基于农业灾情我国粮食主产区的干旱特征及其与环流指数的联系

CHARACTERISTICS OF DROUGHT IN CHINA'S MIAN GRAIN PRODUCTION AREAS BASED ON AGRICUTAL DISASTER CONDITIONS AND ITS RELATION TO CIRCULATION INDICES

关键词:  粮食主产省份  农业干旱受灾率  H-P滤波  干旱指数  大气—海洋环流指数

Key words:  grain producing provinces  agricultural drought-affected rate  H-P filtering  drought indices  atmospheric-ocean circulation indices

摘要:

目的 构建灾情统计数据与干旱指数间的数量关系有利于量化旱灾对气候变化的响应。方法 文章针对1980—2019年我国13个粮食主产区的农业干旱受灾率，通过H-P滤波从中提取了气候灾损。基于标准化降水蒸散指数计算的区域干旱强度和局部干旱强度，构建了气候灾损对不同月份干旱的响应关系，并探求了关键致灾因子与大尺度大气—海洋环流指数的可能联系。结果 （1）近10年，研究区的气候灾损呈现出较低强度；（2）研究区的轻度及以上干旱年景易发生在ENSO暖事件年份；（3）气候灾损与区域干旱强度的线性关系更为显著，其相关分析表明研究区夏季干旱的致灾性更高，其中7月份为多数省份的旱灾影响关键期；在河南、山东、安徽、江苏、湖北、吉林和辽宁，近10年关键期的干旱强度呈现上升趋势；（4）研究区关键期的区域干旱强度均存在着2~3年的振荡主周期；（5）前期环流指数构建的多元线性模型对关键期的干旱强度有一定的模拟能力，特别是Nino海温、南方涛动、北极涛动等因子被筛选为关键前兆信号。结论 该研究明确了我国粮食主产区农业旱情的关键致灾因子及其与环流信号的联系，为区域干旱监测及预警提供了科学依据。

Abstract:

Building the quantitative relationship between disaster statistics and drought indices is beneficial for quantifying the response of drought disaster to climatic changes. Aiming the agricultural drought-affected rate in 13 grain producing provinces from 1980 to 2019, the climatic disaster losses was extracted by using H-P filtering. Based on the calculation of regional drought intensity and partial drought intensity with standardized precipitation evapotranspiration index, the response relationship of climatic damage to drought in different months was constructed, and then the possible connection between key disaster-causing factors and large-scale atmospheric-ocean circulation indices was explored. The results were listed as follows. Firstly, the climatic disaster losses in the study area had shown the relatively lower intensity in the past 10 years. Secondly, the drought years with mild and over mild intensity in the study area likely occurred in the years of ENSO warm events. Thirdly, the linear relationship between climatic disaster losses and regional drought intensity was more significant, and the correlation analysis showed that the catastrophability of summer drought in the study area was higher, especially the July was identified as the critical drought-influencing period in most provinces. Fourthly, the drought intensity of critical period in Henan, Shandong, Anhui, Jiangsu, Hubei, Jilin, and Liaoning showed the upward trends during the past 10 years. Fifthly, regional drought intensity of critical period in the study area had a main oscillation period of 2~3a. Sixthly, the multivariate linear model constructed by the preliminary circulation indices had certain simulation ability for the drought intensity in critical periods, especially the factors such as Nino sea surface temperature, Southern Oscillation, and Arctic Oscillation had been screened as key precursor signals. In summary, this study clarifies the key disaster-causing factors of agricultural drought in China's main grain producing areas and their relationship with circulation signals, and provide scientific basis for regional drought monitoring and warning.