The Spatiotemporal Variations of Runoff in the Yangtze River Basin under Climate Change

Abstract

A better understanding of the runoff variations contributes to a better utilization of water resources and water conservancy planning. In this paper, we analyzed the runoff changes in the Yangtze River Basin (YRB) including the spatiotemporal characteristics of intra-annual variation, the trend, the mutation point, and the period of annual runoff using various statistical methods. We also investigated how changes in the precipitation and temperature could impact on runoff. We found that the intra-annual runoff shows a decreasing trend from 1954 to 2008 and from upper stream to lower stream. On the annual runoff sequence, the upstream runoff has a high consistency and shows an increasing diversity from upper stream to lower stream. The mutation points of the annual runoff in the YRB are years 1961 and 2004. Annual runoff presents multitime scales for dry and abundance changes. Hurst values show that the runoffs at the main control stations all have Hurst phenomenon (the persistence of annual runoff). The sensitivity analyses of runoff variation to precipitation and temperature were also conducted. Our results show that the response of runoff to precipitation is more sensitive than that to temperature. The response of runoff to temperature is only one-third of the response to precipitation. A decrease in temperature may offset the impact of decreasing rainfall on runoff, while an increase in both rainfall and temperature leads to strongest runoff variations in the YRB.

Projected Effects of Climate Change on Future Hydrological Regimes in the Upper Yangtze River Basin, China

“…Several previous studies have estimated the hydrological change response to climate change over the YRB. Xiao et al [10] analyzed the intra-annual variations, tendencies, and mutational sites of runoff during the historical period in the YRB. Gu et al [11] found that the runoff in the northern part of the Yangtze River will increase by approximately 10% from 2070 to 2099 due to climate change according to RegCM4.0 of the SRES A1B scenario.…”

The Multi-Scale Temporal Variability of Extreme Precipitation in the Source Region of the Yellow River

“…These statistical methods include the Cumulative Anomaly Curve Method [25], Mann-Kendall (MK) Nonparametric test [26], Linear/Nonlinear regression analysis, T test, and etc. [27,28]. Besides these technologies, wavelet analysis has received increasing attention and has been widely applied to many fields of hydrology to elucidate localized characteristic of non-stationary time series both in temporal and frequency domains.…”

Characteristics of Climate Change in the Lancang-Mekong Sub-Region

“…It can be used to describe the average variation of interdecadal variability quantitatively. For sequence x, the cumulative anomaly of t at a certain time is expressed as [29]:…”

“…Meng et al [28] used linear regression, five-year moving average, the Mann-Kendall test, cumulative variance analysis, and Pettitt to test changes in temperature and precipitation in the Hexi Corridor, Northwest China's Gansu province. Using various statistical methods, temporal and spatial characteristics, trends, and abrupt points, the annual variation periods of temperature and precipitation in the Yangtze River basin of China have been analyzed [29]. In addition, based on available data, researchers can analyze future trends of temperature and precipitation.…”