The Effect of Vegetation Cover on Air Temperature Data for Weather Stations Intended for Agricultural Purposes

Abstract

According to what is stated in the scientific literature, vegetation cover affects air temperatures in the areas in which it is found and works to reduce them through the processes of evaporation and transpiration, whether from the plant itself or wet surfaces within a specific area. Knowing the exact extent of the effect helps in choosing the most appropriate places to install stations for agricultural monitoring to be truly representative of the agricultural reality, and also helps in knowing the most appropriate safety for planting vegetation within cities. We chose two stations that were installed for agricultural purposes in agricultural areas within the city of Baghdad: Abu Ghraib station (A) in Abu Ghraib district and Al-Rashidiya station (B) in Rashidiya district. The monthly average air temperature for stations A and B was obtained from the Agricultural Meteorological Center of the Ministry of Agriculture for a period of 5 years (2018–2022). The results of this research showed, in general, that station (A) recorded values very close to (B), and in some periods, (B) recorded values higher than (A), and it was not recorded that (A) was higher except in a few months., and statistical analysis of the data shows that the highest difference between them was (1.48) in May 2018, and the lowest difference between them was (0.01). In September 2022, to study the effect of vegetation on temperature, the Natural Difference Vegetation Index (NDVI) was created and NDVI circular maps were made around each station, the first case with a radius of 10/km with an area of (315)/km2 and the second case with a radius of 2/km. With an area of (12.56)/km2. In both areas, no clear effect of vegetation on the temperatures recorded by the two stations was observed, despite the abundance of plants, water bodies, and barren lands surrounding the station. It was found that the most noticeable effect was the vegetation cover closest to the station at a distance ranging from 150 to 200 meters, and this was clearly shown in (A).