Response of extreme precipitation to climatic warming in the Weihe river basin, China and its mechanism

Abstract

As global warming continues, extreme precipitation events occur frequently in inland areas, seriously affecting human security and the ecological environment. Spatiotemporal evolution of extreme precipitation as well as response of extreme precipitation to climatic warming and its mechanism were investigated by considering the Weihe river basin in a monsoon transition zone of China as a research object. The results indicate that while the annual average temperature of the Weihe river basin increased with fluctuations from 1966 to 2017, except for the consecutive dry days (CDD) and simple daily intensity index that increased slightly, the other extreme precipitation indices (consecutive wet days, R25, and Rx5day) tended to decrease. Moreover, except for the CDD, the other four indices gradually increased from the northwest to the southeast, showing a similar trend to the temperature. The relationship between the 95th percentile threshold and temperature (hereinafter referred to as the P 95d–T relationship) in the Weihe river basin demonstrates the hook structure and its strength in terms of response is mainly dominated by the super-Clausius–Clapeyron (C–C) and C–C scaling. Furthermore, the peak temperature rises gradually from the northwest to the southeast. The results can provide important reference for the prediction of climate change and future studies of disaster risk in the Weihe river basin.

Response Time of Vegetation to Drought in Weihe River Basin, China

“…The Weihe River Basin (WRB, 104 • 00 E to 110 • 20 E and 33 • 50 N to 37 • 18 N) is located in the southern part of the Yellow River. It covers an area of approximately 13.48 × 104 km 2 (Figure 1a). The northwest of the WRB is higher and which belongs to the Loess Plateau; the southeast is lower and belongs to the plain region.…”

“…According to the sixth assessment report released by the United Nations Intergovernmental Panel on Climate Change (IPCC) in 2021, the global average surface temperature in 2011-2020 has increased by 1.09 • C compared with pre-industrialization (1850-1900) [1]. The temperature rise rate in the Weihe River Basin (WRB) is 0.35 • C/10a [2]. In the context of global warming, the frequent occurrence of drought has a huge impact on the WRB the maximum correlation coefficient between NDVI and SPEI/SPI and the corresponding drought time scale in the WRB by correlation analysis, and to determine the response time of vegetation (represented by the NDVI) to drought (represented by the SPEI and SPI); and (4) to determine the RTVD over different land use types.…”