中文摘要：

利用淮河流域内稠密的区域自动站资料、多普勒天气雷达组网资料、风云二号卫星双星观测资料及LAPS中尺度分析资料，对2007年7月8日淮河流域大暴雨过程的中尺度特征进行了综合分析，得出了一些有意义的结果。（1）这次降雨过程集中在淮河干流，呈现出强降水区稳定少动，高雨强出现频度大的特点，时空分布有利于形成大洪水，是一次典型的致洪大暴雨过程。（2）暴雨区与中低层的中尺度辐合扰动的形成、发展与移动密切相关，同时伴随着中尺度云团、雨团的强烈发展。中尺度雨带具有准静止性，且强度很强，这是此次暴雨过程的一个突出特点。（3）强降雨主要是在α尺度云带上不断生消发展的β中尺度云团，甚至更小的γ中尺度云团的生消合并造成的。它们大多生消于32～34°N、114～118°E范围内，β中尺度对流云团的生消、演变和移动与中β尺度雨团的强度和位置有较好的对应关系，强降水发生在中尺度对流云团合并发展和增强阶段。（4）暴雨区具有低层辐合高层辐散、高湿、正涡度和强烈上升运动的特征，它们加强中低层的动力抬升，促使斜压不稳定能量释放，引起垂直涡度的发展，产生很强的降水。强降雨发生时，对流层中层的比湿快速加大，而云中液态水则表现为骤然减小。

英文摘要：

A meso-scale characteristics analysis for the flash flood-inducing rainstorm over Huaihe River Basin in 2007 was performed with the rainfall data of high density automatic observation, Doppler-radar data, FY - 2 double satellite TBB and LAPS meso-scale analysis data etc. Some significant results are obtained. （ 1 ） The rainfall was localized mainly in the Huaihe River Basin. The rainfall intensity was strong and the rainfall area was stable. The temporal - spatial distribution of intensity was very favorable to occurrence of the flood. It was a typical Flash floodinducing rainstorm process. （2）The heavy rain area was correlated with the formation, development and movement of meso-scale convergence disturbances at the low-middle layer, combining with the intense development of mesoscale rain-mass and cloud - mass. The strong quasi stationary meso-scale rain-belt was the prominent characteristic of the rainstorm process. （3） The severe precipitation process was mainly caused by the multi-scale merging processes of convective clouds. Heavy rainfall occurred at the evolution period of merged clouds. （4） High humidity, positive vorticity and upward current, which led to the energy release of baroclinic instability and the increase of vertical vorticity, help to form heavy precipitation. When the heavy rain began the specific humidity was increased rapidly and the cloud liquid water reduced abruptly.