Simulation of snowmelt runoff under climate change scenarios in Armand basin

Climate change is a major environmental problem because melting processes of the glaciers and snow packs are sensitive to climate change. The aim of this study, is predicting future changes in climatic parameters, estimating changes in snow covered area and snowmelt runoff under scenarios of climate change in Armand basin. To investigate the effect of climate on precipitation and temperature in Armand basin, Three models (NorESM1-M, IPSL-CM5A-LR and CSIRO-MK3.6.0) was used under the scenarios RCP8.5, RCP4.5, RCP2.6 were run, Temperature and precipitation in the next four periods (2021-2030, 2031- 2040, 2041-2050 and 2051-2060) under all three scenarios were calculated. As well as the daily images MODIS (Mod10A1) was used to determine the snow covered area in the basin. The relationship between the snow covered area with the observed temperature and precipitation was studied and has been used to predict future snow cover. The results showed that all three scenarios RCP predict rising temperature and reduced precipitation and snow cover. Studying of snowmelt runoff in the observation period (November 2000-May 2006) showed that about 47.7 of the annual runoff in the basin is related to snowmelt. Most snowmelt runoff during the winter has been created. The contribution of total water produced by melting snow during the fall and spring 34.9 and 52.8 percent respectively that Along with snowmelt, it is expected runoff will be reduced by about 0.12 cubic meters per second per year.