عنوان مقاله [English]
The climate change can be a major threat to biodiversity and ecosystem integrity. Therefore, prediction of hydrological behavior of watersheds for conservation and reconstruction of ecosystems is necessary. Latyan dam watershed as one of the mountainous basins of the country with an area of approximately 710 km2 is located northeast of Tehran and west of Damavand city. In this research, to evaluate the run-off and water balance caused by climate change, the SWAT semi-distributed hydrologic model has been used based on the data collected in the years 1988-2014. Given the high precision of the CMIP5 series models, the outputs of these models were introduced into the model under the two scenarios RCP 2.6 and RCP8.5 for the near future using the climate LARS-WG model. The result of stimulation for 2021-2050 showed that mean temperature increases by 0.75 C° for the RCP 2.6 optimistic scenario and 1.45 C° for the RCP 8.5 pessimistic scenario. In addition, rainfall was reduced by 2 % in RCP 8.5 and 5 % in RCP 2.6. The result for water flow showed that high level of water flow decreases by 2.4 cubic meters per second in May and increases by 1.49 in April. The water flow in RCP 8.5 scenario for May and June was greatly reduced, which can negatively affect the level of water in dam until the start of rainfall. Average evapotranspiration was increased by 3 mm in the optimistic scenario and 8mm in the pessimistic scenario which negatively affects the accessible water resource. Reduction of rainfall was predicted for the two scenarios. The results of the research emphasize the necessity of applying appropriate policies for adaptation of ecosystem based climate change in the management of the Latyan catchment area.