Hydrological Components Variability under the Impact of Climate Change in a Semi-Arid River Basin

Xuan Zhang,Fanghua Hao,Xiao Wang,Yang Xu,Chong Li

doi:10.3390/w11061122

Xuan Zhang, Fanghua Hao + Show 3 more

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https://doi.org/10.3390/w11061122

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Abstract

With increased attention paid to the changes of global climate, the impacts on hydrological processes remain poorly understood in specific basins. In this study, we selected Luanhe River Basin, which is an important source of water supply to Beijing and Hebei, as a case study for the analysis of the combined impact of precipitation and temperature change to hydrological components in a semi-arid river basin. This study investigated the change of the blue water flow (BWF), green water flow (GWF), and green water storage (GWS) by employing the SWAT (Soil and Water Assessment Tool) model and stochastic methods in different time scales during 1960 to 2017. The contribution of climate changes to hydrological change were quantified by 16 hypothetical scenarios by recombining climatic data. The results show that the annual daily maximum and minimum temperature (Tmax, Tmin) increased while their differences (DTR) decreased. However, there was no significant trend in annual precipitation and hydrological components. The trend of precipitation has a positive impact to the change of all three hydrological components. Although precipitation contributes more to changes in hydrological components, more attention also needs to be given to the change of DTR, which has positive impact of GWF that contrasts with that of BWF and GWS. Seasonal scale studies of these changes suggested that more attention should be paid to the climate change in spring and winter when the hydrological components were more sensitive to climate change. Our results summarized hydrological components variability under the impact of climate change and demonstrated the importance of analyses at different time scales, which was expected to provide a reference for water resources management in other semi-arid river basins.

Highlights

Climate change has been recognized as one of the major threats to the earth environment in the 21st century [1,2]
The increase of precipitation would lead to the increase of all three hydrological components, while the increase of diurnal temperature range (DTR) would reduce the increasing of green water flow (GWF) and decreasing of blue water flow (BWF)
With significant increasing of the temperature in all four seasons, we noticed that temperature, especially the lowest temperature (Tmin ) in winter, increased faster than that of other seasons, which resulted in a significant decrease in winter DTR

Summary

Introduction

Climate change has been recognized as one of the major threats to the earth environment in the 21st century [1,2]. Changes in temperature and precipitation patterns are expected to alter regional climates and hydrological systems [3], affecting freshwater availability at the regional scale [4]. The conflict of freshwater consumption between the human society and ecosystem may threat socio-economic sustainability and ecosystem health (e.g., leading to ecosystem degradation). Improved understanding of water availability for both humans and ecosystems in the context of climate change is critical for better water resources management. As far as the hydrological cycle is concerned, the composition of water resources includes blue water (BW) and green water (GW). Blue water is critical for domestic and industrial water consumption, while green water is crucial for supporting plant growth in rain-feed regions [5].

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