Separation of the effects of climate variability and human activities on runoff of Bakhtegan Basin

Document Type : Research Article

Authors

1 P.hD. Student, Faculty of Natural Resources, University of Tehran, Karaj

2 Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj

3 Assistant Professor, Department of Civil Engineering, Isfahan University of Technology, Isfahan

Abstract

Arid and semi-arid ecosystems are very sensitivity to changes. Fluctuations in climate variables and increasing human activities; result in the changes in hydrological processes of these ecosystems, and consequently, their structures degradation. In this study, hydro-climatic data of the Bakhtegan basin for the period of 1972–2011, were analyzed to assess effects of climate variability and human activities on hydrology processes of the study area. A combined analysis of statistical tests for trend analysis and change pointe detection indicated that the basin runoff had have a significant decreasing trend over last 40 years. The change point of runoff occurred in 1999, the annual runoff of the study basin divided into two periods. The period of 1972–1999 was used as the base period for calibration and validation, and the period of 2000-2011 as a human-induced period for the model processing. Then, the hydrologic sensitivity analysis method was the approach employed to evaluate the effects of climate variability and human activities on runoff. According to the analyses conducted, contribution of climate variability in the runoff reduction of Bakhtegan basin was estimated equal to 62.45% and contribution of human activities equal to 37.55%. These results can be very useful as a reference for regional water resources assessment; management and maintaining the integrity of regional ecosystems.
 

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1)      کاظمی، محسن، 1393، بررسی حساسیت رسوبات دریاچۀ مهارلو به فرسایش بادی و تهدیدهای احتمالی برای شهرستان‏های اطراف، دانشگاه تهران، 220.
2)       Alexandersson, H. (1986). A homogeneity test applied to precipitation data. Journal of Climatology, 6, 661–675.
3)       Alexandersson, H. and Moberg, A. 1997. Homogenization of Swedish temperature data, Part I: Homogeneity test for linear trends. Int. J. Climatol, 17(1): 25–34.
4)       Allen, RG., Pereira, LS., Raes, D., and Smith, M. (1998) Crop evapotranspiration:guidelines for computing crop water requirements. FAOIrrigation and Drainage Paper No.56. FAO, Rome, Italy.
5)       Brown, AE., Zhang, L., McMahon, TA., Western, AW., and Vertessy, RA. (2005)A review of paired catchment studies for determining changes inwater yield resulting from alterations in vegetation. Journal of Hydrology 310:28–61.
6)       Budyko, M. I. (1981). Climate and Life, Academic, San Diego, CA, 1974.Fuh, B. P.: On the calculation of the evaporation from land surface, Sci. Atmos. Sinica, 5, 23–31.
7)       Buishand, T. A. (1982). Some methods for testing the homogeneity of rainfall records. Journal of Hydrology, 58, 11–27.
8)       Dooge, JCI., Bruen, M., and Parmentier, B. (1999) A simple model for estimatingthe sensitivity of runoff to long-term changes in precipitation withouta change in vegetation. Adv Water Resour 23:153–163.
9)       Gocic, M., and Trajkovic, S. (2013) Analysis of changes in meteorological variables using Mann-Kendall and Sen's slope estimator statistical tests in Serbia. Global and Planetary Change. 100, 172-182.
10)   Helsel, DR., and Hirsch, RM. (1992) Statistical Methods in Water Resources. Elsevier. Amsterdam. ISBN 0-444-88528-5.
11)   IPCC, (2007) Climate change (2007). the physical science basis. In:Solomon S, Qin D, Manning M, Chen Z, Marquis M, AverytKB, Tignor M, Miller HL (eds) Contribution of working group Ito the fourth assessment report of the intergovernmental panel onclimate change. CambridgeUniversity Press, Cambridge.
12)   Jiang., S. H., Ren., L. L., Yong, B., Singh., V. P, Yang. X. L., and Yuan., F. (2011). Quantifying the eects ofclimate variability and human activities on runo from the Laohahe Basin in Northern Chinausing three dierent methods, Hydrol. Process, 25, 2492–2505.
13)   Kendall, MG. (1975). Rank correlation measures. Charles Griffin,London.
14)   Kong, D., Miao, C., Wu, J., & Duan, Q. (2016). Impact assessment of climate change and human activities on net runoff in the Yellow River Basin from 1951 to 2012. Ecological Engineering, 91, 566-573.
15)   Lettenmaier, DP., Wood, EF., and Wallis., JR. (1994). Hydro-climatological Trends in the Continental United States, 1948-88. J. Climat. 7, 586-607.
16)   Ma, ZM., Kang, SZ., Zhang, L., Tong, L., and Su., XL. (2008). Analysis of impactsof climate change and human activity on streamflow for a river basin.
17)   Mann., HB. (1945). Non-parametric tests against trend. Econometrica13:245–259.
18)   Milly, PCD., Dunne, KA. (2002). Macro-scale water fluxes 2. Water andenergy supply control of their inter-annual variability. WaterResour Res 38:1206.
19)   Niemann, JD., Eltahir, EAB. (2005). Sensitivity of regional hydrology toclimate changes, with application to the Illinois River basin. WaterResources Research 41: W07014.
20)   Novotny, EV., Stefan, HG. (2007). Stream ow in Minnesota: indicator ofclimate change. Journal of Hydrology 334: 319–333.
21)   Peng, D., Qiu, L., Fang, J., & Zhang, Z. (2016). Quantification of Climate Changes and Human Activities That Impact Runoff in the Taihu Lake Basin, China. Mathematical Problems in Engineering, 2016.
22)   Pettitt, A.(1979). A nonparametric approach to the change-point problem, Appl. Statist., 28, 126–135,
23)   Ren, LL., Wang, MR., Li, CH., and Zhang, W. (2002). Impacts of human activityon river runoff in the northern area of China. Journal of Hydrology 261:204–217.
24)   Salas, JD., Delleur, JW., Yevjevich, V., and Lane, WL. (1980). Applied Modelling of Hydrologic Time SerieWater Resources Publications, Littleton, CO, USA.
25)   Scanlon, BR., Jolly, I., Sophocleous, M., and Zhang, L. (2007). Global impactsof conversion from natural to agricultural ecosystem on waterresources: quantity versus quality. Water Resour Res 43:W03437.
26)   Sen, PK. (1966). Esti mates of the regression coefficients based on Kendall’s tau. Journal of the American Statistical Association. 63, 1379-1389.
27)   Shen, H., Ren, L., Yuan, F., & Yang, X. (2015). Comparative assessment of extreme climate variability and human activities on regional hydrologic droughts in the Weihe River basin, North China. Proc. IAHS, 369, 141-146.
28)   Tabari, H., and Marofi, S. (2011) Changes of pan evaporation in the west of Iran. Water Resources Management 25, 97-111.
29)   Theil, H., (1950). A rank invariant method of linear and Polynomial regression analysis, Part3, Netherlands Akademic van wetten schappen. Proceedings. 53, 1379-1412.
30)   Vogel, R, M,. and Fennessey, N. M. 1994.Flow-duration curves, I: New interpretation and confidences15intervals, J. Water Resour. Plan. Manage, 120, 485–504.
31)   Von Neumann, J. (1941). Distribution of the ratio of the mean square successive difference to the variance. Annals of Mathematical Statistics, 13, 367–395.
32)   Yuan, Y., Zhang, C., Zeng, G., Liang, J., Guo, S., Huang, L.,... & Hua, S. (2016). Quantitative assessment of the contribution of climate variability and human activity to streamflow alteration in Dongting Lake, China. Hydrological Processes.
33)   Yue, S., and Wang, CY. (2004). The Mann–Kendall test modified by effective sample size to detect trend in serially correlated hydrological series. Water Resour Manage. 18, 201–218.
34)   Yue, S., and Wang, CY. (2002). Applicability of prewhitening to eliminate theinfluence of serial correlation on the Mann-Kendall test. WaterResour Res 38:1068.
35)   Zarghami, M., Abdi, A., Babaeian, I., Hassanzadeh, Y., and Kanani, R. (2011). Impacts of climate change on runoffs in East Azerbaijan, Iran. Global and Planetary Change, 78(3), 137-146.
36)   Zhan, C. S., Jiang, S. S., Sun, F. B., Jia, Y. W., Yue, W. F., and Niu, C. W. (2014). Quantitative contribution of climate change and human activities to runoff changes in the Wei River basin, China. Hydrology and Earth System Sciences Discussions, 11(2), 2149-2175.
37)   Zhang, L., Hickel, K., Dawes, WR., Chiew, FHS., Western, AW., Briggs, PR.(2004). A rational function approach for estimating mean annualevapotranspiration. Water Resources Research. 40: W02502.
38)   Zhang, Q., Xu, CY., and Yang, T. (2009) Variability of water resource in theYellow River Basin of past 50 years, China. Water Resour Manag23:1157–1170.
39)   Zhang, X. P., Zhang, L., Zhao, J., Rustomji, P., and Hairsine, P. (2008). Response of streamflow to changes in climate and land use/cover in the Loess Plateau, China, Water Resour. Res., 44, W00A07.