Identification of Vegetation Coverage Seasons in Iran Using Enhanced Vegetation Index (Evi)

Abstract

Vegetation coverage seasons are affected by climatic elements and changes in climatic elements influence the vegetation growth period. The purpose of this research is to identify the vegetation coverage seasons of Iran, with the help of the Enhanced Vegetation Index (EVI). In this research, 16-day data of Iran's Enhanced Vegetation Index (EVI) was downloaded from MODIS Aqua website from July 14, 2002 to March 14, 2015. Then, on the basis of nearly 10 billion cells, the long-term mean of the 16day EVI was calculated, and a time-location array was obtained at a dimension of 23*7541502. The results of cluster analysis on the Euclidean distances of this array were investigated by Ward method. This study shows that according to the local pattern of EVI in Iran, there are three different seasons, including a massive/dense season (from the April 14 th to the June 1 st ) that the highest density is in the north and west of Iran, a transition season (from the June 17 th to the October 7 th ) that the highest compression on the Caspian Sea coast, and less severity along the Alborz heights, and the season of thinning (from the October 23 rd to the March 29 th ), the highest density of which is along the coast of the Caspian Sea, on the Khuzestan plain, and also in the southern half of the country.

Vegetation of the southern part of the Caspian Coast and its nutritional value

“…Based on the analysis of almost 10 billion cells for 2002-2015, 16-days EVI was calculated. The study revealed territorial and seasonal differences in plant communities in the Khuzestan plains, and also in the southern part of Iran (Sobhani et al, 2018).…”

“…They determined that the distribution of four ecological groups of plants in the studied territory is mostly related to type of soil, clay content in soil, total nitrogen, organic substances, phosphorus and exchangeable bases; lower effects on the vegetation composition were exerted by height above sea level, surface angle, percentages of sand and silt, C/N ratio and pH (Rad & Shafiei, 2010). Sobhani et al (2018) studied the seasonal changes in the vegetative cover of Iran using Enhanced Vegetation Index (EVI). Based on the analysis of almost 10 billion cells for 2002-2015, 16-days EVI was calculated.…”

Seasonal and Long-Term Changes of Vegetation Index of Arable Lands of Bryansk Region (Central Russia): Regularities and Dynamics Factors

“…The "specialization" of satellite images as a source of information is associated with wide possibilities for analyzing the state and dynamics of agrocenoses of large regions with an area of tens of thousands of square kilometers, with a distraction from local variability of vegetation factors. The experience of satellite filming for sustainable agriculture in Central Russia is relatively small, but at the same time, it is interesting for the wide variety of edaphic conditions and the instability of weather conditions both within the growing season and in a number of years (Biewer et al, 2009;Grzegozewski et al, 2017;Sarmah et al, 2018;Sobhani et al, 2018).…”