Hydrological Drought Regimes of the Huai River Basin, China: Probabilistic Behavior, Causes and Implications

Sun Sun,Wen Wen,Zhang Zhang,Yao Yao

doi:10.3390/w11112390

Abstract

: Hydrological droughts were characterized using the run-length theory and the AIC (Akaike information criterion) techniques were accepted to evaluate the modeling performance of nine probability functions. In addition, the copula functions were used to describe joint probability behaviors of drought duration and drought severity for the major tributaries of the Huai River Basin (HRB) which is located in the transitional zone between humid and semi-humid climates. The results indicated that: (1) the frequency of hydrological droughts in the upper HRB is higher than that in the central HRB, while the duration of the hydrological drought is in reverse spatial pattern. The drought frequency across the Shiguan River along the south bank of the HRB is higher than the other two tributaries; (2) generalized Pareto distribution is the appropriate distribution function with the best performance in modelling the drought duration over the HRB; while the Generalized Extreme Value (GEV) distribution can effectively describe the probabilistic properties of the drought severity. Joe copula and Tawn copula functions are the best choices and were used in this study. Given return periods of droughts of <30 years, the droughts in the upper HRB are the longest, and the shortest are in the central HRB; (3) the frequency of droughts along the mainstream of the HRB is higher than tributaries of the HRB. However, concurrence probability of droughts along the mainstream of the HRB is lower than the tributaries of the HRB. The drought resistance capacity of HRB has been significantly improved, effectively reducing the impact of hydrological drought on crops after 2010.

Highlights

According to the IPCC (Intergovernmental Panel on Climate Change) report, with climate change and human activities, climate extreme events such as droughts and floods are a significantly increasing trend [1,2,3]
The drought duration of normal dry years cannot lead to high drought intensity, which is caused by the significant increase in irrigation of rivers, lakes, and large reservoirs. This is the main reason for the low correlation coefficient between drought severity and drought duration in Jiangjiaji station
While the duration of the hydrological drought is in reverse spatial pattern

Summary

Introduction

According to the IPCC (Intergovernmental Panel on Climate Change) report, with climate change and human activities, climate extreme events such as droughts and floods are a significantly increasing trend [1,2,3]. Hydrological droughts, agriculture droughts, and socio-economic droughts. Severe droughts have occurred in seven major river basins of China in the past few decades [8,9,10]. Due to global warming and intensifying human activities, hydrological drought events have significantly increased all over the world, which will pose a threat to ecosystems, agriculture development, and local socio-economic development [11,12,13]. Hydrological drought events were characterized by duration, severity and drought area, and multi-dimensional hazardous phenomena [14,15]. If the individual drought characterization was analyzed, drought, in reality, cannot be revealed the serious consequence of drought in reality [16,17]

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Methods

Results

Conclusion