新疆喀什地区冰雹气候特征及大气环境背景分析

利用新疆喀什地区13个县(市)1962-2012年51 a来冰雹天气时序资料及喀什市探空站资料,采用统计、M-K检验等方法进行冰雹时空分布特征和环境条件分析.结果表明:喀什地区冰雹日数总体呈逐年增加的趋势,年内冰雹天气表现出显著的年代振荡特征;空间分布差异较大,大致为北多南少.局地性冰雹明显多于系统性冰雹.冰雹发生的季节分布呈单峰型,高发期在5-7 月.冰雹发生前垂直风切变、湿对流能量及整层水汽积分必须同时满足一定条件,缺一不可;0 ℃层高度和-20℃层高度之间的厚度越小越有利于产生大雹.主要天气型为中亚低槽(涡)、不稳定短波槽和南北槽叠加3类,中亚低槽(涡)和不稳定短波槽过境是触发系统性冰雹、局地性冰雹的重要影响系统.     

边界层对青藏高原东北边坡地区一次冰雹天气影响的数值诊断分析

通过使用WRF V3.4模式,对发生在青藏高原东北边缘地区的一次区域性严重冰雹灾害事件从边界层进行了分析,研究发现这次灾害是由于前期能量积蓄和地形等原因导致分配不均匀,进而引发次级环流,配合天气尺度环流系统,造成了这一历时短、强度强、突发性强、局地性强和多灾种并发的特大灾害性天气事件;强天气过程发生时的对流边界层高度远小于平均状况,但是前期的最大对流边界层高度呈逐步增厚的特征,说明在进行能量积蓄,且边界层对强天气过程有显著影响;潜热和感热通量在发生前远超过平均状况,而其中又以感热通量差异最大,说明热力作用对对流天气过程占有主导地位;在近地面的条件不稳定层结之上存在一个绝对稳定层结,它的厚度逐渐减小,绝对稳定层结之上的条件不稳定层结的假相当位温减温率在13:00峰值达到0.88 K·(100m)-1,而水平位温梯度也基本在这时达到最大;边界层的摩擦速度在天气过程发生前后均呈现出了显著增大,这可能是由于湍流动量和中尺度动量输送异常造成的。     

TWR-01小型天气雷达在人工防雹作业中的应用

TWR-01型天气雷达是2008年开始在内蒙古自治区10个新一代天气雷达站网不能覆盖的旗县投入使用的,为旗县更加科学的实施人影作业提供了较好的依据。而旗县TWR-01型天气雷达的使用在起步阶段,研究应用较少,对TWR-01型天气雷达在人工防雹作业中的应用进行了探讨,总结近2年的使用经验,以对今后旗县TWR-01型天气雷达的使用提供参考价值。     

望谟县冰雹危害特征分析及预防对策

利用望谟县冰雹观察资料( 1967年～2017年),对望谟县近51年冰雹的变化特征、持续时间、入侵路径等特征进行分析,得出如下结论,即近51年望谟县冰雹发生总计35 次,冰雹主要发生在4～5 月;冰雹出现时间主要在14:00 时至18:00 时,出现的次数为12次,次之在18：00时至20:00 时,出现的次数为9次;冰雹持续时间多数在1分钟左右,平均时间低于8分钟;入侵路径主要有自西向东、 自西向东南、自西向东北三条路径。建议每年2月～5月的每日14:00～22:00时段,加强冰雹预防,在冰雹入侵路径上布设防治冰雹的防雹站。     

Lint Yield Compensatory Response to Main Stem Node Removal in Upland Cotton (Gossypium hirsutum)

Hail storm damage to the cotton (Gossypium hirsutum L.) plants can destroy vegetative and reproductive structures, modify canopy architecture and impact lint yield. Field studies were conducted at University of Arizona Maricopa Agricultural Center in 2011, 2012 and 2013 to examine cotton plant architecture changes and compensatory growth in response to removal treatments of uppermost nodes on main stem (terminal bud removal, 2 node removal and 4 node removal) as simulation of hail damage at the node 2, 4, 8, 12, 16 and 24 growth stages. Main stem node removal caused significant decrease in leaf area and biomass, especially at early growth stages. However, significant lint yield reduction only occurred by removing 2 nodes at the node 4 stage and removing 4 nodes at the node 8 stage in 2011, removing terminal bud at the node 12 stage in 2012 and removing terminal bud, 2 nodes and 4 nodes at the node 8 stage in 2013. The lint yield reduction did not exceed 13 % in all three growing seasons. Yield loss due to main stem node removal was mainly compensated by increased boll number on the vegetative branches at early growth stages and on fruiting branches at late growth stages. Yield compensation from vegetative branches increased with number of main stem nodes removed. This study suggests that the cotton crop has a strong compensatory ability to plant structure damage due to its indeterminate growth and longer growing season in the region.     

Effects of Hail on Evapotranspiration and Plant Temperature of Maize

The effect of natural and artificial hail on the evapotranspiration of maize (Zea mays L.) was studied. In 1998, observations were made after a natural hailstorm, while in 1999 hail was simulated by lacerating the leaves parallel with the leaf veins. Plants of one treatment were grown in a lysimeter. In addition to evapotranspiration, measurements were also made on plant temperature. Among physiological processes, the modifications occurring in evapotranspiration could be divided into two distinct phases. On the days immediately following the damage the raised plant temperature caused by the wounds indicated a reduction in evapotranspiration leading to less efficient plant cooling. Later, in both the natural and artificial hail treatments, changes in evapotranspiration depended on the weather. The changes in evapotranspiration and plant temperature after natural and artificial hail injury were similar in nature. The yield loss was less than 10 %, in agreement with data in the literature on the effect of simulated hail injury. However, it can be expected that further study of simulated hail injuries will lead to a better understanding of the changes in plant water balance caused by hail.     

Effects of Simulated Hail Damage on the Yield of Forage Maize

Hail damage was simulated with defoliation, leaf tearing and damage to ears and stems, applied at five stages and three levels of intensity on forage maize grown in Belgium. Leaf tearing alone had little effect on total dry matter yield. Decrease of yield was the highest when treatments were applied around tasseling-anthesis. Effects on total dry matter content were small.     

利用环境减灾卫星遥感监测冰雹灾害初探

【目的】寻求一个高效、准确的冰雹灾害遥感监测方法,为黑龙江省开展生态灾害的卫星遥感监测提供技术参考。【方法】针对2011-08-18黑龙江省木兰县一次冰雹灾害的个例,结合天气实况和雷达资料,利用从环境减灾卫星获得的遥感数据（2009-2011年）,分析了冰雹灾害前后归一化植被指数（NDVI）的变化,对遭受冰雹灾害区域进行了遥感监测,并对监测结果进行了检验。【结果】植物遭受冰雹灾害后的一段时间内,NDVI出现异常下降的现象,与未遭受冰雹灾害的区域差别明显,说明利用NDVI来判别遭受冰雹灾害的区域是可行的。遥感监测结果显示,此次遭受冰雹灾害的区域为木兰县西南部（东经127°38′～127°55′,北纬45°55′～46°06′）,受灾总面积为82.17 km²。监测结果表明,遥感监测冰雹灾害的准确率平均可达86.67%。【结论】利用环境减灾卫星对冰雹灾害进行遥感监测和灾害等级评估是可行的。     

烟田防雹网架设技术及应用前景

阐述了烟田防雹网的架设技术,并对该技术的经济效益及推广应用前景进行分析,以期为烤烟种植中减少冰雹灾害损失提供参考。     

玉溪市雹灾发生规律及降雹临界参数特征分析

分析玉溪市雹灾的发生规律,以为科学开展防雹作业提供重要依据。对回波进行跟踪分析,了解回波的发展规律,提取降雹时的临界参数。指挥人员可以根据降雹的临界参数值指挥作业,保证在作业时以最少的成本创造最大的经济效益,达到最好的作业效果。