两种常用的春玉米干旱等级指标在东北区域的适用性检验

Applicability Test of Two Common Indexes for Spring Maize Drought Grade in Northeast China

作物干旱等级农业气象指标是开展作物干旱监测、预警和评估的科学依据,其适用性关系到农业气象业务质量和防灾减灾效果。应用东北地区31个春玉米代表站1981 2012年逐日气象资料、土壤湿度资料、玉米生长发育观测资料及产量资料,对东北地区春玉米不同生育阶段土壤相对湿度和水分亏缺指数干旱等级指标进行应用效果检验,比较适用性差异,并利用黑龙江省2013—2016年的资料进行干旱实例分析。结果表明,土壤湿度和水分亏缺指数干旱等级指标均适用于东北区域春玉米不同生长时段干旱识别,且有较好的一致性,两套指标判定的春玉米干旱等级完全相同的占75%左右,相同和基本相同的占95%左右。两套指标对历史和近年玉米干旱事件的判识效果都较好,土壤湿度指标和水分亏缺指数的干旱识别正确率分别在80%和75%以上,土壤湿度指标判定效果更好。两套指标在玉米生育前、中期适宜性略好于后期,在东北三省的应用效果要略好于内蒙古东部,部分干旱年份水分亏缺指数判定的灾情等级偏高,因此,当两套指标判定结果存在差异时,应以土壤相对湿度指标判定结果为准。

Agrometeorological indicator of crop drought grade is the scientific basis for crop drought monitoring, early warning and assessment, and its applicability is related to the quality of agricultural meteorological service and the effect of disaster prevention and mitigation. By using daily meteorological data, soil relative moisture data, spring maize growth and development observation data and maize yield data in 1981--2012 from 31 spring maize representative stations in Northeast China, the application effect of soil moistrue and water deficit index indicators for spring maize drought grade are tested, and their applicability differences are compared. By using the data from 2013 to 2016 in Heilongjiang Province, an example is an- alyzed. The results show that the soil moisture indicator and the water deficit index indicator are suitable for determining spring maize drought grades in different growth stages in Northeast China and they have good consistency. The same proportion of the two sets of indicators to determine the drought grade of sp- ing maize is about 75%. The same and basically same proportion is about 95%. Identification effect of the two sets of indicators are good on the historic and recent maize drought events, the accuracy of drought identification by soil moisture indicator and water deficit index are above 80% and 75% respectively, and the identification effect of soil moisture indicator is better. The suitability of the two sets of indicators in early and mid stage is slightly better than that in later stage. The application effect in three provinces in Northeast China is better than that in East of Inner Mongolia. In some drought years, the drought grade determined by water deficit index is higher, so when the results determined by the two sets of indicators are different, it should be based on the results of the soil relative moisture indicator.