Climate change has worsened and has widespread impact. This is partly due to the release of greenhouse gases from human activities, which cause the greenhouse effect. This leads to the global temperature rising to an unusual level, otherwise known as global warming. This study aimed to use a split-window algorithm to retrieve the land surface temperature via Landsat-8 OLI/ TIRS data in the Roi Et province area. The research methodology included 1) separating the Landsat-8 OLI data into four types of land use, i.e. the agricultural, forest, urban and water areas and 2) the data for Landsat-8 OLI bands 4 and 5 and Landsat-8 TIRS (bands 10, 11) being analysed to retrieve the land surface temperature using a split-window algorithm. The results from the land-use separation showed that the total area of Roi Et was 8,299.46 km 2 divided into a 4,787 km 2 agricultural area, which accounted for 60.81%; a 1,555 km 2 forest area, accounting for 19.75%; a 1,212 km 2 urban area, accounting for 15.39% and a 317.44 km 2 water area, accounting for 4.03%. The land surface temperature analysis result using a split-window algorithm indicated that the average temperature of Roi Et was 34.74°C. Moreover, it was found that the land surface temperature of the urban area had the highest mean land surface temperature, followed by the forest area, the agricultural area and the water source area, respectively.

Availability of solar energy is crucial for most technological solar applications. The objective of this study is to predict monthly average and global solar radiation patterns on Maha Sarakham horizontal surface of Thailand. Two correlation equations have been successfully developed, one from Angstrom model and the other from Liu-Jordan model, with the minimum and maximum clearness index 0.45 and 0.65 for the equation derived from Angstrom model and 0.30 and 0.95 for the equation derived from Liu-Jordan model. Data of sunshine hours as well as global and diffuse solar radiation was collected at the location and was predicted using equations developed from corresponding models. After validation procedure was conducted, the empirical data was then compared to predicted data. It can be concluded that the developed equations can be used to estimate the diffuse and global solar radiation and also indicate the solar energy availability at Maha Sarakham of Thailand with satisfactory level. This obtained knowledge and information can be applied to other locations with the same geographical conditions as well as used in further researches. Streszczenie. Celem artykułu jest prognozowanie przeciętnych miesięcznych i globalnych możliwości systemu solarnego w Tajlandii w miejscowości Maha Sarakham. Opracowano równania korelacyjne bazujące na modelach Angstroma i Liu-Jordana z indeksem przejrzystości powietrza 0.45-0.65 (Angstrom) i 0.30-0.95 (Liu-Jordan). Otrzymane równania pozwalają na prognozowanie wydajno sci systemów słonecznych także w innych geograficznych warunkach. Analiza i prognozowanie możliwości systemu solarnego w Maha Sarakham w Tajlandii