Temporal analysis of net radiation in the metropolitan area of San Luis Potosí - México using landsat 5 and 8 satellite images

The San Luis Potosí Valley is a basin situated in the municipalities of San Luis Potosí and Soledad de Graciano Sánchez belonging to the San Luis Potosí State and which make up the metropolitan area. This state is located in the north-central zone of México; it has a territorial extension of 64,165 m2 that represents 3.12 of the national territory. It is bounded to the north by the states of Coahuila, Nuevo Leon and Tamaulipas; to the south by Guanajuato, Queretaro and Hidalgo; to the east by Veracruz and to the west by Zacatecas and Jalisco. The analysis of the radiation capture phenomenon was carried out in the San Luis Potosí Metropolitan Area (ZMSLP). The study area is located between latitudes 22 20′ 00″ and 22 02′ 00″ north and longitudes 101 12′ 00″ and 100 44′ 00″ west. Net radiation is the phenomenon in which radiation fluxes interact between atmosphere and the earth's surface. This phenomenon leads to processes such as evapotranspiration and photosynthesis. The net radiation analysis can be performed by three methods: (a) by using radiation monitoring stations, (b) by statistical models using data from meteorological stations such as temperature and relative humidity, and (c) by using satellite imagery. Since satellite images offer the possibility of analyzing large tracts of land, this method has been chosen to carry out the study using two images per year, one for the dry season and one for the rainy season between 1990 and 2017. The results show a considerable reduction in net radiation between the study periods, possibly due to the metropolitan area growth that impacts on the environment and therefore to the processes mentioned above.