The Spatial-temporal Differentiation And Risk Assessment Of Natural Disasters In Guangxi Beibu Gulf Economic Zone

With the global climate changed and activities of human, thegreenhouse effect and stack effect of urbanization is increasinglyoutstanding, global natural disasters are terrifying and becoming aserious threat for human survival. Especially the sea-land transitionzone are faced with the risk of natural disasters, and the increasingof exposure of hazard-affected body. Once those suffered from naturaldisasters, the risk of loss will increased. So the topic of sea-landtransition zone of natural disaster risk research draw the extensiveattention of the international communities, and became the one of thehot issue and international disaster research concern. The analyze ofthe sea-land transition zone of natural disasters and natural disastersystem, and structure of the disaster risk assessment system and mechanism,provide the basis for further carrying out disaster prevention andmitigation work.Natural disaster is the interaction between the earth surfacevariation system which caused by three kinds of factors: subsquentlyenvironment, hazard-affected bodies and disaster-causing factors. Thenatural disaster risk assessment is rearch for the assessment of hazard-formative factors, subsquently environmental vulnerability and riskexposure and vulnerability of hazard-affected bodies respectively. Firstof all, My rearch is based on historical data record, including the naturaldisasters in time and space differentiation of the beibu gulf economiczone. Then based on the research of the natural disaster risk assessmentsystem, choosing to intensity and frequency of risk factors to causean indicator;Futher more, picked Terrain factor risk level, drainagedensity, vegetation coverage, and years of average rainfall forsubsquently environmental vulnerability index; Selected populationdensity of the economy, GDP per capita (GDP), the percentage per unit area of crops and the number of one hundred beds as indicators of exposure-the vulnerability of hazard-affected bodies, set up flood disasterrespectively, drought disaster, tropical cyclone disaster index system,calculation of all kinds of disaster risk, finally integrated naturaldisaster risk of the beibu gulf economic zone.The beibu gulf economic zone is complex that affected by monsooncirculation more weather system, and the unique ecological environmentof sea and land transition zone, lead to the disasters happened frequentlyof the beibu gulf economic zone. From the perspective of the analysisof past disasters, the beibu gulf economic zone of rainfall mainlyconcentrated in April to September, rainfall is large, including flooddisasters. And in March to November, the beibu gulf economic zone accountsfor some23%of the annual rainfall, drought, severe autumn chill. Fromthe point of view that historical disaster statistics, the Shangsi,QinZhou, Yulin, Pubei and most of the coastal areas were attacked byfloods frequently; Due to uneven distribution of rainfall, the waterresources regulation ability in Yulin and QinZhou is pianissimo,frequency of drought disaster. And the beibu gulf economic zone due tothe geological structure is relatively stable, earthquake frequency isnot that high and the strength is weak, with few and focal small shallowearthquake zone.The natural disaster risk distribution of the beibu gulf economiczone present high trend in the East and opposite trend in the West,disaster risk concentrated in the eastern developed areas. Off the coastof the cities such as Hepu, QinZhou, and Yulin are on the high side ofthe natural disaster risk index of the beibu gulf economic zone, whilein the west, as Mashan, Longan, Daxin, Pingxiang and other cities, gota low disaster risk of natural disaster risk index.