the effect of climate change on flow regime using two meteorological and hydrological indices

an important and fundamental issue in iran is to utilize water and to avoid wasting it. therefore, climate change can be considered as an effective factor on water resources. the most tangible climate change phenomenon is drought which is much important to be identified. in this study, the effect of climate changes on flow rate in bashar river, shahmokhtar station of yasouj city was evaluated using standard index of annual precipitation (siap) and standard index of flow occurrence probability using statistics of 39 years since 1971-1972 to 2009-2010. the best distribution was chosen using smada software and the amount of flow was estimated based on considered occurrences probability. the results showed that, the flow rate decreases by 35.9% as a result of precipitation reduction. while, returning the amount of flow rate to the humid state by increasing the amount of precipitation after drought, will be with lag. the reduction phenomenon is exacerbated by other factors such as degradation, overuse, etc. which necessitate the need for water resources management and it is feasible by improving water use in agriculture, industry, etc.