Epidemic Characteristics and Spatio-Temporal Patterns of HFRS in Qingdao City,China,2010-2022

Objective This study investigated the epidemic characteristics and spatio-temporal dynamics of hemorrhagic fever with renal syndrome(HFRS)in Qingdao City,China.Methods Information was collected on HFRS cases in Qingdao City from 2010 to 2022.Descriptive epidemiologic,seasonal decomposition,spatial autocorrelation,and spatio-temporal cluster analyses were performed.Results A total of 2,220 patients with HFRS were reported over the study period,with an average annual incidence of 1.89/100,000 and a case fatality rate of 2.52%.The male:female ratio was 2.8:1.75.3%of patients were aged between 16 and 60 years old,75.3%of patients were farmers,and 11.6%had both“three red”and“three pain”symptoms.The HFRS epidemic showed two-peak seasonality:the primary fall-winter peak and the minor spring peak.The HFRS epidemic presented highly spatially heterogeneous,street/township-level hot spots that were mostly distributed in Huangdao,Pingdu,and Jiaozhou.The spatio-temporal cluster analysis revealed three cluster areas in Qingdao City that were located in the south of Huangdao District during the fall-winter peak.Conclusion The distribution of HFRS in Qingdao exhibited periodic,seasonal,and regional characteristics,with high spatial clustering heterogeneity.The typical symptoms of“three red”and“three pain”in patients with HFRS were not obvious.

Study on concentration distribution and detonation characteristics for non-axisymmetric fuel dispersal

The study of non-axisymmetric fuel dispersal and detonation can provide reference for the prevention of industrial cloud explosion accidents and the design of fuel air explosive(FAE).The concentration and detonation fields of 85 kg cylindrical and fan-shaped fuel are investigated by experiments and numerical simulations.A dynamic model of the whole process for fuel dispersal and detonation is built.The concentration distribution of fuel is used as the initial condition to calculate the detonation stage,thus solving the initial value problem of detonation field.The phase and component changes of fuel cloud at different locations are compared.The fuel cloud is divided into directions of 0°,90°,135°and 180°.The results show that the maximum cloud radius is 20.94 m in 135°and the minimum is 12.04 m in 0°.The diameter of the detonation fireball is 53.6 m,and the peak temperature is 3455 K.The highest peak overpressure is 3.44 MPa in 0°and the lowest is 2.97 MPa in 135°.The proportion of liquid phase in 0°is22.90%,and the fuel loss is 11.8% and 9% higher than that in 135°and cylindrical charge,respectively.The stable propagation distance of blast wave in 135°is 42.50% longer than 0°and 28.37% longer than cylindrical charge.

Characteristics and distribution of microstructures in high pressure die cast alloys with X-ray microtomography:A review

Al and Mg alloy high pressure die castings(HPDC)are increasingly used in automotive industries.The microstructures in the castings have decisive effect on the casting mechanical properties,in which the microstructure characteristics are fundamental for the investigation of the microstructure-property relation.During the past decade,the microstructure characteristics of HPDC Al and Mg alloys,especially micro-pores andα-Fe,have been investigated from two-dimensional(2D)to threedimensional with X-ray micro-computed tomography(μ-CT).This paper provides an overview of the current understanding regarding the 3D characteristics and formation mechanisms of microstructures in HPDC alloys,their spatial distributions,and the impact on mechanical properties.Additionally,it outlines future research directions for the formation and control of heterogeneous microstructures in HPDC alloys.

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab quality.In order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT software.Results show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either side.As the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes uneven.Although increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

Spatial and Temporal Distribution Characteristics of Snowstorm in Ulanqab City in Recent 30 Years

Based on the data of daily snowfall and weather phenomena of 11 national meteorological stations in Ulanqab City from 1991 to 2020,the spatial and temporal distribution characteristics of snowstorm were analyzed.The results show that the snowstorm in Ulanqab had obvious seasonal distribution characteristics,mainly happening in spring(March-May)and autumn(September-November).It also had obvious regional distribution in space,and the snowstorm center appeared in Chahar Right Wing Middle Banner and Jining District,namely the east side of the Yinshan Mountain.In the past 30 years,the amount of snowstorm in the whole year in Ulanqab showed a certain fluctuation trend,and the number of snowstorm days had shown an obvious upward trend since 2011.

Species and Distribution Characteristics of Alien Invasive Plants in Garden Greenbelt of Shijiazhuang City

[Objectives]The paper was to investigate the garden greenbelt in 30 sample plots such as parks,roads,communities,etc.in Shijiazhuang City.[Methods]The species,abundance and frequency of weeds in the greenbelt of public gardens were recorded through point-line-surface investigation,and typical plants were sampled.[Results]There were 56 species of alien invasive plants in garden greenbelts of Shijiazhuang City,belonging to 44 genera and 20 families.In terms of life form,herbaceous plants were absolutely dominant,accounting for 92.8%of the total.The most alien invasive plants were native to America,accounting for 66.1%of the total.In terms of introduction path,the plants introduced artificially and unintentionally accounted for almost half.The species and quantity of alien invasive plants were related to the size of greenbelt area,the length of the build time of the surveyed plot,the composition structure of greenbelt and the level of green management and protection.There was larger distribution of alien invasive plants in the sample plots with large greenbelt area,long build time,herbaceous-dominated greenbelt and low level of green management and protection.Among the 56 alien invasive plants,3 plants were toxic.From the perspective of invasiveness,the alien invasive plants in the garden greenbelt of Shijiazhuang City could be divided into 5 levels:invasive alien species of malignant consequences,invasive alien species of severe consequences,invasive alien species of partial consequences,invasive alien species of average consequences,and invasive alien species to be observed.[Conclusions]This study will provide a reference for the prevention and control of alien plant invasion,and lay a foundation for the prevention and control of existing invasive plants.

Distribution Characteristics and Shielding Effects of Ion Clouds

The latest research shows that the ions generated by the corona discharge of lightning rod have dual functions of attracting and shielding lightning discharge. After the lightning rod is installed at a certain height on the ground,the lightning rod tip reaches the corona threshold to ionize the surrounding air and generate positive and negative ions under the action of the electric field at the end of the lightning downward leader. Constrained by Coulomb’s Law,its positive ions( opposite charges attract each other) form an upward leader( streamer),which moves towards the end of the lightning downward leader and is connected to the downward leader,establishing a discharge channel to attract lightning to the needle tip and discharge the current to the ground,and playing a role in attracting lightning. Its negative ions are repelled by the electric field at the end of the lightning downward leader( repelled by isotropic charges) and influenced by the wind,and diffuse in the downwind area to form an ion cloud,inhibiting the growth of corona at the tip of ground objects,and playing a role in shielding lightning. In this paper,Franklin’s understanding of the role of lightning rod and Yang Shaojie’s new definition of the working principle of lightning rod are briefly introduced. The formation mechanism,distribution characteristics,shielding effect,and impact on lightning strike point distribution of ion clouds are analyzed. Additionally,the important role of shielding effects of ion clouds in regional lightning protection is introduced,which provides a theoretical basis for the correct understanding and use of lightning rod.

Numerical analysis of the effects of vesicle distribution characteristics on the engineering properties of volcanic rocks

Vesicles can be of different sizes and shapes and can be randomly distributed within vesicular volcanic rocks. This study investigates the variation of engineering properties of vesicular rocks due to the changes in vesicle distribution characteristics for different cases of bulk porosity and vesicle diameter using a systematic numerical simulation program using the finite element method-based rock failure process analysis (RFPA) software. Models with uniform-size vesicles and combinations of different proportions of different-sized vesicles were considered to resemble natural vesicular rocks more closely, and ten different random vesicle distributions were tested for each case. Increasing bulk porosity decreased the uniaxial compressive strength (UCS) and elastic modulus of the specimens, and the specimens with the lowest bulk porosity showed the greatest range of UCS values in the case of uniform-size vesicles. The effect of vesicle diameter on UCS showed an unsystematic response which was understood to be a result of different vesicle distribution patterns, some of which facilitated a shear failure. Specimens with multiple-size vesicles in different proportions revealed that the variation of UCS due to vesicle distribution characteristics is minimum when the bulk porosity is equally shared by different size vesicles. In addition, when the proportion of smaller-sized vesicles is higher, UCS showed an increase compared to that of the equal proportion of different size vesicles case at low porosities, but a decrease at higher porosities. Variation of elastic modulus showed minor, unsystematic fluctuations as a function of vesicle diameter and different proportions of different-sized vesicles, and the range for different vesicle distribution patterns was narrow in general. Overall, the findings of this study recommend cautious use of the engineering properties determined through a limited number of laboratory tests on vesicular rocks.

Enrichment conditions and distribution characteristics of lacustrine medium-to-high maturity shale oil in China

Successful breakthroughs have been made in shale oil exploration in several lacustrine basins in China,indicating a promising future for shale oil exploration and production.Current exploration results have revealed the following major conditions of lacustrine shale oil accumulation:(1)stable and widely distributed shale with a high organic abundance and appropriate thermal maturity acts as a fundamental basis for shale oil retention.This shale exhibits several critical parameters,such as total organic carbon content greater than 2%,with optimal values ranging from 3% to 4%,kerogen Ⅰ and Ⅱ_(1) as the dominant organic matter types,and vitrinite reflectance(R_(o))values greater than 0.9%(0.8% for brackish water environments).(2)Various types of reservoirs exhibiting brittleness and a certain volume of micro-nanoscale pores are critical conditions for shale oil accumulation,and these reservoirs have porosities greater than 3% to 6%.Moreover,when diagenesis is incipient,pure shales are not favorable for medium-to-high maturity shale oil enrichment,whereas tight sandstone and hybrid rocks with clay content less than 20% are favorable;however,for medium-to-late-stage diagenesis,pure shales with a clay content of 40% are favorable.(3)The retention of a large amount of high-quality hydrocarbons is the factor that best guarantees shale oil accumulation with good mobility.Free hydrocarbon content exceeding a threshold value of 2 mg/g is generally required,and the optimum value is 4 mg/g to 6 mg/g.Moreover,a gas-oil ratio exceeding a threshold value of 80 m^(3)/m^(3) is required,with the optimal value ranging from 150 m^(3)/m^(3) to 300 m^(3)/m^(3).(4)High-quality roof and floor sealing conditions are essential for the shale oil enrichment interval to maintain the overpressure and retain a sufficient amount of hydrocarbons with good quality.Lacustrine shale oil distributions exhibit the following characteristics:(1)major enrichment areas of shale oil are located in semi-deep to deep lacustrine depositional areas with external materials,such as volcanic ash fallout,hydrothermal solutions,and radioactive substances with catalytic action,as inputs;(2)intervals with“four high values and one preservation condition”govern the distribution of shale oil enrichment intervals;and(3)favorable assemblages of lithofacies/lithologies determine the distribution of enrichment area.According to preliminary estimates,China has 131×10^(8) to 163×10^(8) t of total shale oil resources with medium-to-high thermal maturity,among which 67×10^(8) to 84×10^(8) t is commercial.These resources are primarily located in the Chang 7^(1+2) interval in the Ordos Basin,Qing 1+2 members in Gulong sag in the Songliao Basin,Kongdian and Shahejie formations of Cangdong sag,Qikou sag and the Jiyang depression in the Bohai Bay Basin,and Lucaogou Formation in the Junggar Basin.

Study on Distribution Characteristics and Occurrence Form of Soil Fluorine in Sorghum Base of Renhuai City

In order to find out the effects of soil fluorine on ecological environment and crop safety in the sorghum cultivation base of Renhuai City, Guizhou Province, the content and the occurrence forms of soil fluorine and its influencing factors of Maoba Town were investigated and studied. The results showed that the total fluorine content in the soil of the sorghum base ranged from 668.60 to 2 596.80 mg/kg, with an average of 1 483.25 mg/kg, which was 3.10 and 1.85 times of the national soil background value and the average value of the soil in endemic areas, respectively. The spatial distribution of fluorine in the soil of the study area was uneven, and the fluorine content was in the order of Anliang Village>Yangliu Village>Houba Village>Xiongfeng Village. The soil fluorine contents of various forms varied greatly, and the distribution law was as follows: residual state>water soluble state>organically bound state>exchangeable state>Fe/Mn-F state. The residual fluorine content was the highest, accounting for more than 99% of total fluorine content, while the sum of other four forms was less than 1%, with their respective proportions ranging from 0.10% to 0.30%. The content and proportion of available fluorine in water-soluble and exchangeable states were relatively low, which had limited influence on the surrounding water environment and crop safety. The physicochemical properties of soil, such as pH, organic matter, cation exchange capacity and clay particles had a certain influence on the occurrence forms of soil fluorine, thus changing the availability and migration of soil fluorine, which might endanger the ecological environment safety, food safety and human health.

Fine Root Distribution Characteristics of Populus cathayana Plantations at Different Ages in Alpine Sandy Land

[Objectives]The paper was to study the fine root distribution characteristics of Populus cathayana plantations at different ages in alpine sandy land.[Methods]With 5,10,15,20,and 25 years old P.cathayana plantation in the eastern margin of Gonghe Basin,Qinghai Province as the research objects,fine roots were collected by root core drilling method,and the differences of fine root biomass,root length density,average diameter and root tip number at the soil depths of 0-20,20-40,40-60,60-80 and 80-100 cm were analyzed.[Results]The total biomass density of P.cathayana plantation was mainly distributed in the soil layer of 0-60 cm,accounting for 76%of the entire soil layer,and its value increased with the increase in forest age.With the increase in different forest ages,the root length density,average diameter and root tip number of living fine roots in the soil layer of 0-60 cm accounted for 74%-81%of the entire soil layer,and the proportions in the soil layers of 60-80 and 80-100 cm were 9%-11%.The biomass density,root length density,average diameter and root tip number of living and dead fine roots of P.cathayana plantation increased with the increase of forest age.The root length density,average diameter and root tip number of P.cathayana fine roots showed a linear function change trend with the growth of forest age,which could be described by the linear function equation y=ax+b(a>0).The analysis results showed that the root length density,average diameter and root tip number of P.cathayana were significantly correlated with the total biomass density of fine roots,and the root length density and average diameter had an extremely positive correlation with the total biomass density.[Conclusions]In the future,P.cathayana plantation should be properly tended to promote the development of fine roots and maximize its ecological benefits.

Spatio-temporal distribution of net primary productivity along the northeast China transect and its response to climatic change

An improved Carnegie Ames Stanford Approach model （CASA model） was used to estimate the net primary productivity （NPP） of the Northeast China Transect （NECT） every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 （P 〈 0.01）. The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 （P 〈 0.01）. The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer （June to August） accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature.

Studies on Distribution and Chemical Characteristics of Copper in Cells of Setcreasea purpurea Boom

[Objective] The aim of this study was to reveal the mechanism of Cu2+ hyper-accumulator in Setcreasea purpurea Boom from the angle of distribution characteristics and binding form of Cu2+ in tissue cells.[Method]The distribution characteristics of Cu2+ in subcells of Setcreasea purpurea Boom was studied by the technique of differential centrifugation,and the binding form of Cu2+ in roots and leaves of Setcreasea purpurea Boom was also investigated by the sequential chemical extraction method and the enzymolysis method.[Result]Cu2+ in roots mainly distributed in the cell wall which is accounting for one third of the Total Cu2+ in roots,while Cu2+ in leaves mainly distributed in the chloroplast which is accounting for a quarter to the Total Cu2+ in leaves.Under the high concentration of Cu2+ or the extended treatment duration,the translocation of Cu2+ in root cells into the cell wall increased but the translocation of Cu2+ in root cells into the plastid decreased,while the translocation of Cu2+ in leaf cells into the chloroplast increased but the translocation of Cu2+ in leaf cells into the cell wall decreased.Cu2+ in leaves was mainly combined with amino acid,small molecular polymeric pigments,protein and polysaccharide,while Cu2+ in roots was mainly combined with cell wall substances such as cellulose and membrane-bound protein.[Conclusion]The distribution characteristics and binding form of Cu2+ in cells is possibly one of the dominant mechanisms for Cu2+ hyper-accumulator in Setcreasea purpurea Boom.

Study on Distribution Characteristics of Lightning Disasters in Hebei Province

Based on the special landscape and regional characteristics,the lightning location information from 1999 to 2008 and conventional observation data from 1971 to 2000 provided by electricity departments in Hebei Province were applied to analyze spatial and temporal distribution of lightning.With lighting disaster data since 2000 provided by meteorological department,and records from civil affair,statistics,insurance,and other departments,the lighting disaster distribution of Hebei Province was studied from aspects of economic and people losses,and some countermeasures for several lightning disasters industries were put forward.

Distribution Characteristics of COD in the Waters of Pearl River Estuary

The surveys on the COD in the Lingdingyang waters of Pearl River estuary were carried out in May and August of 2002. The results showed that the concentrations of COD in the waters ranged from 0,41 to 2.72 mg·L^-1 with an average of 1.21 mg·L^-1.The spatial distributions showed that COD concentration decreased gradually from the north to south of Pearl River estuary, and the concentration near coastal waters was higher than that in offshore waters. The concentration of COD in summer was higher than in spring. Evaluated by the first class （COD ≤ 2 mg·L^-1） of sea water quality standard （Chinese standard）, there were about 15 % of COD concentrations over the standard. The concentration of COD showed a positive correlation with the concentration of suspend substances in spring and summer, but in summer it showed a negative correlation with the concentrations of inorganic nitrate and phosphate.

Vertical Distribution Characteristic of Nitrogen in the Core Sediments of Three Rivers Estuary in Poyang Lake

The vertical profile distribution characteristics of nitrogen in core sediments of Three Rivers Estuary in Poyang Lake were studied.The results showed that TN content in core sediments ranged from 480.0 to 1 900.0 μg/g with the change of depth,which was divided into three distribution types as follows:TN content decreases gradually with the increase of depth,TN content increases gradually with the increase of depth or higher content in the middle but lower content in two ends.NH4+-N content ranged from 8.7 ...

Quantitative Study on Characteristics of the Weibull Distribution

Aim To quantitatively study three characteristics of the Weibull distribution. Methods Theoritical analysis of the three characteristics of parameters of the Weibull distribution was done and mathematics software was used to make some chart analysis. Results 17 equations and 7 figures were made. Conclusion Under the standard form, the class of the Weibull probable density founction(pdf) curves appear double peak shape. Under the standard form, the maximum value point curve of the Weibull pdf takes line t =0 and t=1 as asymptotes. When β = 3 30-3 40, the Weibull distribution is the most similar to the normal distribution.

Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, China

In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corresponding rise. In terms of spatial distribution, the rainfall-triggered landslides primarily occurred in the northeastern part of the study area, particularly in regions characterized by complex topography such as Shanzao Village in Yantan Town, Xixia Township, and Shangzhang Township. The research findings offer crucial data on the rainfallinduced landslides triggered by Typhoon Lekima, shedding light on their spatial distribution patterns. These findings provide valuable references for mitigating risks and planning reconstruction in typhoon-affected area.

Distribution characteristic and variation trend of planktonic dinoflagellate in the Taiwan Strait from 2006 to 2007

Based on 4 cruise surveys from July 2006 to October 2007 in the Taiwan Strait, the species composition, community structure and spatio-temporal distribution of dinoflagellate were studied. A total of 131 dinoflagellates belonging to 18 genera were identified. The population was dominated by hyperthermal and hyperhaline species accounting for 72.52% of the total species. Eurythermal and euryhaline species were the second most common one accounting for 25.19% of the total species. It was only 2.29% for neritic species. The maximum species number occurred in summer, while the maximum cell density appeared in spring. The average dinoflagellate cell density was 404.96x104 cells/m3. It showed that the dinof]agellate cell density increased from the nearshore waters to the open sea and from the north to the south. Compared with the results during 1984-1985, the horizontal distribution pattern and seaeonal variation of the dinofiagellate have not changed significantly, but the dinoflagellate cell density increased by 3.01 times. Further analysis of the dinoflagellate abundance variations both in the spatial and temporal aspects, indicated that the abundance of dinoflagellate increased more significantly in cold seasons, and there was a larger increase in the north of the Taiwan Strait. Besides, the dinoflagellate community structure changed notably. It showed that the diversity and evenness index were relatively high, and the proportion of dinoflageliate cell density to the total phytoplankton increased.

Analysis on Spatio-temporal Distribution of Lightning in Dalian Area of China between 2007 and 2008

The cloud-to-ground lightning data between 2007 and 2008 were collected by lightning detection and location system,which was composed of four lightning detectors in four different sites of Dalian area.The spatio-temporal distribution of cloud-to-ground lightning in surrounding areas of Dalian was analyzed from several aspects of polarity distribution,diurnal variation,lightning intensity and lightning density.The results showed that the number of negative lightning accounted for 93.9% of the total number of lightning,and its average lightning intensity was 27.99 kA.The number of positive lightning accounted for 6.1% of the total number of lightning,and its average lightning intensity was 35.56 kA.The diurnal variation of lightning frequency showed an obvious structure of two peaks (17:00-18:00 and 04:00-05:00) and two valleys (09:00-10:00 and 00:00-01:00).The number of lightning between May and September was 91.5% of the annual number,and the lightning occurred the most frequently between June and August.Most of positive and negative lightning was at the intensity of 15-35 kA,80.0% lower than 40 kA,and 99.3% lower than 100 kA.The lightning density had obvious regional differences in distribution,high in the Liaodong Bay and the Dalian Bay and low in inland areas.Therefore,coastal areas should attract more attention in lightning disaster defense in the surrounding areas of Dalian.