and 2010~2016, there is almost no fluctuation in other years, while in recent years, the water deficit index is in a downward trend, which indicates that the precipitation in Gansu Province is increasing in recent years. 3) The spatial distribution of drought frequency is in the order of whole growth period > milky mature-mature period > jointing-booting period. The probability of severe drought at jointing stage, milky maturity stage and whole growth period is 27%~95%, 40%~91%, 70%~95% respec-tively, and the probability of severe drought is 5%~51%, 5%~27%, 4% The probability of moder-ate drought was 0%~25%, 3%~22% and 1%~6%, respectively. There was a big difference in the grade and probability of drought in different areas. The drought in the central area was less and weaker, and gradually spread to the surrounding areas, while the most serious drought was in Wenxian, Wudu and Huanxian.