The Basic Research For The Assessment And Control Method Of The Natural Disaster Risk In Coastal City

Now the intensity and frequency of natural disasters the global suffered isincreasing，disasters such as droughts, floods, hurricanes, earthquakes and tsunamisarc causing great loss in human society. Cities are the largest area affected by thenatural disasters. In all cities, the coastal cities are the core area of the populations,wealth and technology and they are more prone to be suffered by natural disasters. Soit is particularly necessary to study the method of the natural disaster risk assessmentand risk control for the coastal cities. So in this paper, the method of natural disasterrisk assessment and risk control for coastal city is regarded as the research object. Themain contents include the following aspects in this paper:(1)Study on the method for the natural disaster’s level classification of thecoastal city.This paper puts forward a new method using the pattern recognitiontheory combined with multiple indexs evaluating method to classify the level of thecoastal city’s natural disaster level. It is a multiple index pattern recognition method.Through the study we found that the multiple index level classification problem of thecoastal city’s natural disaster level can be simplified into a pattern recognition matterwith multiple input and a single output. Therefore, this paper establishes a lineardiscriminant function to classify the city’s disaster level. In order to calculate thecoefficient of the linear discriminant function, this paper use a fixed incrementalgorithm programming the computation module with the storm surge disaster data. Ithad realized fast calculation of the discriminant function coefficients and achieved thetarget of the classification of the coastal city’s natural disaster level.(2)Study on the risk prediction method for the natural disaster in coastal city. Inthis paper, we found that the natural disaster itself has the characteristics of chaosthrough the study. And the chaos theory can explain the chaotic phenomena exhibitedby natural disasters well. At the same time, chaos theory can also be used to predictfuture development of the natural disasters. Therefore, this paper puts forward anatural disasters risk prediction model based on chaos theory. Through the study wefound that the disasters risk prediction model based on chaos theory can be used toforecast the natural disaster and achieved a good result. On the other hand, this paperalso presented a multiple index risk level prediction model using the neural networktheory in the aspect of the prediction of the natural disasters risk level. Taking thestorm surge disaster for example, through the analysis of the example we can provethat the neural network model can accurately predict the natural disasters risk levelwell based on the main factors of the disaster were identified.(3) Study on the risk quantitative assessment method for the natural disaster incoastal city. Taking the surge disaster and earthquake disasters as an example, thispaper built a risk quantitative assessment model. In the storm surge disaster’s riskquantitative assessment model, this paper discussed the building of the loss rate computing model for the single hazard bearing body and the industry disaster bearingbody, and studied the summary statistics model for the city’s losses caused by thestorm surge disaster. In the earthquake disaster risk quantitative assessment model,this paper put forward a factors influencing damage assessment method for the singlebuilding based on the seismic intensity and a loss evaluation method for the groupbuildings based on the historical disaster data statistics. And in the end we havestudied the summary statistics model for the city’s earthquake disaster losses.(4) Study on the risk spatial visualization assessment method for the naturaldisaster in coastal city. In this paper, we used the GIS technology to conduct visualsimulations for specific disasters, and assess the loss of the disaster based on thedivisions as the regional assessment unit. This paper also took the surge disaster andearthquake disaster as examples to conduct the risk visual assessment. In the processof the visual assessment for the storm surge disaster risk, the paper used a gridcomputing model in GIS to simulate the scope and the water depth distribution rangeof the storm surge, finally realizing the storm surge disaster automatically lossassessment module by programming, then carried on the example analysis. In theprocess of visual assessment for the earthquake disaster risk, This article had studiedthe research data of the seismic intensity attenuation model and then draw theinfluence areas of the earthquake in the map using the GIS technique. Then wecombined with the quantitative statistical model of the earthquake disaster to assessthe casualties, economic loss, building damages of the study area. Finally compilingcomputer programs to simulate the losses caused by the earthquake disaster in thestudy area, and achieved better results.(5) Conducting a visual simulation and risk assessment for the natural disasters inQingdao area. Taking Qingdao city as the study area, this article firstly predicts thestrength of the disasters the region may be suffered in the future through the analysisof the historical disasters in the area. On this basis, the paper conducted a storm surgeand an earthquake disaster risk assessment using the quantitative and visualassessment methods. Combined with the GIS technology, we simulated the effect ofdisasters in the region, added up the disaster losses of the communities in Qingdao,marked the disaster risk of the areas on the map, and generated the destructionthematic maps for the hazard bearing bodies of various types.(6) Study on the risk control method for the natural disaster in coastal city. Thisarticle established a natural disaster warning and emergency information system forthe coastal cities, and took the information system as the primary risk control methodfor natural disaster in the coastal cities. The information system had been developedon the ArcGIS Server platform. The article discussed the system’s logical structuredesign, functional design and database design. And then studied the key technologiesand the realization of the core functionality, established the natural disaster riskcontrol information system for the coastal city. Practice proved that it can play a gooddecision-making role in the coastal city.