The Influence Of LUCC On The Land Surface Temperature In Yangtze River Basin

Land surface temperature(LST)is a very important parameter in Geoscience,plays a very important role in the interaction of terrestrial environment.It is a key parameter in the study of global change,has great significance to the research of hydrology,ecology,environment and biogeochemistry.This paper,taking the Yangtze River Basin as the research area,uses the MODIS image and the LUCC data as the base data,uses the split window algorithm to inverse LST through the MODIS image,and verifies the credibility of LST.And,the statistical analysis method is used to explore the change characteristics of annual and monthly LST on the time axis.Then,spatial analysis,histogram and other methods were used to study the numerical and spatial distribution of LST in four seasons,such as day-cold,day-hot,night-cold,night-hot.Finally,the influence of land cover and its change,surface morphology,climate,social economy on the surface temperature and its change in the four seasons are discussed with histogram,scatter plot,curve fitting.The difference of the influence with each factor on the surface temperature in different seasons is analyzed,and the driving machine of LST change is summarized.Research and analysis drew the following conclusions:(1)There is a spatial and numerical difference between LST and air temperature(Tair).The daytime LST are higher than Tair,while the night LST is lower than Tair,and the difference between LST and Tair in the high altitude region is larger,while it is small in the low altitude region.It has the stability of spatial distribution and numerical distribution.So the LST is deeply credible.(2)The average range of daytime LST in the Yangtze River Basin is between 5~30 degrees and-5 to 20 degrees at night,and the change trend of LST has a obvious "inverted V type" distribution.At the same time,the standard deviation of monthly daytime LST is between 4~7 and 8~11 at night.The difference between the annual average LST and the standard of different seasons is smaller,and it is obvious that the standard difference of daytime LST is smaller than that of the night.The difference of LST between the different regions in the Yangtze River Basin is less than that of the night.(3)The daytime LST histogram in the Yangtze River Basin is quite different from that of the night.The daytime LST histogram has the similar normal distribution characteristics.When the daytime changes to the night,the LST in some regions decreases rapidly,forming the low temperature fluctuation at night,and the LST drops slowly in some regions,forming a stable middle temperature area,and the LST drops very slowly in some areas,forming high temperature fluctuation.(4)The LST histogram curves of the hot and cold seasons in the Yangtze River Basin are similar,but the spatial distribution of LST varies greatly,and LST spatial distribution of the cold season shows a obvious latitude distribution.In the daytime,the LST standard difference is small and the standard difference is large in the night.Its spatial distribution is that,in the daytime,the LST difference is small between the high altitude regions and the low altitude regions in the Yangtze River,but that is large at night.(5)The surface morphology has a significant influence on the LST.In the night-hot season altitude has a significant linear relationship with the LST.However,the linear relationship is weakened in the daytime by the influence of solar radiation.And in the cold season,the relationship between altitude and LST is more complicated because of climate.NDVI has little influence on LST.Climate has a significant impact on LST,and LST of the area with high precipitation is relatively high.Finally,the social and economic factors have a significant impact on the LST,the human activity and economy are more active and developed,the min of LST in the corresponding region is more high,and the social economy factors have a positive correlation with the LST.(6)The farm land and woodland have a significant regulating effect on the LST change during the day-hot.The LST of building land and water in different seasons is largely different,because of urban heat island effect,Specific heat capacity of water,reflection of water surface to solar radiation.The LST of Grassland and unused land have similar characteristics in different seasons due to their special geographical location At the same time,when the land cover changes,LST change is decided by the two relevant land cover before and after the change.LST difference of the same land cover in different geographical location difference is larger.