Spatial-Temporal Characteristics And Disater Risk Assessment Of Climate Extremes In Shenzhen

Shenzhen is a typical city of rapid urbanization in China.Urbanization development has brought population agglomeration and urban expansion,coupled with it is located in the south coast of china.So it is an important research area affected by climate change.The spatial-temporal chracteristics analysis and disaster risk assessment of extreme climate can help to cope with the influences of climate warming,and it has great significiance for the improvement of urban disaster prevention system.Based on the meteorological data of Shenzhen from 1953 to 2015,the change trend of the extreme temperature and extreme precipitation indices had been calculated by RclimDex1.0 software of R language,the time series by the linear trend method and local weighted regression,and the spatial differentiation visualization had been indicated by interpolation software ANUSPLIN.The temporal and spatial changes of the extreme climate indices between 2004 and 2015 were analyzed by using the ArcGIS10.3 platform.Describe the characteristics of extreme winds based on historical weather data.Then,based on the theory of IPCC extreme climate management and the extreme climate cahnge characteristics in Shenzhen for more than 60 years,the risk assessment framework and index system of extreme weather disaster in Shenzhen were constructed.To assess disaster risk of extreme temperature,extreme precipitation and extreme wind disaster,the weights of various disasters had determined by historical disaster data and social attention degree.The main conclusions are as follows:(1)The extreme heat and extreme cold were rising in Shenzhen,and the climate was warming during 1953-2015 and urban warming slow down nearly 10 years based on the results of the curve fitting.The frequency and intensity of extreme precipitation was decreasing,and the duration was increasing significantly.And the impact of extreme precipitation still can not be underestimated in Shenzhen.Extreme heat was high in west while low in east.Regarding extreme precipitation,the northeast was of high frequency and long duration,while northwest was of intensity.From 2004 to 2015,The highest daily maximum temperature is lower in non-mountainous areas,showing significant terrain differences.the frequency of precipitation almost increased throughout the region,the intensity of some areas decreased,duration of non-mountain increased.The extreme winds affecting Shenzhen are most affected by tropical cyclones,and concentrated in the summer.In recent years,the tropical cyclones have a longer impact time,mainly in the coastal areas and highlands,and in some parts of the Longgang area(2)The high risk areas of extreme weather disasters in Shenzhen were on Guangming New District in the northwest,Xinan and Nanshan street in the southwest,central and Longcheng and Kengzi in the northeastern,and parts of the East.In addition to the central regions including Yantian,Kuiyong and Dapeng in east,whose extreme precipitation and extreme wind disaster are main risk,the other high risk value areas' main risk are extreme temperature and extreme precipitation.For Northwest and southwest,Longcheng,Kengzi,Pingshan areas in northeast,high hazard and high degree of exposure is dominant.In Shenzhen central areas,high exposure and high vulnerability are main risk.Kuiyong and Dapeng in east are closer to the sea,with high hazard and high vulnerability.