白银市玉米春霜冻害精细化风险评估

Spring Frost Disaster of Corn in Baiyin:Refined Risk Assessment

基于玉米春霜冻害等级指标,建立地温与气温间的统计关系,拟合乡镇地温资料,进而对白银市玉米春霜冻致灾因子开展精细化风险评估。结果表明:春季白银市霜冻出现越晚,则霜冻强度越强,造成作物的受灾程度也越严重;研究期内地温与气温、区域站与本站温度之间相关性显著,拟合出乡镇地温资料可靠性较高;从各等级霜冻强度分布看,景泰西北部始终存在高值区,中部的白银、靖远海拔相对较低,加之地形因素,霜冻强度较弱。从概率分布看,会宁和景泰春季轻霜冻害发生概率较高,白银区和平川区主要以中霜冻害为主,而靖远重霜冻害出现概率较高。从风险指数看,白银市春霜冻害的高风险区主要在景泰西部和白银区,风险指数超过了0.32,会宁中北部相对较低,大部分乡镇风险指数在0.2左右。

Based on the indexes of spring frost damage grades of corn,the authors built the statisticalrelationship between ground temperature and air temperature,and fitted the ground temperature data oftownship,then carried out the refined risk assessment of spring frost disaster-causing factors of corn in Baiyin.The results showed that：the later the occurrence time of spring frost in Baiyin,the stronger the intensity offrost,and the more serious disaster degree the frost caused to crop; during the study period,there was asignificant correlation between ground temperature and air temperature,the temperature of regional station andlocal station,the high reliability of ground temperature in township was fitted; from the distribution of the wholefrost intensity grades,there was always a high value area in northwest Jingtai,because of relatively low altitudeand topographic factors,there was a weaker intensity of frost in Baiyin and Jingyuan; from the probabilitydistribution,the higher probability of spring light frost disaster appeared in Huining and Jingtai,the mediumfrost disaster mainly appeared in Baiyin and Pingchuan,however,the higher probability of heavy frost disasterappeared in Jingyuan; from the risk index,the high risk area of spring frost disaster in Baiyin was mainly inwestern Jingtai and Baiyin,where the risk index exceeded 0.32; the risk index in north central Huining wasrelatively low,and was about 0.2 in most of the township.