Variation Analysis of Streamflows from 1956 to 2016 Along the Yellow River, China

Abstract

With the change of climate and the impacts of human activities, the water resources crisis of the Yellow River is becoming increasingly serious. How and why did the streamflows of the Yellow River basin change? Based on observed annual runoff data (1956–2016) of 10 main hydrological stations along the Yellow River, the linear regression method, the Spearman rank correlation method and the Mann-Kendall test method are used to analyze runoff trend. The orderly clustering method, the sliding t test method and the Lee-Heghinian Method are used to identify the abrupt change point. Finally, the wavelet analysis method is used to identify runoff time series period. The results show that: (1) With the exception of the streamflow of Tangnaihai, the streamflows of all examined stations have significantly declining trends. The decrease of the streamflow from the upper to the middle to the lower reaches is becoming more and more obvious; (2) The runoff of the Yellow River has changed greatly. The abrupt change point at Tangnaihai occurred in 1989. The abrupt change points of the other stations took place in 1985; (3) The runoff along the Yellow River presents multi-time scale changes. The streamflows appear to have strongest periods of 25–40 years with a 40-year scale, which indicate the alternate oscillations of the high and the low water periods. The periods of <6 and 7–24 years are not stable and are complicated. The first main period of runoff in the Yellow River is 30 years; (4) The streamflow upstream of Tangnaihai station is mainly affected by the climate. The streamflows downstream of Tangnaihai station are influenced by human activities, especially water extraction and diversion and the operations of the large reservoirs. These research results have important practical guiding significance for hydrological forecasting, evaluation and management of water resources, construction of water conservancy projects and sustainable utilization of water resources in the region.

Hydrologic Response in an Urban Watershed as Affected by Climate and Land-Use Change

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“…Both climate variation and human actions act as stressors that contribute to putting water resources under severe pressure [2]. Intensive human activities apart from climate change, such as land-use change, urbanization, economic development and population growth, have posed unprecedented impacts on watershed hydrological conditions.…”

Impacts of Climate Change and Land Use/Cover Change on Regional Hydrological Processes: Case of the Guangdong-Hong Kong-Macao Greater Bay Area

“…However, the Mann-Kendall method only has good performance in detecting the trend and change point of the mean value time series; to enhance the reliability of the results, this study adopts the sliding t-test method as an auxiliary method, which can detect the change point by testing whether the difference between the mean values of two samples is significant. Specifically, in the case that the Mann-Kendall test results are not significant, it is necessary to use the sliding t-test method to test the change point (Coron et al, 2012;Chen et al, 2018;Wang X et al, 2018).…”

“…The sliding t-test method has been commonly used to detect the change points in the time series of hydrometeorological variables such as precipitation, SF, and temperature by examining whether the difference between the means of the two sample groups is significant (Wang X et al, 2018;Hu et al, 2020). If the difference exceeds a certain level of significance, it can be assumed that there is a qualitative change.…”

Estimating the Responses of Hydrological and Sedimental Processes to Future Climate Change in Watersheds with Different Landscapes in the Yellow River Basin, China

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