Author(s): Haoyu Wang; Yun Deng; Min Chen; Youcai Tuo; Yanjing Yang; Yunxiao Jia

Linked Author(s): Yun DENG, Min Chen

Keywords: Climate change; Arid-hot valley; Air temperature; Water temperature; Jinsha river lower reaches

Abstract: The high temperature and high shortwave radiation in the arid-hot valley area of the Jinsha River make river water temperature in this area increase significantly under the influence of water-air interface heat exchange, and form a rare heat transport mode from high heat to low heat areas during the flow from upstream to downstream. Under the influence of climate warming and hydropower development, river morphology and thermal regimes have changed significantly, which may adversely affect the fragile ecological environment and drinking water safety in the region. However, few studies have focused on the impact of these changes on the river thermal regime in the arid-hot valley area. This study systematically investigated the spatial and temporal variation characteristics and changes of meteorological and water temperature in the basin under the influence of climate warming and hydropower construction, based on nearly 40 years of measured data (1981-2020) in the arid-hot valley area of Jinsha River basin in China and mathematical statistical methods. The research results showed that the study area was sensitive to global climate change, and the annual average air temperature of each meteorological station showed a significant warming trend (|Z|>1.96). There was a mutation between 1990 and 2010. After the sudden change, the temperature warming rate increased from an average of 0.21 ℃/10a to 0.48 ℃/10a. The fluctuation of water temperature was generally controlled by air temperature, and the periodicity was basically coordinated. Under the influence of climate warming, the water temperature increased by 0.17℃ on average during 28 years (from 1979 to 2006). The upstream hydropower construction caused a sudden change in the water temperature. The temperature rise rate increased, and the average warming trend increased by 1.01℃/10a. Meanwhile, there was a phase difference between water temperature and air temperature, and the wave amplitude decreased by 27.9%, which weakened the response degree of water temperature to air temperature. This study aims to provide more sufficient key basic data and scientific basis for climate change and its impact research.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0886-cd

Year: 2023