Application of principal component analysis in determination of effective factors on runoff generating

The initial step of each phenomenon is complementary recognizing and understanding of its relationship with other effecting and affecting phenomena. Runoff yield and flood occurrence are affected by complex factors. Therefore, defining these factors recognizing their effect on the runoff generating in the catchment can help the better planning for decreasing losses of runoff and increasing the flood in the catchment. There are several factors that affecting runoff and flood generating such as non- fundamental the exploitation of nature by man, physical and hydrological properties of the catchment. Determining the effective factors may be useful to achieve optimal models and methods for champion and reducing runoff and flood. The aim of this study was to evaluate the influence of these factors on production runoff in Hesarak catchment. In view if this, runoff of the catchment were measured using SCS method and HEC- HMS model based on five groups variables including physiographic characteristics (seven parameters), geology (three parameters), sediment types (three parameters) , land use (seven parameters) and the maximum daily rainfall and twenty one parameters. So The required layers and informations includes layers of land use, geology, Maximum daily rainfall and runoff were calculated for each subbasin. Then The informations collected after transformed and standardized, The most effective factors were determined using principal component analysis. The results showed that geology and land use are the most effective factors on runoff yield in the study area.And due the large number of variables that 2 factors justified 100% of the data variance.