Document Type : Research Paper
Authors
1 PhD Student, Department of Water science and engineering, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran
2 Department of water science and engineering, Faculty of Agriculture, Imam Khomeini International University, Qazvin, Iran
3 Associate Professor, Department of Civil and Architectural Engineering, Faculty of Engineering, Sultan Qaboos University, Muscat, Oman
Abstract
Climate change and human activities are the two main factors in the change of runoff. The purpose of this research is to determine the contribution of each of the factors of climate change and human activities on the changes in the runoff of Qazvin plain. The evaluation of the trend in the annual amounts of precipitation, runoff, air temperature, and evaporation and transpiration potential from 1369 to 1397 was determined by the Mann-Kendall test, the results showed that the runoff showed a decreasing trend at a significant level of 0.01; While the average annual air temperature was at a significant level of 0.1 and evaporation and transpiration potential was increasing at a significant level of 0.1. Despite the decrease in average annual precipitation at the basin level, there was no significant statistical trend of precipitation.Next, in order to determine the point of change in the amount of runoff, Pettit's test was used, the results showed that the change point in the annual runoff series is in 1375 based on Pettit's test and the double cumulative curve method of precipitation-runoff, then using the sensitivity analysis method Hydrologically, based on the Boudico-Zhang hypothesis, the evaluated effects of human activities and climate change on runoff changes were investigated. The results showed that the percentage of influence of climate change and human activities is (-21 mm equivalent to -161.2 percent and 0.08 mm equivalent to 61.2 percent) respectively.
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