The land surface temperature of Yola (latitude 9°11'N to 9°20'N and longitude 12°23'E to 12°33'E) North-eastern Nigeria was estimated using landsat-7 ETM+ satellite images. ...The land surface temperature of Yola (latitude 9°11'N to 9°20'N and longitude 12°23'E to 12°33'E) North-eastern Nigeria was estimated using landsat-7 ETM+ satellite images. ENVI 4.5 software, and Thermal band 6.2 were used for the estimation, land surface temperature, from Landsat-7 ETM+ imagery sensors acquired as a digital number (DN) range from 0 - 255 in thermal band. DNs were first converted to radiance values in Wm-2·sr-1·μm-1, using the bias and gain values specific to an individual pixel, then the radiance was converted eventually to surface temperature (in Kelvin). The results indicate that there is a significant variation in land surface temperature between the two different seasons in Yola. The mean surface temperatures estimated are 307.9 K and 298.1 K during the dry and rainy seasons respectively. The result obtained was compared with data obtained from Meteorological Department. The estimated land surface temperature showed a good correlation, with a difference of 2 K to 3 K.展开更多
Last couple of decades witnessed a rapid escalation in urban temperature of Peshawar city and its neighboring localities. This alarming condition gave birth to climatic term Urban Heat Island (UHI) created drastic alt...Last couple of decades witnessed a rapid escalation in urban temperature of Peshawar city and its neighboring localities. This alarming condition gave birth to climatic term Urban Heat Island (UHI) created drastic alteration in surface temperatures. In this study, thermal infrared remote sensing data has been employed to map out and monitor such micro-climatic variation in temperatures in land use/land cover exposed surface to the environment. To assess these outcomes resulting from human activities, Landsat TM data band 6 was subjected through ERDAS Imagine 2013. For further processing, ARC GIS helped a lot in making maps to pinpoint the heat island in and around the city. Moreover, a relationship of land surface temperature with urban sprawl, environmental and industrialization was established. This study has shown a substantial upsurge in temperature about 1 to 3 degrees. Urban sprawl and industrialization at the edges are accounting for these conditions. Urban and industrial data has also reinforced the fact being drawn from remotely sensed data. Hence, evaluation of Land surface temperature data captured through remote satellite has proven to be effective tool not only for monitoring and analyzing temperature but also for assessing its adverse impacts on the environment and climate.展开更多
文摘The land surface temperature of Yola (latitude 9°11'N to 9°20'N and longitude 12°23'E to 12°33'E) North-eastern Nigeria was estimated using landsat-7 ETM+ satellite images. ENVI 4.5 software, and Thermal band 6.2 were used for the estimation, land surface temperature, from Landsat-7 ETM+ imagery sensors acquired as a digital number (DN) range from 0 - 255 in thermal band. DNs were first converted to radiance values in Wm-2·sr-1·μm-1, using the bias and gain values specific to an individual pixel, then the radiance was converted eventually to surface temperature (in Kelvin). The results indicate that there is a significant variation in land surface temperature between the two different seasons in Yola. The mean surface temperatures estimated are 307.9 K and 298.1 K during the dry and rainy seasons respectively. The result obtained was compared with data obtained from Meteorological Department. The estimated land surface temperature showed a good correlation, with a difference of 2 K to 3 K.
文摘Last couple of decades witnessed a rapid escalation in urban temperature of Peshawar city and its neighboring localities. This alarming condition gave birth to climatic term Urban Heat Island (UHI) created drastic alteration in surface temperatures. In this study, thermal infrared remote sensing data has been employed to map out and monitor such micro-climatic variation in temperatures in land use/land cover exposed surface to the environment. To assess these outcomes resulting from human activities, Landsat TM data band 6 was subjected through ERDAS Imagine 2013. For further processing, ARC GIS helped a lot in making maps to pinpoint the heat island in and around the city. Moreover, a relationship of land surface temperature with urban sprawl, environmental and industrialization was established. This study has shown a substantial upsurge in temperature about 1 to 3 degrees. Urban sprawl and industrialization at the edges are accounting for these conditions. Urban and industrial data has also reinforced the fact being drawn from remotely sensed data. Hence, evaluation of Land surface temperature data captured through remote satellite has proven to be effective tool not only for monitoring and analyzing temperature but also for assessing its adverse impacts on the environment and climate.
