Researches On The Urban Heat Island Effect Of Hangzhou Bay

Hangzhou Bay, as the forefront of urban development areas of China, regional -economic development caused the urban heat island issues, as climate problems can not be ignored. Urban heat island (UHI) effect is an important climate impact caused by urbanization. How the urban heat island effect develop with the emergence of urban agglomeration. This is a paper studying the urban heat island effect on Hangzhou Bay.According to the observing temperature data of conventional weather station, 4 remote sensing image taken by Landset-5 TM on Hangzhou Bay, and the corresponding GIS data, study the temporal variation characteristics during 37 years and spatial distribution of urban heat island on Hangzhou Bay. According to the remote sensing image and GIS data define the area of the urban right now and in the future, using the global reanalysis meteorology data of NCEP/NCAR, select the Hangzhou Bay as the study region, using WRF model, running 4 tests as the expansion of urban agglomeration, simulate the UHI effect on Hangzhou Bay, getting the monthly average data by calculating the result of the simulation.The result shows that the UHI effect enhanced remarkably in the Hangzhou Bay during discussing time, and the UHI intensity had been intensified at a ratio of 0.13℃per 10 years. In the 3 of the main cities around the Hangzhou Bay, the UHI effect is the most strong in Hangzhou area, Shaoxing area followed, and the weakest in Ningbo area. The UHI intensity spatial characteristics show that the UHI intensify in Shaoxing area is stronger than another study area, Hangzhou area followed, next to Ningbo area. The result of simulation with WRF model shows: As the urban agglomeration growing, the isograms of average temperature through the day have a high-value area around Hangzhou, Jiaxing and Shanghai, and the high-value area is growing as the urban agglomeration-does. The isograms of average temperature in the day-time have the same situation as that through the day. The isograms of average temperature in the night are expansion as the urban agglomeration does, appear a high-value area on the west and the east of Hangzhou. In the case of wind field, there is a significant change around Hangzhou and shanghai in the day. In the night, there is a wind speed and direction change around Hangzhou, Shaoxing, and Ningbo which are on 30.2°N. There is an increasing trend of precipitation.