Abstract

Abstract In the context of global warming and increasing human activities, the acceleration of the water cycle will increase the risk of basin drought. In this study, to analyze the spatial and temporal evolution characteristics of hydrological and meteorological droughts over the Hanjiang River Basin (HRB), the Standardized Precipitation Index (SPI) and Standardized Runoff Index (SRI) were selected and applied for the period 1961–2018. In addition, the cross-wavelet method was used to discuss the relationship between hydrological drought and meteorological droughts. The results and analysis indicated that: (1) the meteorological drought in the HRB showed a complex cyclical change trend of flood-drought-flood from 1961 to 2018. The basin drought began to intensify from the 1990s and eased in the 2010s. The characteristics of drought evolution in various regions are different based on scale. (2) During the past 58 years, the hydrological drought in the HRB has shown a significant trend of intensification, particularly in autumn. Also, the hydrological droughts had occurred frequently since the 1990s, and there were also regional differences in the evolution characteristics of drought in various regions. (3) Reservoir operation reduces the frequency of extreme hydrological drought events. The effect of reducing the duration and intensity of hydrological drought events by releasing water from the reservoir is most obvious at Huangjiagang Station, which is the nearest to Danjiangkou Reservoir. (4) The hydrological drought and meteorological drought in the HRB have the strongest correlation on the yearly scale. After 1990, severe human activities and climate change have not only reduced the correlation between hydrological drought and meteorological drought in the middle and lower reaches of the basin, but also reduced the lag time between them. Among them, the hydrological drought in the upper reaches of the basin lags behind the meteorological drought by 1 month, and the hydrological drought in the middle and lower reaches of the basin has changed from 2 months before 1990 to 1 month lagging after 1990.

Highlights

  • Drought is a globally and common natural disaster, which has a huge impact on human activities and life

  • The results show that the correlation between hydrological drought and meteorological drought in the base period at each scale at Huangjiagang Station and Huangzhuang

  • It is of great importance to prevent the hazards of sudden drought caused by the complicated periodic changes of meteorological drought

Read more

Summary

Introduction

Drought is a globally and common natural disaster, which has a huge impact on human activities and life. (Mishra and Singh 2010)Among them, meteorological drought refers to the phenomenon of water deficit caused by the imbalance of precipitation and evaporation in a certain period of time. It is characterized by insufficient precipitation, and the absolute precipitation of a specific duration is used as a quantitative indicator to determine the degree of drought. Hydrological drought refers to water shortages in which river runoff, reservoirs or groundwater. It affects the three major links of evaporation, infiltration and runoff in the natural water cycle process, involving the surface, soil and groundwater interface, and related to the hydrological cycle and water balance, so it can better reflect the actual drought and the difficulty of drought resistance

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call