白银市玉米春霜冻害精细化风险评估

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。

Spring Frost Disaster of Corn in Baiyin: Refined Risk Assessment

Based on the indexes of spring frost damage grades of corn, the authors built the statistical relationship between ground temperature and air temperature, and fitted the ground temperature data of township, 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 of frost, and the more serious disaster degree the frost caused to crop; during the study period, there was a significant correlation between ground temperature and air temperature, the temperature of regional station and local station, the high reliability of ground temperature in township was fitted; from the distribution of the whole frost intensity grades, there was always a high value area in northwest Jingtai, because of relatively low altitude and topographic factors, there was a weaker intensity of frost in Baiyin and Jingyuan; from the probability distribution, the higher probability of spring light frost disaster appeared in Huining and Jingtai, the medium frost disaster mainly appeared in Baiyin and Pingchuan, however, the higher probability of heavy frost disaster appeared in Jingyuan; from the risk index, the high risk area of spring frost disaster in Baiyin was mainly in western Jingtai and Baiyin, where the risk index exceeded 0.32; the risk index in north central Huining was relatively low, and was about 0.2 in most of the township.