The Research On Urban Heat Island Effect Of The Transboundary Area In The Tumen River From 2003 To 2016

The transboundary area in the Tumen River is located in the northeast part of Asia and steps over the China,North Korea and Russia.It is an important constituent part in the international big pathways of "China,Russia,North Korea and Monsolia" under the Belt and Road Initiative and also the key area of developing the Russian Far East and Rason special economic zone.As a result,timely and accurately quantify time-space pattern of urban heat island effect of the transboundary area in the Tumen River shows the important significance on improving mankind well-being and promoting regional urban sustainable development.Unfortunately,there are still lack of relevant studies on the urban heat island effect of the transboundary area in the Tumen River.For this reason,Surface Urban Heat Island Intensity(SUHII)was used as the key index to represent urban heat island effect in this paper.Based on Landsat image,regional land information data and MODIS LST data products were extracted to analyzed time-space pattern of SUHII of the transboundary area in the Tumen River from 2003 to 2016.Also,the impact of regional urban heat island effect was evaluated.Main research results were stated as follows.(1)The spatial pattern of SUHII in 2016 was quantized.Based on MODIS LST data products in 2016,Landsat 8 OLI image was used to extract the urban land information in 2016.The spatial pattern of SUHII in 2016 in the research area was quantized from the perspectives of China,North Korea and Russia.The findings indicated that the average value of SUHII in 2016 was about 0.98?.SUHII in summer was obviously higher than other seasons.SUHII in the daytime was obviously higher than the night.SUHII in China was obviously higher than that of North Korea and Russia.China,North Korea and Russia had an obvious difference in SUHII of four seasons.(2)Influence factors of SUHII in 2016 were analyzed.Suburb NDVI difference value,suburb White-sky Albedo(WSA)difference value,DEM,distance from the seaside,urban land area,total urban population,urban population density and urban night lamplight(8 variables)were used as influence factors.By using a city as the basic analytical unit,the relationship between SUHII and influence factors in different seasons and time areas was quantized.Pearson correlation coefficient and Spearman correlation coefficient were respectively used to quantize the relationship between SUHII and influence factors in different seasons and time areas.The findings indicated that SUHII in summer and winter was irrelevant of these influence factors.SUHII in the daytime and at night was also irrelevant of these influence factors.SUHII in China,North Korea and Russia was significantly relevant of NDVI,WSA,urban land area,total urban population and urban night lamplight intensity.The correlation analysis results indicated that the urban scale was larger,the social economic development was higher,urban vegetation cover was lower and urban heat island intensity was higher.(3)The dynamic changes of SUHII from 2003 to 2016 were analyzed.SUHII in the daytime and at night from 2003 to 2016 had the obvious rising trend.The Stable Urban Area(SUA)and Urbanized Area(UA)in the daytime had the consistent variation trend,but temperature change of SUHII in SUA was higher than UA.In four seasons,SUHII in winter in SUA was on a declining curve,while other seasons were present in the rising trend.The Area of the Surface Urban Heat Island(AreaSUHI)in the daytime was obviously higher than AreaSUHI at night.AreaSUHI in summer in the daytime was decreased for about 0.7 km2,while AreaSUHI at night was increased for about 0.9 km2.It was present in the rising trend in China and Russia.AreaSUHI in China in the daytime was higher than other two sides.In four seasons,AreaSUHI in China was higher than North Korea and Russia.(4)The influence factors of SUHII from 2003 to 2016 were analyzed.SUHII in summer in SUA of China was related to NDVI,total urban population and urban population density.SUHII in summer in SUA of North Korea was related to NDVI and urban population and that of Russia was related to DEM.In 2003-2016,SUHII in summer in UA of China was linked with NDVI and urban population density.That of North Korea was linked with WSA,distance from seaside,and urban land area.SUHII in summer in UA of Russia was linked with NDVI,DEM,total urban population and urban population density.In 2003-2016,SUHII in winter in SUA and UA of China was related to WSA and that of North Korea was relevant of WSA.In winter,SUHII in SUA of Russia was relevant of DEM,urban population density and night lamplight intensity.SUHII in winter in UA of Russia is connected with distance from seaside and total urban population.(5)The possible influence of SUHII from 2003 to 2016 was evaluated.Based on maximum temperature,high-temperature days,average annual precipitation,frost-free season days,annual snowfall days,population changes of children and old people,and residents' heat island effect perception,the impact of SUHII on urban climate,environment and human health was evaluated.The research results indicated that cities of China were present in the growth trend in maximum temperature,high-temperature days,average annual precipitation and frost-free season days in summer,while average annual snowfall days were present in the decline trend.Through the interview and questionnaire on Yanji residents and death data analysis of Yanji disease control prevention center,the findings indicated that the urban heat island effect was an important factor to affect health.