Project of land surface temperature maps for selected districts of Gdynia in different seasons
The aim of the project was to find the relationship between land use and land surface temperature for selected districts of the city of Gdynia.
In the modern world, urban areas are among the fastest growing areas and the most transformed parts of the Earth's surface. Cities occupy an increasingly larger area, which causes a dynamic increase in the value of the built-up areas within their borders. In the context of climate change, green areas like parks and urban forests are becoming an important factor influencing the land surface temperature and, consequently, the local change in air temperature.
As part of the project, I developed land surface temperature maps for all seasons in 2021/2022. I also examined the condition of vegetation in March 2022, calculating the vegetation index. Additionally, I made a map of the city of Gdynia and the studied districts of Gdynia, which enable the identification of the type of land cover.
Satellite images from the Landsat 8 mission were used to prepare maps of land surface temperature and vegetation condition. The mathematical and visual development of the project was made in ArcGIS Pro. Satellite scenes from the Sentinel 2 mission were used to develop a map of Gdynia and its studied districts.
In the modern world, urban areas are among the fastest growing areas and the most transformed parts of the Earth's surface. Cities occupy an increasingly larger area, which causes a dynamic increase in the value of the built-up areas within their borders. In the context of climate change, green areas like parks and urban forests are becoming an important factor influencing the land surface temperature and, consequently, the local change in air temperature.
As part of the project, I developed land surface temperature maps for all seasons in 2021/2022. I also examined the condition of vegetation in March 2022, calculating the vegetation index. Additionally, I made a map of the city of Gdynia and the studied districts of Gdynia, which enable the identification of the type of land cover.
Satellite images from the Landsat 8 mission were used to prepare maps of land surface temperature and vegetation condition. The mathematical and visual development of the project was made in ArcGIS Pro. Satellite scenes from the Sentinel 2 mission were used to develop a map of Gdynia and its studied districts.
Map of the city of Gdynia and the analyzed districts of Gdynia
The condition of vegetation in selected districts of Gdynia calculated on the basis of the NDVI index
The NDVI (Normalized Difference Vegetation Index) was calculated, in which the highest index is achieved by healthy, lush vegetation (from 0.5 to 1). Low vegetation and vegetation in the initial stage of development ranges from 0.2 to 0.4, while the lowest rate is recorded in areas with exposed soil or built-up areas (from -0.1 to 0.2) and flooded areas (close to -1)
Land Surface Temperature maps
I made land surface temperature maps for all seasons, starting from autumn (October 30, 2021), late winter (March 14, 2022), spring (May 17, 2022) and ending with summer (August 14, 2022). After performing the necessary calculations on the rasters to calculate the land surface temperature, I cropped the image to the analyzed administrative boundaries of the study area and applied layers of buildings and roads. I extracted the above data from the Topographic Objects Database, which was available on the geoportal map portal.
The lowest surface temperature is found in areas densely covered with tall vegetation, mainly represented by forests, which cause more shading. Lower values are observed for areas covered with low greenery, found near tall trees. In contrast, grassy areas near buildings or exposed soils show much higher surface temperatures.
The highest possible surface temperatures definitely prevail in areas characterized by exposed soil. For every season analyzed, the highest surface temperatures appeared in these areas, despite lower air temperatures. Soils that take on a darker color can absorb heat faster and accumulate it longer. Heat absorption is made possible by high sunlight and the scant presence of green areas near the soils.
The analysis showed that wooded areas show significant mitigation measures and lower the temperature surface area in relation to wasteland or fields. Areas developed independently intensities have a much lower surface temperature when located in vicinity of forests.
