【作者】 张海玲；

【导师】 益建芳；

【作者基本信息】 华东师范大学 ， 地图学与地理信息系统， 2005， 硕士

【摘要】 暴雨是一种常见的天气过程,持续性大暴雨往往会引起洪涝灾害,给人民的生命财产造成严重损失,因此,对于暴雨产生和发展的研究十分重要。由于影响暴雨形成的环境场因子众多,关系复杂,如何确定环境场因子与暴雨之间的关系?各个因子之间如何关联才会产生暴雨?产生的暴雨量有多大?每个环境物理量在什么条件下起作用?针对诸如此类的问题,采用传统的、定性的天气图模型及数值预报方法很难有效地解决。而空间数据挖掘是近年来迅速发展起来的面向应用的新技术,应用不同学科交叉解决气象学中的难点问题是一次有重要意义的尝试。为此,本文利用国家卫星气象中心提供的1998～2000年6～8月T106数值预报产品及相应时段长江流域中下游地区(110°E～123°E,24°N～34°N)各测站的日降水量数据,在建立日降水量及环境物理量场空间数据库的基础上,通过提取暴雨中心周边环境物理量场的特征值,运用空间数据挖掘中的决策树方法建立了暴雨中心暴雨量与周边环境物理量场之间的确定性关系。 本文所采用的是与暴雨有关的环境物理量场包括位势高度、温度、涡度、散度、水汽通量散度、地面气压、假相当位温、K指数、相对湿度等9个物理量场的数据,水平分辨率为1°(经)×1°(纬),时间分辨率为24小时,研究层次为500hPa。论文首先运用等值线作图法分析了环境物理量场空间分布特征与暴雨中心暴雨量之间的关系,结果表明,暴雨中心暴雨量与各环境物理量场之间的对应关系并不明显,且不确定性的关系居多。为此,在上述分析的基础上,我们采用决策树方法来揭示周边环境物理量场对暴雨中心暴雨量的影响机制。研究结果表明,暴雨发生地不同,影响暴雨的环境物理量场不同,并且暴雨中心周边不同外延范围内,对影响暴雨产生的环境物理量场也不同。这一结论为区域暴雨预报中环境物理量场的选择提供了重要的科学依据,且对于提高区域暴雨预报的准确性具有重要的理论意义和实际应用价值。更多还原

【Abstract】 Rainstorm is a kind of common weather processes, consistent intensity rainstorm usually arises flood disaster, even leads to severe loss to the people’s lives and property. Therefore, it is very important to study the producing and developing of the rainstorm. On the other hand, the relationship between environmental physical field values and the center of rainstorm is complex, consequently, it is difficult to solve such problems, for example, how to develop the relationship between environmental physical field values and rainstorm? How to form rainstorm? How much rainstorm will be produced? When will each environmental physical field value impact the amount of rainstorm? To these problems, traditional methods, such as weather graph models and numeric weather forecasting methods, are limited. However, spatial data mining is a new application technology and develops quickly in recent years. Therefore, it is a great meaning to solve difficult problems in meteorology using deferent knowledge. In this project, T106 data and daily rainfall data in Yangtze River (110° E~ 123°E, 24° N~34°N) Basin are used from June to August between years of 1998 to 2000. Based on these, the daily rainfall database and environmental physical field values database are developed. And, the feature values of environmental physical field are abstracted and decision tree is applied to set up the relationship between rainfall of rainstorm center and environmental physical field values.In this paper, nine parameters, including geopotential height, temperature, vorticity, divergency, relative water vapor flux divergence, pressure on the ground level, 9 se, K index and relative humidity at the level of 500hPa, are used to study the relationship between rainstorm and environmental physical field values. Among these data, the spatial resolution is 1°lat x1° long and time resolution is twenty four-hour. Based on these, the spatial distribution of each environmental physical field value and rainfall in study area is obtained to discuss the relationship between them. The results indicate that the relationship is undistinguishable and uncertain. Consequently, decision tree is used to reveal the basic theory of causing rainstorm. The results show that it is different of environmental physical field values influencing rainstorm in different area. And, environmental physical field values are also different around rainstorm center in different distance. Therefore, it has great meaning in choosing environmental field factors for regional disaster weather forecasting.更多还原