辽宁省玉米旱灾时空分布特征及综合风险评价

以辽宁省气象数据、空间数据和田间管理数据集为基础，首先，依据自然灾害风险形成理论，从危险性、脆弱性、暴露性和防灾减灾能力四因子入手，选择10个副指标，构建辽宁省玉米旱灾综合风险评价指标体系，并利用组合加权法和GIS空间分析方法，确定其权重及区域化。利用自然灾害风险指数法和加权综合评价方法，建立辽宁省玉米旱灾综合风险评价模型，并进行了辽宁省玉米旱灾时空分布特征分析及综合风险评价研究。结果表明：（1）自1960年以来，研究区干旱频率总体呈上升趋势，尤其2010年以后有明显增加态势。其中1970-1979年间干旱发生频率较低，2010-2019年间干旱频率最高。不管是月尺度、季节尺度、生长季尺度还是年际尺度，辽宁省西北部干旱频率普遍较高，而东南部干旱频率较低。干旱强度呈现从辽宁省中部地区向东西地区两个方向递减的趋势，高值出现在辽宁省中部的阜新、锦州、铁岭、辽阳、盘锦、鞍山、营口和大连等地。干旱历时从辽宁省东部向西部区域递减的趋势，其中高值出现在铁岭北部、盘锦、鞍山、营口和丹东南部等地，低值分布在朝阳西南部、葫芦岛西北部、本溪西部和丹东等地。（2）从4个因子角度来说，辽宁省朝阳西部和葫芦岛西北部玉米旱灾危险性指数较低以外其他区域玉米旱灾危险性指数均较高。然而，辽宁省西北玉米主产区玉米旱灾脆弱性指数和暴露性指数均较高，且防灾减灾能力较低。当4个因子加权综合评价时，辽宁省西北部玉米旱灾综合风险呈现较高的现象。研究结果可为保障辽宁省粮食安全及制定防灾减灾政策提供理论依据和科学指导。

Spatio-temporal distribution characteristics and comprehensive risk assessment of maize drought disaster in Liaoning Province

First, according to the theory of natural disaster risk formation, starting with the four factors of hazard, vulnerability, exposure and emergency response & recover capability, 10 sub-index were selected to establish the comprehensive risk evaluation index system of maize drought in Liaoning Province, based on meteorological data, spatial data and field management data. Second, the combined weighting method was used to determine the weight of each index in the evaluation index system, and each index was spatially processed according to the GIS space analysis methods. Finally, the natural disaster risk index method and weighted comprehensive evaluation method were used to establish the comprehensive risk evaluation model of maize drought in Liaoning Province. At the same time, based on the evaluation model, this paper analyzed the temporal and spatial distribution characteristics of maize drought in Liaoning Province, and further studied the comprehensive risk evaluation of maize in Liaoning Province. The results showed that:(1) The drought frequency in the study area has been increasing since 1960, especially after 2010. Among them, the frequency of drought in Liaoning Province was low from 1970 to 1979, but reached the highest from 2010 to 2019. No matter what the research scale (monthly scale, seasonal scale, growing season scale or inter annual scale) it was,the drought frequency was higher in the northwest of Liaoning Province, but lower in the southeast. The drought intensity of Liaoning Province had a decreasing trend from the middle to the East and West, and areas with high drought intensity were mainly concentrated in the middle of Liaoning Province (eg.Fuxin, Jinzhou, Tieling, Liaoyang, Panjin, Anshan, Yingkou and Dalian). The duration of drought in Liaoning province gradually decreased from east to west, and areas with high drought duration mainly appeared in the north of Tieling, Panjin, Anshan, Yingkou and the south of Dandong, while areas with low drought duration mainly appeared in the southwest of Chaoyang, the northwest of Huludao, the west of Benxi and Dandong. (2) From the perspective of four factors of drought disaster hazard, vulnerability, exposure and emergency response & recover capability, except that the drought hazard indexes of maize in the west of Chaoyang and the northwest of Huludao were low, the drought hazard indexes of maize in other regions were high in Liaoning Province. However, as the main maize producing area in Liaoning Province, the northwest of Liaoning Province had high vulnerability index and exposure index of drought disaster, but its emergency response & recover capability was relatively low. Therefore, under the weighted comprehensive evaluation of four factors, there was a high risk of drought disaster in the northwest of Liaoning Province. The research results can provide theoretical basis and scientific guidance for the formulation of policy on agricultural disaster prevention and mitigation in Liaoning Province.