Spatiotemporal Evaluation of the Flood Potential Index and Its Driving Factors across the Volga River Basin Based on Combined Satellite Gravity Observations

Self Cite

In the summer of 2022, Pakistan experienced a severe flood event that brought great destruction to the local people and ecosystem. However, there is no comprehensive study on the process, spread and causes of this flood. Therefore, we combined multiple satellite gravity data, meteorological data, hydrological data, and satellite remote sensing data to conduct a thorough investigation and study of this flood. The results show that a 20-year time series of the terrestrial water storage change based multiple gravity data has the high accuracy and reliability, which is used for detecting the flood. The flood propagated through meteorological system (three months), agricultural system (six months) and terrestrial ecosystems (five months), respectively, and the two southern provinces (Balochistan and Sindh) are the most affected by the flood, whose flood severity is 6.955 and 9.557, respectively. The center of the severe flood is located at the border region between the above two province. The severe flood is attributed primarily to the global extreme climate events (La Niña and negative Indian Ocean Dipole events) that altered the transport path of water vapor in the Indian Ocean, causing large amounts of water vapor to converge over Pakistan, resulting in heavy precipitation, and secondarily to the melting of extensive glacier in the mountainous of northern Pakistan as a result of the high temperature in March-May 2022. The above results contribute to the understanding of the mechanism of the impact of extreme climate events on the regional climate, and provide some references for the study of severe floods.

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Evolution Characteristics of 2022 Pakistan Severe Flood Event Based on Multi-Source Satellite Gravity Observations

Cui,

Meng,

et al. 2024

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“…The above meteorological data are investigated mainly through ground-based station and remote sensing techniques. However, the above approaches are not suitable for the fine assessment of the severity and spatiotemporal evolution process of droughts, which is attributed to the sparse distribution of ground stations (ground-based measurement) and the inability to capture complete terrestrial water storage change (TWSC) information (remote sensing) [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Evolution Features of the 2022 Compound Hot and Drought Event over the Yangtze River Basin

Cui,

Zhong,

Meng

et al. 2024

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A rare compound hot and drought (CHD) event occurred in the Yangtze River Basin (YRB) in the summer of 2022, which brought serious social crisis and ecological disaster. The analysis of the causes, spatiotemporal characteristics and impacts of this event is of great significance and value for future drought warning and mitigation. We used the Gravity Recovery and Climate Experiment (GRACE)/GRACE Follow-On (GRACE-FO) data, meteorological data, hydrological data and satellite remote sensing data to discuss the spatiotemporal evolution, formation mechanism and the influence of the CHD event. The results show that the drought severity caused by the CHD event was the most severe during 2003 and 2022. The CHD event lasted a total of five months (from July to November), and there were variations in the damage in different sub-basins. The Wu River Basin (WRB) is the region where the CHD event lasted the longest, at six months (from July to December), while it also lasted four or five months in all the other basins. Among them, the WRB, Dongting Lake Rivers Basin (DLRB) and Mainstream of the YRB (MSY) are the three most affected basins, whose hot and drought severity values are 7.750 and −8.520 (WRB), 7.105 and −9.915 (DLRB) and 6.232 and −9.143 (MSY), respectively. High temperature and low precipitation are the direct causes of the CHD event, and the underlying causes behind this event are the triple La Niña and negative Indian Ocean Dipole event. The two extreme climate events made the Western Pacific Subtropical High (WPSH) unusually strong, and then the WPSH covered a more northerly and westerly region than in previous years and remained entrenched for a long period of time over the YRB and its adjacent regions. Moreover, this CHD event had a devastating impact on local agricultural production and seriously disrupted daily life and production. Our results have implications for the study of extreme disaster events.

“…Global warming and human activities have massive impacts on the terrestrial water cycle and have changed the natural hydrological system, resulting in a significant increase in the frequency of extreme heat, flood and drought events [1][2][3]. Due to these extreme disasters, affected ecosystems are significantly diminished [4,5].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Change in Evapotranspiration across the Indus River Basin Detected by Combining GRACE/GRACE-FO and Swarm Observations

Cui,

Yin,

Zou

et al. 2023

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Evapotranspiration (ET) is an important approach for enabling water and energy exchange between the atmosphere and the land, and it has a very close relationship with terrestrial water resources and the ecological environment. Therefore, it is of great scientific to accurately quantify the spatiotemporal change in ET and its impact factors to understand the terrestrial water change pattern, maintaining water resource security and protecting the ecological environment. Our goal is to study the spatiotemporal characteristics of ET in the Indus River basin (IRB) and their driving factors. In our study, we first integrated the multi-source satellite gravimetry observations using the generalized three-cornered hat and least square methods to obtain the high-precision and continuous spatiotemporal evolution features of ET in the IRB from 2003 to 2021. Finally, we combined nine hydrometeorological and land cover type data to analyze the factors influencing ET. The results indicate that the algorithm used in our study can improve the ET accuracy by 40%. During the study period, ET shows a significant increasing trend (0.64 ± 0.73 mm/a), and the increasing rate presents spatial distribution characteristics of high variability in the northern areas and low variability in the southern areas of the study region. ET has a close relationship with precipitation, specific humidity, total canopy water storage, surface temperature and wind speed (with a correlation coefficients greater than 0.53 and variable importance of projection greater than 0.84). Among these factors, precipitation, specific humidity and surface temperature have significant correlations with ET (correlation coefficients greater than 0.85 and variable importance of projection greater than 1.42). And wind speed has a more significant positive effect on ET in the densely vegetated regions. The impacts of climate change on ET are significantly greater than those of land cover types, especially for similar land cover types. Ice and snow are significantly different to other land cover types. In this region, ET is only significantly correlated with precipitation, specific humidity and snow water equivalent (variable importance of projection greater than 0.81), and the impacts of precipitation and specific humidity on ET have been significantly weakened, while that of snow water equivalent is significantly enhanced. Our results contribute to furthering the understanding of the terrestrial water cycle in subtropical regions.