摘要
长江流域出现致洪大暴雨与青藏高原上中尺度对流系统(MCSs)的东移密切相关。为了寻找MCSs移动和传播的规律,我们将MCSs的移动路径与其中心附近一定范围内的环境物理量场之间建立联系,构造出MCSs东移空间数据挖掘数据库。在这个数据库中,包含由9个环境物理量生成的18个属性项,除此,还包括由MCSs本身的空间特征量构成的5个属性项,即TBB强度、面积、地理位置、形状等,共计23个属性项。利用1998年6月至8月日本地球静止气象卫星(GMS)的青藏高原逐时红外遥感云图计算出的云顶黑体辐射温度(TBB)及青藏高原高分辨率有限区域数值分析预报值系统(HLAFS)环境场物理量数据,构造出上述空间数据挖掘数据库,运用空间相关分析技术对其进行约简,结果表明:在高度(H)、温度(T)、涡度(VOR)、散度(DIV)、水汽通量散度(IFVQ)、垂直速度(W)、假相当位温(θse)、K指数(K)、相对湿度(RH)等9个因素中,高度、涡度、散度、水汽通量散度、垂直速度及k指数6个因素相对独立;而温度(T)、假相当位温(θse)、相对湿度(RH)之间相关性较强,而且与高度等其它6个因素密切相关。根据数据库约简原则,可将温度(T)、假相当位温(θse)、相对湿度(RH)3个因素生成的6个属性项从数据库中删除,以便提高数据挖掘效率。
Several heavy rainfalls in Changjiang River Basin are considered to be highly related to the moving out of the mesoscale convective systems (MCSs) from the Tibetan Plateau to the east. To discover the rules of MCSs moving and promulgating, the relationship is established between moving trace of MCSs and its surrounded environmental physical field. And the database of spatial data mining is designed to the MCSs moving out to east from Tibetan Plateau. In the database of spatial data mining, there are not only 18 attribute terms brought by 9 environmental physical variables, but also some spatial character terms of MCSs, such as area, position, shape, and intension of MCSs. By analyzing the cloud-top' s temperature of black body (TBB) from the hourly GMS infrared images and the data of the High Resolution Limited Area Forecast System (HLAFS) of the Tibetan Plateau from June to August in 1998, the database of spatial data mining is built. It is studied that the database is reduced using correlation analytical method. The study reveals that the height (H), the vortex (VOR), the divergent (DIV), the water vapor flux divergent(IFVQ), the wind aplomb speed(W) and the K-index are relatively independent parameters among the nine environment physical variables around the MCSs, while the temperature (T), the fake correspond potential temperature (θse) and the relative humidity(RH) are highly related to each other,as well as to the Height. Hence, we suggest that the tempera-ture(T), the fake correspond potential temperature(θse) and the relative humidity(RH) be not considered for the construction of the data base of MCSs spatial data mining, so as to increase the efficiency of the MCSs spatial data mining and to reduce the data redundancy.
出处
《地理科学进展》
CSCD
北大核心
2004年第3期27-33,i002,i003,共9页
Progress in Geography
基金
香港特区政府研究资助项目(CUHK4132/99H).
关键词
青藏高原
中尺度对流系统(MCSs)
红外遥感
空间数据挖掘
相关分析法
Tibetan Plateau
mesoscale convective systems (MCSs)
infrared remote sensing
spatial data mining
correlation analytical method
