The application of factor analysis in the influential variables and their relation to hydrological droughts; (Case study: LorestanWatershed province)

Drought is one of the most important phenomena in environmental and climatic changes is an integral part. Reversible phenomenon and an inevitable reality in the arid and semiarid climates lack of rainfall that occurred in a period and can affect large parts. Influential variables in determining the hydrological drought and relationship variables as the most important coping strategy are consumption losses due to drought. Analysis of the applicable principal components factor analysis and multivariate statistical methods to analyze data. Due to the large variety of variables affect the hydrological drought، this study introduces an important variable that had the main role، and determine the effectiveness of each of the research necessary to find them. For this purpose the data for 25 hydrometeric stations located in Lorestan province in terms of geographic distribution and diversity of an area within a thirty-year period (59-1358 to 89-1388) were considered. Physiographic area using data from topographic maps and then factor analyzed 15 variables measured in the selected areas was performed with SPSS software. The study also uses the main component analysis and linear structural relations by LISREL software، and how the relationships of the variables were analyzed. The final model، reflecting the positive impact of each component of the study variables، which، respectively: average rainfall، drainage area and has the highest density levels influence the incidence of hydrological drought in the region are studied.