Drought risk analysis based on multivariate copula function in Henan Province, China

Under global climate warming, the global water cycle is further accelerating, the risk of drought is increasing, and the instability and sustainability of agricultural production are seriously threatened. Northeast China, as the “granary” of China, located in the mid-high latitudes of the Northern Hemisphere, is one of the regions strongly influenced by droughts. Thus, studying the spatial and temporal distribution of drought is helpful for the development of methods for forecasting potential drought hazards in Northeast China. This study used observed data from 86 meteorological stations in Northeast China from 1961 to 2020 to calculate the standardized precipitation evapotranspiration index (SPEI) at different time scales for the past 60 years and analyzed the spatial and temporal characteristics of drought in Northeast China based on the run theory and the Mann-Kendall test. The SPEI at the annual scale showed decreasing trends with no significant mutation point. Seasonally, there was a decreasing trend of the SPEI in summer and autumn and an increasing trend in spring and winter, which indicates that drought in Northeast China has decreased in winter and spring. The annual drought frequency ranged from 25.5% to 37.6%, and the spatial characteristics of the frequency of moderate drought, severe drought, and extreme drought, respectively, showed the following distribution patterns from the western region to the central region and then to the eastern region of Northeast China: “high-low-high”, “low-high-low”, and “gradually decreasing”.

Section: Discussionmentioning

confidence: 99%

Characteristics of the Spatial and Temporal Distribution of Drought in Northeast China, 1961–2020

Wang,

Zhang,

Guo

et al. 2024

“…Figure 9c illustrates that the SCT values are all higher than the ones from before the FLWL was raised. The annual mean and maximum of the SCT are 11.40 and 16.01 billion m 3 , respectively, and the SCT values are, on average, 8.13% (1.10-12.78%) more than the ones from before the FLWL was raised. Moreover, the SCT are values, on average, 0.81 billion m 3 more than the ones from before the FLWL was raised, which is 8.53% of the…”

Section: The Risks and Benefits Of Floodwater Utilizationmentioning

confidence: 92%

“…Reservoirs are crucial for flood control and floodwater utilization and lead to conflicts between the two [2]. With growing populations and socio-economic development, water shortages in some regions are becoming more acute [3]. Therefore, enhancing floodwater utilization becomes necessary [4].…”

Section: Introductionmentioning

confidence: 99%

Research on Flood Risk Control Methods and Reservoir Flood Control Operation Oriented towards Floodwater Utilization

Zhou,

Kang,

Hou

et al. 2023

Self Cite

Since improving floodwater utilization may increase flood risk, flood risk control methods for trade-offs between these factors have research value. This study presented a flood risk control method oriented towards floodwater utilization which considers multiple main flood risk factors. The proposed method not only achieves the boundaries of the flood limited water level (FLWL) under various acceptable risks but also dynamically controls the water level to enhance floodwater utilization. A case study conducted on the Danjiangkou reservoir yielded the following results: (1) The proposed method provides FLWL dynamic control boundaries under various acceptable risks. (2) The proposed method reveals the potential to raise the FLWL, with a possibility to raise it by 1.00 m above the present FLWL under the absence of flood risk. (3) The available flood resources in both the wet and dry seasons increase, on average, by 0.83 and 0.81 billion m3, and the flood risk remains within the acceptable range after raising the FLWL by 1.00 m, which contributes to enhancing floodwater utilization.

“…Run theory is commonly used to identify drought events and extract drought characteristic variables [50][51][52][53]. It can be applied to different drought indices, but the selection of the drought event threshold needs to be careful [54].…”

Section: Run Theory and Threshold Methodsmentioning

confidence: 99%

Understanding the Propagation of Meteorological Drought to Groundwater Drought: A Case Study of the North China Plain

Chen,

Zhang,

Tian

et al. 2024

As extreme climate events become more common with global warming, groundwater is increasingly vital for combating long-term drought and ensuring socio-economic and ecological stability. Currently, the mechanism of meteorological drought propagation to groundwater drought is still not fully understood. This study focuses on the North China Plain (NCP), utilizing statistical theories, spatiotemporal kriging interpolation, and the Mann–Kendall trend test to examine the spatial and temporal distribution characteristics of groundwater from 2005 to 2021. Based on drought theory, the characteristics and propagation process of drought are further quantified. Key findings reveal the following: (1) Shallow groundwater depths in the NCP follow a zonal pattern from the western mountains to the eastern plains and coastal areas. Over two-thirds of this region showed an increase in groundwater depth at a rate of 0–0.05 m/a; (2) Groundwater drought frequency typically ranges from 3 to 6 times, with an average duration of 10 to 30 months and average severity between 10 and 35; (3) Delayed effects last between 0 to 60 months, with attenuation effects varying from 0 to 3 and prolonged effects extending from 0 to 16. Additionally, delayed effects intensify with increasing time scales, while prolonged effects weaken. Notably, both delayed and prolonged effects in the north of the NCP are more pronounced than in the south of the region. This study quantifies the process by which meteorological drought propagates to groundwater drought, offering a new perspective for understanding the interaction between groundwater and meteorological drought. It holds significant scientific importance for monitoring drought and managing water resources in the context of global climate change.