Estimating land surface temperature of land use and land cover in Dena county using single window algorithm and landsat 8 satellite data

Land Surface Temperature (LST), a significant variable of micro climate and radiation transfer within the atmosphere, is one of the most important criteria in zonal and regional planning because it is a major factor in controlling the Earth’s biological, chemical and physical processes. Natural and man-made activities, especially land use and land cover, by changing the physical and biological conditions of a region are an important parameter in the amount of land surface temperature.
Material and In this study, the relationship between land surface temperature and vegetation cover associated with land use and the land cover patterns of Dena County in 2016 were investigated using a Single Window algorithm and Landsat-8 data. The split-window algorithm is a dynamic mathematical tool which estimates land surface temperature (LST) using ground information, brightness temperature of thermal bands of the TIRS sensor, the land surface emissivity (LSE) factor and fractional vegetation cover (FVC) obtained from a multiband OLI sensor.
Based on classification of images of the Landsat-8OLI sensor in 2016 with an accuracy of about 80% and the kappa coefficient 0.90, rangeland and residential areas with 50.67 and 0.3 percent, respectively, were allocated the highest and the lowest areas of Dena county. The mean of land surface temperature in Dena County is about 32 ° C and the mean of the land cover index is about 0.14. In analyzing the relationship between LST and the vegetation index (NDVI) in Dena County and in each category of land use and land cover, results showed a different trend so that there is a positive and significant relationship between NDVI and LST in the whole of Dena County and rangeland in the event that there is no significant relationship in other land uses such as forest, farm and garden and residential area.
Various factors affect the type and shape of the relationship between NDVI and LST such as land use and land cover, vegetation cover, season, time of day, type of ecosystem, latitude and factors in triggering the growth of vegetation such as water and solar energy. The main cause of the ineffectiveness of vegetation cover in reducing the land surface temperature of Dena County is the lack of a sufficient amount of vegetation cover. However, the determining factor of temperature in Dena County is not increases or decreases in vegetative cover but is rather a change in the height above sea level. In other words, the effect of altitude on temperature is more important than the effects of vegetation on the Earth's surface temperature. At the lower altitude of Dena County where the temperature is relatively high and there is enough vegetation to grow, the vegetation cover is denser and more abundant and therefore there is a positive relationship between land surface temperature (LST) and vegetation cover index (NDVI).