Using the data of aircraft artificial precipitation enhancement operation from 1991 to 2002 in Gansu province, the situation of it was analyzed statistically in late spring and early summer.

The formula for estimating the catalyst dosage of aircraft cloud seeding in stratiform clouds is put forward,on the basis of the supercooled cloud water content,saturation vapor density difference between ice and water surface,average accretion mass of ice crystal groups,effective diffusional scope of a .

Numerical Analysis of Statistical Power in Precipitation Enhancement of Non-randomized Experiment and Statistical Method Improvement;

An artillery precipitation enhancement operation of hail clouds at the Wuqing district in Tianjin on 2 August 2000 is analyzed in detail by use of WSR81S Radar data at Tianjin and the corresponding surface precipitation data.

Evaluation system of artificial precipitation effect based on the area rainfall station material;

A new concept of real-time storage standard of reservoir is put forward for the sake of work of artificial precipitation on condition that the reservoirs are guaranteed to store full water and rainstorm and no flood disasters.

This paper analyses climatic features of cloud and precipitation on the Leizhou Peninsula,researches cloud dynamics and forming mechanism of precipitation and artificial precipitation and catalyst,and summarizes test results.

The artificial rainfall was simply introduced.

Connecting with the theory of the artificial rainfall, this paper analyzes and sums up the experiences of Changzhi City in carrying out the the artificial rainfall by using the 37 ack-ack and rocket shell in many years, and introduces some applied techniques used in the actual ground artificial rainfall techniques.

According to the echo area and intensity change of target cloud,the qualitative judgment that the artificial rainfall is effective or not can be gotten.

Brief summaries of defects and experience of weather modification were confined to main weather modification activities that appear to be based on acceptable physical principles and which have been tested in the fields.

The GIS-based operation system of weather modification for prefecture-level institutions consists of such parts as data analysis and transmission,operation control,and effectiveness evaluation,etc.

The problems and solving scheme against the interruption of the Yellow River by increasing precipitation us-ing weather modification was investigated based on the Natural Cybernetics.