An investigation was conducted on the hydrological underlying surface for rain-induced floods from Sanmenxia to Xiaolangdi in the mid-lower reaches of the Yellow River by means of the multiple time-phase,high-resolution remote sensing data of Landsat TM/ETM~+.

This paper carries out a numerical experiment on a flash-flood-producing rainstorm process from 3 to 5 September 2004 in Sichuan province,using NCEP/NCAR data and regional observational data as the background field.

Based on the NCEP/NCAR daily reanalysis data,the circulation background of the flash-flood-producing rainstorm over South China in June 2005 and its possible cause are analyzed.

Starting from the atmospheric circulation background and physical field diagnosis,and connecting with some meteorological observation data such as FY-2C nephogram and its products,this paper analyzes the geneses and characteristics of 7·29 torrential rain weather in Jincheng City,which provides the foundations for future forecast of torrential rain.

The results show that the flood rainstorm is closely related with lower level energy accumulation,a low-vortex shear line and the low-level jet on 700 hPa.

A contrast analysis on the course of two flood rainstorms along upper Weihe river is made.

Base on surface observation data, high altitude detection data, mesoscale automatic weather stations data, NCEP reanalysis data, and water level data, the author used the synoptic analysis and numerical model MM5 to analyze and simulate the process of the flood-causing rainstorm, and also made the comparison of the similar cases since 2000.

Statistic is made regarding flood-resulting rainstorm process and it ssynoptic systems in Liujiang valley from 1951 to 2005.

We made physical diagnosis about a flood-resulting rainstorm process in Liujiang area on 19-20 July 2004 and found that “2 ridge 1 trough” circulation background,strong low-level jet and low-level shear are the characteristic of meso-scale and lagre-scale circulation during this process.