宝鸡市主要农作物冰雹灾害风险评估

Risk assessment of hail disaster for main crops in Baoji

冰雹灾害是宝鸡市面临的主要农业气象灾害之一,采用宝鸡市2016年的Landsat TM遥感影像,经过遥感解译得到宝鸡市主要农作物的空间分布图。根据宝鸡市1961—2016年55 a的降雹记录和防雹炮点分布资料,计算得到区域降雹强度、降雹频次和防雹能力值,以灾损数据确定主要农作物的承灾体敏感性指数。基于致灾因子危险性、承灾体暴露度及脆弱性三要素,采用综合评价法和自然间断分类法得出宝鸡市主要农作物的冰雹灾害风险分布图。结果表明:宝鸡市主要农作物的冰雹灾害风险等级以中级风险为主,占全部风险等级的43.5%,主要分布于千阳、凤县、岐山、扶风等地;次高风险区占25.2%,主要分布在陈仓及扶风;次低风险区占18.7%,分布于金台、眉县及太白零星散区;高风险区占9.8%,全部集中于陇县和麟游;低风险区占比最少,为2.8%,零星分布于凤县和扶风。应加强对冰雹灾害高风险区的防爆能力建设,调整防雹点分布和作物种植。

Background,aim,and scope Hail disaster is one of the main nature disasters that seriously affect the agriculture of Baoji area.In this paper,the risk of the hail disaster on crops of Baoji area were calculated by comprehensively evaluating the hazards of disaster-causing factors,exposure and vulnerability of disaster bodies.The adjustments of measurements against hail disaster were suggested.Materials and methods The spatial distribution of the main crops(wheat,corn,cotton)in Baoji area were obtained by interpreting Landsat TM images of the year 2016.The hail intensity,frequency and anti-disaster capacity were calculated on the hail records of Baoji Meteorological Bureau from 1961 to 2016.The disaster sensitivity index of main crops was determined according to the records of crops loss after hail disaster.Finally,the hazards of disaster-causing factors,exposure and vulnerability of disaster bodies were used to calculate the risk of the hail disaster on crops of Baoji area by comprehensive evaluation method and natural breaks classification method.Results Areas with medium risk account for 43.5%of the total area with crops and mainly distribute in Qianyang,Feng County,Qishan and Fufeng.Areas with sub-high risk account for 25.2%and mainly distribute in Chencang and Fufeng.Areas with sub-low risk account for 18.7%of the total area and mainly distribute in Jintai,Mei County and other sporadic areas.Areas with high risk account for 9.8%and all distribute in Long County and Linyou.Areas with low-risk account for the least proportion of 2.8%and scatter in Feng County and Fufeng.Discussion The vulnerability of crops to hail disaster were calculated according to the records of crops loss after hail disaster and the inquiry of planters,which can be further improved by plotting the vulnerability curve of crops through experiments.The risk grades of hail disaster on crops over Baoji area are the combined consequences of disaster intensity,anti-disaster capacity,types of crops and spatial distribution of crops.Conclusions The risk grade of hail disaster on crops,and sensitivity and vulnerability grade of crops to hail disaster in Baoji area are mainly medium.High risk area was mainly in Long county with the strongest hazards of hail disaster.High sensitivity and vulnerability areas were mainly in the cotton area of Fufeng,Fengxiang and Qishan.Recommendations and perspectives The monitoring and early warning of hail disaster in areas with high risk shall be strengthened,and the distribution of anti-hail stations and crop fields shall be adjusted according to the risk distribution of hail disaster.