Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin

The present study aims to investigate the homogeneity of runoff time series and also to review the existence of trends in Tale Zang hydrometric station (the hydrometric station at the inflow into the Dez reservoir) runoff, using 61 years (1956–2016) daily recorded data. The Pettit test, which is a c...

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Main Authors: Hooman Gholami, Yahya Moradi, Morteza Lotfirad, Mohammad Amin Gandomi, Nooredin Bazgir, Manoochehr Shokrian Hajibehzad
Format: Article
Language:English
Published: IWA Publishing 2022-02-01
Series:Water Supply
Subjects:
Online Access:http://ws.iwaponline.com/content/22/2/1216
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author Hooman Gholami
Yahya Moradi
Morteza Lotfirad
Mohammad Amin Gandomi
Nooredin Bazgir
Manoochehr Shokrian Hajibehzad
author_facet Hooman Gholami
Yahya Moradi
Morteza Lotfirad
Mohammad Amin Gandomi
Nooredin Bazgir
Manoochehr Shokrian Hajibehzad
author_sort Hooman Gholami
collection DOAJ
description The present study aims to investigate the homogeneity of runoff time series and also to review the existence of trends in Tale Zang hydrometric station (the hydrometric station at the inflow into the Dez reservoir) runoff, using 61 years (1956–2016) daily recorded data. The Pettit test, which is a common method in investigating the homogeneity of time series, was used to identify change points. Both Mann-Kendall and auto-correlated Mann-Kendall tests were applied to analyze the existence or non-existence of trends in each annual, seasonal, and monthly time series observed in a runoff. In time series, significant trends at the 95% level of confidence were recognized, upper and lower limit values were presented for Sen's slope and it was tested for the increasing or decreasing trends in nature. Based on the results of this study, the significant change point at the 95% level of confidence was recognized in the annual, spring, summer, autumn, March, May, June, July, August, September, and October data sets in 1997,1997, 1999, 1997, 1999, 1999, 1999, 1997, 2000, 2007 and 2008, respectively. Analyzing the existence of a trend at the 95% level of confidence indicated that in spring, and in March, September, and October, for both Mann-Kendall and auto-correlated Mann-Kendall tests, the trend is significant and additive until the change point. HIGHLIGHTS Investigating the changes in long term runoff time series at the Tale Zang hydrometric station for the first time.; Investigating the magnitude of the change point or trend at the 95% level of confidence.; Studying the existence or nonexistence of trends before and after the change point of confidence.; Determining the upper and lower limits of Sen's slope.; Assisting water resource planners to make appropriate decisions.;
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spelling doaj.art-74852c8613ff43d1bfd8d0bc98efd7522022-12-21T23:51:35ZengIWA PublishingWater Supply1606-97491607-07982022-02-012221216123010.2166/ws.2021.357357Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basinHooman Gholami0Yahya Moradi1Morteza Lotfirad2Mohammad Amin Gandomi3Nooredin Bazgir4Manoochehr Shokrian Hajibehzad5 Khuzestan Water and Power Authority (KWPA), Ahvaz, Iran Khuzestan Water and Power Authority (KWPA), Ahvaz, Iran Civil Engineering and Architecture Faculty, Shahid Chamran University of Ahvaz, Ahvaz, Iran Khuzestan Water and Power Authority (KWPA), Ahvaz, Iran Khuzestan Water and Power Authority (KWPA), Ahvaz, Iran Khuzestan Water and Power Authority (KWPA), Ahvaz, Iran The present study aims to investigate the homogeneity of runoff time series and also to review the existence of trends in Tale Zang hydrometric station (the hydrometric station at the inflow into the Dez reservoir) runoff, using 61 years (1956–2016) daily recorded data. The Pettit test, which is a common method in investigating the homogeneity of time series, was used to identify change points. Both Mann-Kendall and auto-correlated Mann-Kendall tests were applied to analyze the existence or non-existence of trends in each annual, seasonal, and monthly time series observed in a runoff. In time series, significant trends at the 95% level of confidence were recognized, upper and lower limit values were presented for Sen's slope and it was tested for the increasing or decreasing trends in nature. Based on the results of this study, the significant change point at the 95% level of confidence was recognized in the annual, spring, summer, autumn, March, May, June, July, August, September, and October data sets in 1997,1997, 1999, 1997, 1999, 1999, 1999, 1997, 2000, 2007 and 2008, respectively. Analyzing the existence of a trend at the 95% level of confidence indicated that in spring, and in March, September, and October, for both Mann-Kendall and auto-correlated Mann-Kendall tests, the trend is significant and additive until the change point. HIGHLIGHTS Investigating the changes in long term runoff time series at the Tale Zang hydrometric station for the first time.; Investigating the magnitude of the change point or trend at the 95% level of confidence.; Studying the existence or nonexistence of trends before and after the change point of confidence.; Determining the upper and lower limits of Sen's slope.; Assisting water resource planners to make appropriate decisions.;http://ws.iwaponline.com/content/22/2/1216non-parametric testpettit testrunoffsen's slope
spellingShingle Hooman Gholami
Yahya Moradi
Morteza Lotfirad
Mohammad Amin Gandomi
Nooredin Bazgir
Manoochehr Shokrian Hajibehzad
Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
Water Supply
non-parametric test
pettit test
runoff
sen's slope
title Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
title_full Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
title_fullStr Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
title_full_unstemmed Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
title_short Detection of abrupt shift and non-parametric analyses of trends in runoff time series in the Dez river basin
title_sort detection of abrupt shift and non parametric analyses of trends in runoff time series in the dez river basin
topic non-parametric test
pettit test
runoff
sen's slope
url http://ws.iwaponline.com/content/22/2/1216
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AT mohammadamingandomi detectionofabruptshiftandnonparametricanalysesoftrendsinrunofftimeseriesinthedezriverbasin
AT nooredinbazgir detectionofabruptshiftandnonparametricanalysesoftrendsinrunofftimeseriesinthedezriverbasin
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