Fractal analysis of daily rainfall in Karkheh and Dez catchment

Precipitation is important climatic varibles which is directly involved the hydrological cycle. Iran is considered the most arid and semi – arid regions of the world due to lack rainfall and their inappropriate distribution, which has always faced water shortage important limitations of natural resources.Therefore, the present study was conducted with the aim of extracting scale behavior and identifying (long – term and short – term) precipitation memory of two Karkheh and Dez catchment. For this purpose, Precipitation data of two Karkheh and Dez catchment were used over a period of 60 years (1959 – 2019). The results showed that the stations both areas have 2 rainfall regimes. In the study precipitation regimes all stations, two basins were identified. The small – scale precipitation regime has a long – term memory and a stable time series. However the large – scale precipitation regimes has a short – term memory and its time series is static except Doab and Darreh Takht station. both precipitation regimes show completely different scale behavior. the relationship between precipitation scale behavior and topography of the study area was calculated using pearson correlation test. The results show that there is no significant relationship between Karkheh basin both precipitation regimes. but in Dez basin, there is a significant correlation the small – scale precipitation regime, but there is no significant correlation the large – scale precipitation regime. This can be due to the conflicting and heterogeneous topographic situation in different parts of the region in Karkheh