基于状态空间模型的气候变化与中国粮食安全动态关系研究

RELATIONSHIP BETWEEN CHINA'S FOOD SECURITY AND CLIMATE CHANGE BASED ON TIME VARYING PARAMETER MODEL

关键词:  状态空间模型 气候变化 中国粮食安全 动态效应

Key words:  climate change  food security  dynamic effects  state space model

摘要:

粮食安全问题关乎国家的长治久安， 2014年中央经济工作会议将“切实保障国家粮食安全”提升为六大经济任务中的首要一项。该文着重探究气候变化对我国粮食安全的动态影响，以稻谷、小麦、玉米3种主要粮食作物产量分别作为研究因变量，从气候变化与要素投入两方面选取指标作为自变量。以1978~2012年的面板数据为样本，通过基于卡尔曼滤波理论的状态空间模型对我国气候变化与粮食安全的动态关系进行了研究之后发现：气候变化、物质要素投入与粮食产量之间存在一种随时间不断变化的长期动态均衡关系，即变参数关系。气温方面，我国主要粮食产区气温普遍升高，气温上升对玉米的负面影响尤其明显； 降水方面，稻谷主产区降水减少、玉米主产区降水则呈现增加的情况，结合水利设施考虑，稻谷主产区应注重预防干旱灾害，玉米主产区则要注意预防洪涝的影响； 日照方面，全国粮食主产区日照时数减少，给粮食产量带来一定积极影响。气候变化对各种作物的影响不同，总体来看，稻谷、小麦的适应性好于玉米。为了应对气候变化、保障我国粮食安全，该文提出以下参考措施：包括构建气象监测分析预测一体化的决策系统、调整农作物布局和结构、调整激励体系、建立气象灾害保险。

Abstract:

Food security is closely related to the long-term stability of our country, which is promoted as one of the six primary tasks in the Central Economic Affairs Meeting lists in 2014. This paper mainly discussed the dynamic effects of climate change on food security, ie., taking the yields of rice, wheat and corn as dependent variables and climate changes and factor inputs as explanatory variables. We estimated the dynamic relation between China's climate change and food security based on a state space model and panel dataset from 1978 to 2012. The results showed that there was a long-time dynamic equilibrium relationship among climate change, materials input and food production. During the study period, it detected the following trends regarding temperature, precipitation and sunshine. Temperature generally rising in China's major grain producing areas had a significant negative effect on corn yields. Precipitation decreased in main rice producing areas and increased in main corn producing areas. Therefore, the main rice producing areas should focus on preventing drought, while the main corn producing areas should pay more attention to preventing floods. Sunshine duration decreased nation-widely had a positive impact on food yields. Generally, climate change had different influences on different crops. The adaptability of rice and wheat was better than corn. Based on these findings, the following measures were proposed to enhance the food security of China: to establish an integrated analysis and forecasting meteorological monitoring system, to adjust the layout and structure of crops production, to improve the incentive mechanism, and to establish meteorological disaster insurance system.