Flood Risk Assessment for Zengcheng District of Guangzhou City Based on Complex Network Models by LI Bowen, ZHANG Yin, YANG Fang, ZHAO Hongjun

“…Under the dual influences of climate changes and urbanization,the frequent urban flood disasters exacerbate losses caused by the flood disaster chain and pose a serious threat to the public life safety and sound development of cities.Based on the disaster data from 1980 to 2020 in the Zengcheng District of Guangzhou,this paper builds a complex network model of disaster evolution by employing heavy rain as the disaster source and conducts disaster risk analysis.The vulnerability of the disaster network is evaluated by the calculation of the network average disaster path,edge betweenness,and connectivity.Meanwhile,the correlation between disaster events is analyzed by the co-occurrence rate of the events.The results show that high-intensity and short-duration heavy rain is the source of flood disasters in Zengcheng District,Guangzhou.Damage to water conservancy facilities is a key node affecting the vulnerability of the disaster network,and inundated farmland is the main cause of significant economic losses,with house flooding caused by water on the road surface being the biggest disaster risk.The results can provide references for risk control of the flood disaster chain in Zengcheng District,Guangzhou,and related emergency management decisions.…”
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Spatial and Temporal Analysis of Ecological Footprint and Ecological Carrying Capacity of Water Resources in Guangzhou by ZHAO Zixi

“…In order to quantitatively analyze the pressure of regional water resources and evaluate the status of sustainable development of water resources.Based on the ecological footprint model of water resources,this paper analyzes the temporal and spatial differences of ecological footprint and ecological carrying capacity in Guangzhou from 2005 to 2019.The results show that the per capita ecological footprint of water resources in Guangzhou is decreasing year by year,the per capita water resources carrying capacity is consistent with the total amount of water resources,and the fluctuation is large.The water resources are in surplus,and the ecological footprint of water resources per 10 000 yuan GDP is decreasing year by year.The water resources account of Guangzhou is in a safe state.The regions with larger ecological footprint of water resources per capita are located in Huangpu and Nansha District,while those in Baiyun,Tianhe and Haizhu District are smaller.The distribution of per capita water resources carrying capacity of each district is:Conghua District>Zengcheng District>Huadu District>Nansha District>Huangpu District>Panyu District>Central District.According to the analysis results,it is suggested that the administrative regions of Guangzhou should upgrade their industries according to the government planning and the actual distribution and utilization of water resources,so as to improve the water use efficiency and realize the sustainable utilization of water resources.…”
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Research and Application of Data-driven Forecast Method for Water Level Increment of Small and Medium-sized Rivers by DING Wu, LIN Hanxiong, WANG Hangang, ZHANG Wei, YANG Bin

“…Focusing on the forecast of flash flood disasters in small and medium-sized rivers,this paper adopts three data-driven forecast models to forecast the maximum water level increment.With Paitan Town,Zengcheng District,Guangzhou City as the research area,the mathematical modeling and accuracy evaluation of the three models are carried out.The analysis shows that the forecast accuracy of machine learning is the highest,but the forecast results are not interpretable.The forecast accuracy of the similarity analysis model is medium,and the prediction results have good cognition and interpretability.The overall prediction accuracy of the “rainfall-water level increment” relationship model is the lowest,but its operation is simple.The calculation of the similarity analysis model and machine learning model is relatively complex,relying on computer-aided calculation,and the results of the “rainfall-water level increment” relationship model can be plotted as graphs.Considering the forecast accuracy and convenience,multiple models such as the machine learning model and similarity analysis model can be applied for the forecast to improve the forecast accuracy if there is support from auxiliary equipment such as computers and mobile phone applications.Without support from computers and other basic equipment,the “rainfall-water level increment” relationship model can provide a convenient forecast method for flash flood forecast and early warning in small and medium-sized rivers.…”
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Risk Assessment and Spatial Migration Patterns of Compound Flood and Derived Landslide Disasters in Guangzhou,China by LI Xiaodi, ZHONG Ming, LI Xueyou

“…Compound floods and derived landslide disasters are frequent in estuaries under the influence of high-intensity localized heavy rainfalls and tidal level top support.This paper proposes a comprehensive method for risk assessment and spatial migration patterns of compound flood and derived landslide disasters.Meanwhile,taking Guangzhou as the study area,it constructs the index system for risk assessment of compound floods and derived landslide disasters in the city.Additionally,the weighted comprehensive evaluation method is adopted to assess the risk of multi-source compound disasters,and the spatial risk distribution pattern of the above-mentioned three types of disasters and the migration law of the disaster risk are explored based on the standard deviation ellipse method.The results are as follows:① 52.81% areas of Guangzhou are medium-high risk and high-risk ones,and the risk of composite floods and derived landslide disasters as a whole presents the characteristics of high risk in the northeast and low risk in the southwest,among which the risk of Conghua District and Zengcheng District is higher.Thus,disaster prevention and mitigation measures should be taken to reduce the disaster risks in the above areas.② The center of gravity of the risk of heavy rainfall flooding-composite flooding-composite flooding and derived landslide hazards first moves to the southwest and then to the northeast,and the disaster risk shows a southwest-northeast distribution pattern,with the first enhanced and then gradually weakened aggregation effect of disaster risks.The results can provide a scientific basis for the risk decision-making of compound disasters and disaster prevention planning.…”
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