To study hydrological drought or regional analysis method, using the daily data of twelve atmospheric pollutant stations of ATRAK, the minimum flow rate was calculated with seven days' duration at each station.in order to generalize the analysis of the point on the studied area, appropriate regional model for 7-day minimum flow with the return period of ten years extracted by the regression model and the minimum flow was estimated at the regional level for twenty stations. Considering the measured data at the stations in the area, the daily hydrometric data of the stations was simulated for 50 years using the DIMGEN generator. The minimum seven-day flow was estimated with a return period of 10 years for simulated data for all stations. Then, the zoning maps of the study area were mapped to the minimum flow and the minimum flow rates were compared with two existing assumptions. The results showed that the minimum flow rates in the data generation mode have been decreased and drought have spread throughout the region. By studying the zoning maps, it was found that in case of possible warming and reduced rainfall, drought dangers have increased and the drought-prone areas are seriously affected, which should be considered in the management of water resources.