1949—2016年中国旱灾规律及其对粮食产量的影响

Characteristics of drought disaster and its impact on grain production in China from 1949 to 2016

关键词:  干旱灾害  灾害指数  粮食产量  中国

Key words:  drought disaster  disaster index  grain production  China

摘要:

目的 探究1949—2016年中国干旱灾害长时间序列时空变化特征及其对粮食生产的影响，为我国农业干旱灾害预警体系和保障粮食产量提供参考。方法 基于Python语言获取1949年以来中国各省、市农业自然灾害和粮食生产数据，然后利用Pearson相关性统计分析、回归分析、自然断点分级法、GIS平台和R语言定性和定量地探讨干旱灾害对粮食生产的影响，阐述我国农业旱灾变化规律和粮食安全态势，探讨农业旱灾对粮食生产的影响。结果 ①农业干旱灾害呈现明显周期性波动，干旱轻重灾情交替出现，1949—1970年为波动阶段，1971—2000年为波动上升阶段，2001—2016年为波动下降阶段，发生特大干旱和严重干旱的年份所占比重较大；②农业干旱在空间上呈“北重南轻、中东部重西部轻”的格局。山东受灾最重，灾损高达208.2万hm²，西藏最轻，灾损为2163.53 hm²；③粮食产量和粮食单产总体呈稳步增长态势，波动幅度较平缓，二者受旱灾影响程度较大，粮食产量和粮食单产的年变化率均与干旱受灾率、成灾率、灾害强度指数、受灾率异常指数和成灾率异常指数等指标显著负相关，其中以受灾率异常指数和成灾率异常指数对粮食生产的影响更为显著，且受灾率异常指数的影响最为显著；④粮食产量的多少和受灾面积的大小在空间上具有相关性，粮食单产与干旱受灾面积呈负相关。结论 干旱灾害制约我国粮食生产，各农业干旱灾害指标对粮食灾损的解释力较强，对粮食产量估测具有参考作用。建立和完善农业灾害预警体系，可以提高应对农业干旱灾害的能力，进一步为粮食进出口提供指导意见。此外，干旱灾害仅是影响粮食产量的一个方面，农业科技水平、社会经济制度、农业政策等也对其具有不容小觑的影响。

Abstract:

Purpose China is a country with frequent natural disasters，and drought disaster is the most serious one among them. Grain production is related to the national economy and people’s livelihood，which is an important foundation for maintaining social stability. Agricultural drought disasters have a significant impact on grain production. It is of great significance for estimating grain production，realizing China’s social and economic sustainable development，and solving China’s food security problems that studying the evolution characteristics of drought disasters and the law of food disasters.Method In this paper，we obtained agricultural natural disasters and grain production data from various provinces and municipalities in China between 1949 and 2016 based on Python language. Then，we discussed the impact of drought disasters on food production qualitatively and quantitatively with the methods of Pearson correlation statistical analysis，regression analysis，and natural breakpoint grading method，with the assistance of GIS platform and R language. We explained the changes of agricultural drought and food security in China，and explored the impact of agricultural drought on food production.Result The results show that:①Agricultural drought disasters exhibit obvious cyclical fluctuations，during which light and heavy disasters alternate. The value of affected area was fluctuated from 1949 to 1970. It increased slightly from 1971 to 2000 while it decreased slightly from 2001 to 2016. The proportion of years with extreme drought and severe drought is large.②The agricultural drought is spatially characterized by the pattern of “the north is more serious than the south and the central and eastern regions are more serious than the western regions”. Shandong is the worst affected which the damage amounted to 2.082 millio n hm²，and Tibet is the lightest which the damage was 2 163.53 hm².③The grain output and grain yield showed a steady growth trend，and the fluctuation range was relatively flat，but the two were affected by the drought. The annual gradient of total grain yield and grain per mu are significantly negatively correlated with indicators such as disaster-affected/suffering area rates，the ratio of disaster affected to suffering areas and anomaly indices of disaster-affected/suffering area rates，among which the impact of anomaly indices of disaster-affected/suffering area rates on grain production is the more significant，and anomaly indices of disaster-affected area rates is the most significant.④The amount of food produced and the size of the affected area are spatially correlated. The grain yield is negatively correlated with the area affected by drought.Conclusion Drought has a great negative impact on China’s grain production. The indicators of agricultural drought disasters have a strong explanatory power for food disasters，which have a reference role in estimating grain production. Establishing and improving the agricultural disaster prevention and mitigation system can improve the ability to cope with agricultural drought disasters，and further provide guidance for grain import and export. Nevertheless，drought disasters are the only one aspect that affects grain production. Agricultural science and technology，social and economic systems，agricultural policies，etc. also have an impact on grain production.