Comparison of Different Approaches to Seprating Human and Climatic Impacts on Run-off Changes in Basins

Document Type : Research Article

Authors

1 M.s Student of Water Resources Engineering, Tarbiat Modares University

2 Assistant Professor of Water Resources Engineering, Tarbiat Modares University

Abstract

Climate variations and human activities are among the most important factors affecting water resources and they have played a major role in river flow changes over the past decades. Therefore, determining the contribution of each of these two factors to river flow changes can help to manage regional water resources in policy and development of consistent strategies. To determine the contribution of each of the human and climatic factors in river flow changes, there are different approaches, each of which have their own assumptions and uncertainties in determining the contribution of each of the factors. Accordingly, in this study, using three conventional approaches used to distinguish between human and climatic effects including data-driven modeling, statistical and analytical approaches, the contribution of human and climatic impacts to changes in run-off in the Karkheh dam basin and its four main sub-basins during the period 1980-2014 is estimated and the range of changes in results and the sensitivity and reliability of their outcomes have been analyzed. The results show that all three approaches are sensitive to the duration of the statistical period and the extreme events and demonstrate a high range of uncertainty in their results in terms of the contribution of human activities and climate fluctuations to reducing river flow. Thus, the contribution of human activities in reducing river flow, based on these three approaches across the basin, is between 60 to 83 percent, and the contribution of climate variations is between 17 to 40 percent.

Keywords

Main Subjects


[1].Seyoum, W.M., Milewski, A. M., and Durham, M.C., Understanding the relative impacts of natural processes and human activities on the hydrology of the Central Rift Valley lakes, East Africa. Hydrological processes, 2015; 29(19), 4312-4324.
[2]. Wang, X., He, K., and Dong, Z., Effects of climate change and human activities on runoff in the Beichuan River Basin in the northeastern Tibetan Plateau, China. Catena, 2019; 176, 81-93.‏
[3].Du, J., He, F., Zhang, Z., and Shi, P., Precipitation change and human impacts on hydrologic variables in Zhengshui River Basin, China. Stochastic environmental research and risk assessment, 2011; 25(7), 1013-1025.
[4].Dey, P., and Mishra, A., Separating the impacts of climate change and human activities on streamflow: A review of methodologies and critical assumptions. Journal of Hydrology, 2017; 548, 278-290.
[5].Wang, S., Yan, M., Yan, Y., Shi, C., and He, L., Contributions of climate change and human activities to the changes in runoff increment in different sections of the Yellow River. Quaternary International, 2012; 282, 66-77.
[6].Kong, D., Miao, C., Wu, J., and Duan, Q., Impact assessment of climate change and human activities on net runoff in the Yellow River Basin from 1951 to 2012. Ecological engineering, 2016; 91, 566-573.
[7].Huang, S., Liu, D., Huang, Q., and Chen, Y., Contributions of climate variability and human activities to the variation of runoff in the Wei River Basin, China. Hydrological Sciences Journal, 2016; 61(6), 1026-1039‏.
[8].Liu, D., Chen, X., Lian, Y., and Lou, Z., Impacts of climate change and human activities on surface runoff in the Dongjiang River basin of China. Hydrological Processes: An International Journal, 2010; 24(11), 1487-1495.
[9].Tang, J., Yin, X. A., Yang, P., and Yang, Z., Assessment of contributions of climatic variation and human activities to streamflow changes in the Lancang River, China. Water resources management, 2014; 28(10), 2953-2966.
[10].Yan, X., Bao, Z., Zhang, J., Wang, G., He, R., and Liu, C., Quantifying contributions of climate change and local human activities to runoff decline in the upper reaches of the Luanhe River basin. Journal of Hydro-environment Research, 2018.‏
[11].Chang, J., Zhang, H., Wang, Y., and Zhu, Y., Assessing the impact of climate variability and human activities on streamflow variation. Hydrology and Earth System Sciences, 2016; 20(4), 1547-1560.
[12].Tsai, Y., The multivariate climatic and anthropogenic elasticity of streamflow in the Eastern United States. Journal of Hydrology: Regional Studies, 2017; 9, 199-215.
[13]. Li, C., Wang, L., Wanrui, W., Qi, J., Linshan, Y., Zhang, Y, et al. An analytical approach to separate climate and human contributions to basin streamflow variability. Journal of hydrology, 2018; 559, 30-42.‏
[14]. Xin, Z., Li, Y., Zhang, L., Ding, W., Ye, L., Wu, J, et al. Quantifying the relative contribution of climate and human impacts on seasonal streamflow. Journal of Hydrology, 2019; 574, 936-945.‏
[15].Delavar, M., Hajihosseiny, H., and Morid, S., Water and Agriculture Resource Modeling Report in Upper basin of Karkhe Dam. Khuzestan water and power authority, 2018.[Persian]
[16].He, Y., Qiua, H., Song, J., Zhao, Y., Zhang, L., Hu, S, et al. Quantitative contribution of climate change and human activities to runoff changes in the Bahe River watershed of the Qinling Mountains, China. Journal of Hydrology, 2019; In Press, Accepted Manuscript.
[17].Pettitt, A. N., A non‐parametric approach to the change‐point problem. Journal of the Royal Statistical Society: Series C (Applied Statistics), 1979; 28(2), 126-135‏.
[18].Pohlert, T., Non-parametric trend tests and change-point detection, 2016; CC BY-ND, 4.
[19]. Fu, B. P., On the calculation of the evaporation from land surface. Sci. Atmos. Sin, 1981; 5(1), 23-31.‏
[20]. Schaake, J. C., and Liu, C., Development and application of simple water balance models to understand the relationship between climate and water resources. In New Directions for Surface Water Modeling Proceedings of the Baltimore Symposium, 1989, May.
[21].Wang, S., Wang, Y., Ran, L., and Su, T., Climatic and anthropogenic impacts on runoff changes in the songhua river basin over the last 56 years (1955–2010), Northeastern China. Catena, 2015; 127, 258-269.
[22].Zhang, L., Dawes, WR., and Walker, G.R., Response of mean annual evapotranspiration to vegetation changes at catchment scale. Water resources research, 2001; 37(3), 701-708.