TY - JOUR ID - 67034 TI - Investigating the Trend of Temperature and Rainfall and its Effects on the Taleghan Dam Water Resources JO - Iranian Journal of Soil and Water Research JA - IJSWR LA - en SN - 2008-479X AU - Ezzati, Manijeh AU - Shokoohi Langeroodi, Alireza AU - Singh, Vijay P. AU - Noori, Mojtaba AD - Former Graduate Student, Water Engineering department, International University of Imam Khomeini, Qazvin, Iran AD - Professor, Water Engineering Department, International University of Imam Khomeini, Qazvin, Iran AD - Distinguished Professor of Biotechnology and Agricultural Engineering Department, Texas A&M University, College Station, USA AD - Manager, Alborz Regional Water Company, Karaj, Iran Y1 - 2018 PY - 2018 VL - 49 IS - 4 SP - 705 EP - 716 KW - Climatic changes KW - trend KW - Climatic turning point KW - Snow KW - Taleghan Dam DO - 10.22059/ijswr.2017.210883.667493 N2 - Impacts of observed changes in the amount and temporal pattern of precipitation on surface runoff and extreme hydrological events at local and regional scale in dry and semi-dry parts of the country is a controversial subject. In this study, the effect of observes changes in temperature and precipitation on annual and monthly discharges at the mouth of the Taleghan Dam using historical hydrometric and climatic data were investigated. The results of trend analysis indicated that while the total rainfall didn’t show any type of trend, both temperature and runoff increased during winter, especially in months of February and April. Moreover, a positive turning point was observed in the temperature at the significant level of 99% in the year of 1984. This achievement introduced the fact of changing the temporal pattern of snowfall and replacing the season of spring with winter, in terms of snow melting period, across the basin. Further investigation on snow cover, using TERRA images during 2000-2014, revealed that the area of snow cover in February had a meaningful negative trend. Regarding all factors, including positive trend in temperature, reducing the snow cover area, spring flow reduction and winter flow increase despite of constant volume of annual precipitation and runoff, confirmed the occurrence of climatic changes in the Taleghan watershed. In conclusion, the climatic changes imposed their influences on the watershed by changing the precipitation pattern from snow to rainfall and by shifting the season of snow melting. This study suggests that due to the lack of trend in the annual input flow to the reservoir dam, anthropogenic effects, in terms of changing the pattern and amount of runoff in the Taleghan watershed, are not considerable. UR - https://ijswr.ut.ac.ir/article_67034.html L1 - https://ijswr.ut.ac.ir/article_67034_ff5bd5c7f12c4908ffdf960a048be9fb.pdf ER -