| The differences in the thermodynamic properties of LUCC have always been considered as the root cause of the land surface temperature.Therefore,as the LUCC,the land surface temperature also changes,which in turn affects the surface thermal environment.Therefore,understanding the impact of LUCC on the surface thermal environment is very important to assess the thermal effect configuration of land landscape planning.In this study,the Landsat remote sensing images of the 6th period of Haitan Island 2000-2013were selected.First,the random forest classification method was used to extract the land cover information in different periods of the area,and the land cover results were analyzed;second,the Jiménez-Mu oz single The channel algorithm inverts the surface temperature and analyzes the results.Finally,the land cover information and surface temperature information are superimposed and analyzed,and the land is quantitatively analyzed by introducing surface characteristic parameters,temperature contribution ratio,distribution index,center of gravity transfer trajectory,etc.The intrinsic relationship between coverage and its changes and surface temperature.The specific conclusions are as follows:(1)2000-2013,the construction land of Haitan Island increased by 34.18km~2,the forest land increased by 2.90km~2,the water area decreased by 23.14km~2,and the cultivated land decreased by32.76km~2.The increased construction land is mainly distributed in the southwest of Haitan Island and near the town of Tantan where the county seat is located.The increase in construction land in Haitan Island in 2010-2013(after the establishment of Pingtan Comprehensive Experimental Area)was 2.32times that in 2000-2010(before the establishment of Pingtan Comprehensive Experimental Area),and the decrease in water area was 2.44 times that before the establishment.The reduction of cultivated land is 3.05 times before the establishment.(2)The classification results of tidal flats and waters in the same year in different seasons will be very different,indicating that the distribution of tidal flats in the study area has obvious seasonal differences.In 2000-2010 and 2010-2013,the annual change rate of the single land cover type on the construction land of Haitan Island increased from 4.35%to 23.48%.The dynamic degree of the comprehensive land cover change of Haitan Island is 3.35 from 2010 to 2013.The construction land in each period from 2000 to 2013 is represented as transfer-in,and is spatially expressed as the development of southwestern Haitan Island.(3)Based on the normalization of the surface temperature,the natural breakpoint method is used to classify the temperature,which is divided into 7 levels,namely:extremely low temperature area,low temperature area,lower temperature area,middle temperature area,higher temperature Zone,high temperature zone and extremely high temperature zone.The area statistics of the temperature zones at different levels of the 6th phase of the Haitan Island 2000-2013 image were analyzed,and the temperature areas of each phase of the image were roughly normally distributed.It can be seen from the statistical results that the surface temperature of bare land,construction land and sandy land is higher in summer,and the surface temperature of bare land,construction land and cultivated land is higher in winter.Among them,the temperature standard deviation of each category in summer is the largest,indicating that the surface temperature difference of each category in summer is large,and the temperature standard deviation of each category in winter is the smallest,indicating that the surface temperature difference of each category in winter is not large.(4)Exploring the relationship between surface feature parameters and surface temperature,it is concluded that when NDVI is greater than 0,NDVI is negatively correlated with surface temperature.Among them,the significance in winter is worse than that in summer,which may be due to the difference in surface temperature in summer being greater than that in winter.When NDVI decreases by 10%,the average surface temperature in winter increases by 1.29K,and the average surface temperature in summer increases by 2.06K.Among them,when MNDWI is less than 0,NDVI and surface temperature are positively correlated.When MNDWI is greater than 0,the surface temperature increases with the value of MNDWI However,the seasonal effect is not significant;NDBI is positively correlated with surface temperature,that is,the larger the NDBI value,the higher the surface temperature.For every 10%increase in NDBI,the average surface temperature in winter increases by 1.71K,and the average surface temperature in summer increases by 1.87K.(5)The transfer of cultivated land in summer shows a warming effect on the surface temperature,and the transfer of cultivated land in winter shows a cooling effect on the surface temperature;the transfer of water in summer and winter shows a warming effect on the surface temperature;the water area in each season After conversion to construction land,the surface temperature shows a large increase,and the temperature contribution to the construction land is positive and largest,and it is the most obvious in summer.The forest land has the same characteristics after conversion to construction land.In general,the conversion of waters to construction land has a warming effect on the surface temperature in any season.(6)By calculating the distribution index,it can be seen that the construction land and cultivated land in the study area act as a heat source to the thermal environment in multiple periods.In addition,the summer heat source area is mainly distributed in the construction area dense area of the study area(tancheng town and southwest of the study area);the winter heat source area is more evenly distributed;during 2000-2013,the center of gravity of the heat source area shifts in different seasons.The center of gravity of the land and cultivated land is in the same direction of migration;comparing the contribution of the conversion of different land types to construction land and the unchanged construction land to the construction land heat source area,the construction land heat source area in the research area is a continuous accumulation process.The continuous extension of the span,in which the impact of construction land unchanged on the construction land heat source area continues to decrease,and the impact of the conversion of various types of construction land on construction land heat source area continues to increase.From this,understanding the impact of different land conversions on the construction land heat source area can provide theoretical support for further urban development and construction. |
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