Investigating the Characteristics of Rain in Relation to Erosion in the West of Iran.

Raindrop size distribution and kinetic energy are main parameters for splash erosion which related to rainfall intensity. To study rain characteristics like raindrop size distribution, kinetic energy, splash erosion effect of natural raindrops using two methods-stain and flour pelletwas assessed in seven sinoptic meteorology stations in Kurdistan province west of Iran.Calibration equations of the above methods were determined by droping raindrops from a certain height at terminal velocity and using them in turn, the diameter of the raindrops was calculated. then the correlation between the diameter of the drops and the rainfall intensity was investigated.the mean and median of raindrops diameter were maximum in Marivan, station and minimum in Zarineh. statistical analysis of the data using GLM distribution which is appropriate for unequal data was used. It was determined that the different between the two methods was significant and also the duncan test was used to compare the means. It showed that the stain method is more appropriate than flour pellet method. through calculating the kinetic energy of the raindrops and investigating the correlation between kinetic energy and rainfall intensity, equations were suggested for different areas of the province. then the  Language of abstract2 (720)erosivity of rain using the Wieshmaier-Smith equation was calculated for ?? storms. Marivan station has the highest amount of erosivity energy. splash erosion which was made by splash cups was established in meteorology stations and they were investigated to assess the relationships. splash rate is dependent on kinetic energy and rainfall intensity. the correlation coefficient of them is significant in three regions in the province. Other features of rain such as terminal velocity? vuluminal mean of raindrops and statistical descriptions have been investigated.