Research Of Rain Island Effect On Laoshan District Based On GIS And RS

At present, with social and economic development, the urbanization processaccelerated, increasing urban population, with the increase of the city’s buildings,squares and roads. Instead, the green space and water bodies have a correspondingreduction and a high-rise buildings. But with the increases of high-rise density and thepoor air circulation, especially in a midsummer, the building air conditionersautomobile exhuast aggravates the extraordinary emission of heat. It leads of theformation of hot air over the city. At the same time, hot air piled thick and enventuallyleading to the formation of precipitation. The rainfall more concentrated in floodseason and the time of storm. Tt is easy to form a large area of water even formationof a regional urban waterlogging. Modern urban waterlogging has two characteristics:the first is the universality of urban waterlogging. There are different degrees ofwaterlogging phenomenon in many cities of our country. Secondly, the incidence ofwaterlogging is high in some specific locations of our city, such as overpasses. Withthe construction of modern city, the phenomenon of waterlogging often occurs acrossthe street in the underground passage, railway bridge and high bridges. In addition, inrecent years, the phenomenon that many cities’ precipitation was significantly greaterthan the surrounding suburbs has become increasingly prominent and at the same time,it will cause pressure on urban infrastructure.The passage choose laoshan district as study area which is located in the east ofQingdao and near the Yellow Sea in the southeast. On the whole terrain, the southwestand northeast of laoshan district and the southeast coast is main of plains, also in thecentral and southern area is main of mountainous. The area where urban residentsgathered together is main of plains. Summer prevails monsoon winds. The differenceof precipitation between cities and suburbs is particularly evident. So form a clear rainisland effect. The precipitation of mountainous areas that in central and southern,thanks to the terrain, is different from the surrounding areas. On the basis of this, itforms two obvious rain center of island. In view of the important effect, rain islandeffect on the urban precipitation, this paper choose laoshan district as the study areawhere has two rain islands. The results showed that laoshan district has obvious rainisland effect and it has a important effect on the precipitation of laoshan district. (1)The article choose surface parameters, human factors, urbanization, terrain andother factors which can influence the rain island effect to analyse and showed that thesurface temperature of laoshan district has been increasing in recent decades.Population grew by nearly two times. The urban explanation is significant. The degreeof urbanization has a substantial increase. The precipitation is different between plainsand mountains.On the basis to analyse relationship between these factors and the rainisland effect.(2)Article interpretates the rain island effect from three aspects which includecharacterization of precipitation, temperature and wind speed. It reflects the curvesand rules of the three indicators in the flood season of laoshan district. Furtherindicates the presence of rain island effect.(3)To further demonstrate the presence of rain island effect in laoshan district,this passage analyses the temporal patterns of precipitation in laoshan district, withthe analysis of the time pattern changes and spatial pattern changes of rain islandeffect in laoshan district. The results show that, in time the rainfall is more in theflood season. In space, the precipitation of urban is greater than outskirt precipitation.And with urbanization, the difference of suburban precipitation is more apparent.(4)Aiming at the indirect effect that urbanization on the rain island effect, we takelaoshan district of Qingdao as an example. On the basis of the analysis of basictopography, hydrology, climatic condition in laoshan district, we use surfacetemperature inversion, land use distribution, Thiessen polygons, regression analysismethod to analyse the impact that urbanization have on the rain island effect. Theresults show that the increase of temperature and the city precipitation meet the linearregression relationship. So it is clearly that urbanization is an important factor whichcan influence the urban precipitation in laoshan district.(5)Combined the impact that urbanization has on the rain island effect, the articledescribes the measures to deal with the rain island effect. It has an importantsignificance to propel the research of climate change, urban planning, urban floodcontrol and other aspects in laoshan district.