Response of Runoff Change to Extreme Climate Evolution in a Typical Watershed of Karst Trough Valley, SW China

Abstract

Identifying the response of runoff changes to extreme climate evolution was of great scientific significance for the rational regulation of watershed water resources and the prevention of hydrological disasters. However, the time–frequency response relationships were not clear. The Yinjiang River watershed, a typical watershed with karst trough valley areas, was chosen to identify the impact of different climatic driving factors on runoff changes from 1984 to 2015. Continuous wavelet transform (CWT), cross-wavelet transform (XWT), and wavelet coherence transform (WTC) were performed to study the response relationship and time–frequency effect between runoff changes and extreme climate change at different time scales. The main results showed that: (1) Twelve extreme climate indices (ECIs) were detected to have a significant impact on runoff changes, mainly on a 6-year time scale; (2) The R10 and Rx1day in extreme precipitation index and SU34.4 and TNx in the extreme temperature index were the main driving factors of runoff changes, which had relatively large impacts on runoff changes in high and low energy vibration regions. However, the remaining eight ECIs that passed the 0.05 confidence level showed relatively large impacts on runoff changes only in low energy vibration regions; (3) The transition of the interaction between ECIs and runoff changes in high and low time–frequency scales was related to the abrupt change characteristics of the ECIs. The correlation of abrupt change was an important reason for the emergence of highly correlated regions that trigger high and low energy vibrations; (4) As a whole, the extreme precipitation events were ahead of runoff changes at the high time–frequency scale and exhibited small lag effects at the low time–frequency scale, while extreme temperature events were mainly ahead of runoff changes. This study has effectively revealed the impact of climate factors at different scales on runoff changes, and provides a theoretical understanding for regulating and managing water resources in karst basins.

Runoff Simulation of the Upstream Watershed of the Feiling Hydrological Station in the Qinhe River Based on the SWAT Model

“…Water scarcity is a prevalent issue in many locations worldwide due to rapid socioeconomic growth and a significant rise in population density [1,2]. The runoff volume of numerous basins has substantially changed due to the combined influence of climate change and human activities, resulting in a considerable impact on the water resources and channels of these basins [3][4][5]. Water science is a prominent research area among researchers worldwide.…”

Temperature Evolution of Cooling Zones on Global Land Surface since the 1900s

“…Over the past 100 years, the global average temperature has risen by 0.3-0.6 • C [1] and will be 1.8-4.0 • C higher than that of the past century by the end of the twenty-first century [2]. Global warming has accelerated the hydrological cycle and poses a potential threat to the survival and development of terrestrial ecosystems and human beings [3][4][5][6][7][8][9][10][11][12][13].…”

Projection of Future Climate Change and Its Influence on Surface Runoff of the Upper Yangtze River Basin, China

“…Temperature and precipitation are the basic meteorological factors [15]. Climate change has changed the spatial and temporal distribution patterns of global temperature and precipitation and increased the probability of extreme weather events in more than 80% of the world [16]. Climate change exhibits global and regional characteristics influenced by various factors.…”

“…Global warming is accelerating the hydrological cycle and changing the intensity and frequency of precipitation. Moreover, precipitation is directly involved in the hydrological cycle, changing the runoff of the basin [16,19,20]. The increase in temperature has changed the water resources' temporal and spatial distribution and increased the probability of extreme climate events [21,22].…”

“…Climate change has enhanced the temporal and spatial variability of precipitation and temperature, leading to the frequent occurrence of extreme weather events. Extreme weather events such as hot extreme rainstorms are more likely to cause drought and flood disasters [29], which greatly reduce the utilization capacity of regional water resources and cause significant damage to the ecological environment and human social economy [11,16,30].…”