河北省冬小麦—夏玉米干旱灾害风险评估

RISK ASSESSMENT OF DROUGHT OF WINTER WHEAT AND SUMMER MAIZE IN HEBEI PROVINCE

关键词:  自然灾害  干旱  风险评估  信息扩散  作物水分亏缺指数  综合区划

Key words:  natural disasters  drought  risk assessment  information diffusion  crop water deficit index  comprehensive zoning

摘要:

目的 通过分析河北省冬小麦和夏玉米的干旱灾害风险的时空分布格局，从致灾因子危险性、承灾体暴露性、环境敏感性、防灾减灾能力4个因子出发确定10个指标，为河北省农业防旱抗灾工作提供科学支持。方法 文章基于自然灾害理论，利用2000—2018年河北省气象站点数据，计算水分亏缺指数，并通过建立农作物减产率和水分亏缺指数的关系来确定不同干旱等级的临界阈值，建立基于信息扩散理论的干旱危险性评估模型。利用遥感数据以及统计年鉴数据，建立承灾体暴露性模型、环境敏感性模型和防灾减灾能力模型，在此基础上，对河北省冬小麦和夏玉米不同生育阶段进行干旱灾害综合风险评估。结果 （1）将信息扩散模型应用于小样本事件中，弥补资料不足带来的缺陷，可对不同级别的干旱进行风险评估；（2）干旱发生程度以轻度干旱和中度干旱为主，发生严重干旱的概率极低，致灾因子是影响旱灾程度的关键因素；（3）冬小麦和夏玉米在不同生育阶段风险的空间分布是不均的，高风险区和中高风险区呈现零星点状分布，冀中和冀南综合风险比较高，防灾减灾能力在一定程度上缓解了旱灾对该区的影响力度，而对于冀东地区来说，承灾体的暴露性以及防灾减灾能力决定了旱灾对该区的影响力度。结论 因此，建立的冬小麦和夏玉米不同生育期干旱灾害风险评估模型可有效地识别农业旱灾高风险区，服务于农业生产实践，可为防灾减灾提供支持。

Abstract:

This research aims to analyze the spatial and temporal distribution pattern of drought disaster risk of winter wheat and summer maize in Hebei province, 10 indexes are determined from four factors which are risk of disaster causing factors, exposure of disaster bearing body, environmental sensitivity and disaster prevention and reduction ability, so as to provide scientific support for agricultural drought prevention and disaster relief work in Hebei province. Based on the theory of natural disasters, the crop water deficit index was calculated by using the data obtained from meteorological stations in Hebei province from 2000 to 2018, and the critical thresholds of different drought levels were determined by establishing the relationship between the crop yield reduction rate and the crop water deficit index, and then the drought risk assessment model was established based on the information diffusion theory. The remote sensing data and statistical yearbook data was used to establish hazard-bearing body exposure model, environmental sensitivity model, disaster prevention and mitigation capabilities model, and the comprehensive risk assessment of drought disasters was conducted at different growth stages of winter wheat and summer maize in Hebei province. The results showed that the information diffusion model was applied to small sample events to make up for the shortcomings caused by lack of data, as well as the risk assessment at different levels of drought could be evaluated. If the occurrence degree of drought was mainly mild and moderate drought, the probability of severe drought was very low, and the hazard factor was the key factor that affected the degree of drought. The spatial distribution of risk of winter wheat and summer maize at different growth stages was uneven, and high risk areas and medium and high risk areas showed a sporadic distribution. The comprehensive risk in central and southern Hebei was relatively high, and the ability of disaster prevention and mitigation could alleviate the impact of drought on some region. For eastern Hebei, the exposure of disaster bearing body and the ability of disaster prevention and mitigation determined the impact of drought risk on the region. Therefore, the drought risk assessment model of winter wheat and summer maize at different growth stages can be established effectively to identify high-risk areas of agricultural drought, serve the practice of agricultural production, and provide support for disaster prevention and mitigation.