The study area is located in the northwestern part of Syria, within the administrative boundaries of Latakia and Tartous governorates, it is located between latitudes (34° 36´ 38”) and (35° 57´ 20”) N and between longitudes (35° 40´ 50”) and (36° 18´ 35”) E. (Figure 1), with a total area of about 4368 km².

The area of the Mediterranean region is characterized by moderate temperatures throughout the year. With differences in temperature, rainfall decreases as we rise from the sea, or move from west to east. The annual rainfall rate is 1000 mm, and in some areas 1800 mm, and the snow falls on the mountainous areas which are more than 1200 meters above sea level. The humidity is between 70-60% in winter and its between 70-85% in summer (Quezel, 1977) 5.

Calculating the average annual precipitation quantities reveals that the lowest recorded number was 581 mm in 2014, followed by 723 mm in 2008.

The highest figure was recorded in 2019, at 1474 mm, followed by 1391 mm in 2003 and 1276 mm in 2015 (Figure 3).

To monitor the changes occurring in the vegetation cover in terms of vitality and living mass, time series maps of EVI and LAI values for the study area were produced from the year 2000 until the year 2019 for April, which were classified within the Arc GIS software to show the distribution of values for each index. In general, these vegetation indexes are related to the vegetation cover in terms of leaf area, biomass, and percentage of land cover, which can be used as evidence of vegetative growth (Tucker, 1979; Baret and Guyot, 1991) 12, 13.

From EVI and LAI forest indexes, it was found that they record high values in these indexes. This is due to the nature of forests, which are characterized by density and layering, which gives a high biomass and a large leaf area. Forests are also known as one of the climax stages of plant communities, this is after achieving acclimatization and appropriate adaptation to resist the surrounding conditions.

The graphs of the average values of EVI and LAI for forest cover (Figure 4) show that the values of EVI in most years maintained a constant level with the exception of 2014, where the value of plant vitality index EVI decreased to 0.32, in which vitality declined slightly due to drought and the conditions of the region during the crisis that the country went through, the forests were exposed to fires and cutting as a result of military operations. As for the LAI index, it was observed that it was affected by drought in 2008 and reached 0.99, recording low values, while forests were affected positively during the years 2010, 2013, and 2015 and 2019 recording high LAI values. The highest value recorded in 2013 and 2019, which was 1.32. This due to the good amounts of rain that the region received during these years. These values corresponded to the precipitation values in terms of low and high amounts in the same years.

Figure 5, Figure 6 depict the map distribution of EVI values and LAI values, respectively, and illustrate that the majority of the locations where these index values fell were in the northwest of the forest cover. This is a result of the deterioration to which the forest cover was exposed in the north of the study area, as it was close to the armed groups that were using it in their combat operations, which exposed the forest to fires and destruction, and thus the density and vitality declined.

The other areas of the forest that were not destroyed did not show this decline during the years 2014 and 2008, despite the decrease in the index values during these years.

This form of vegetation cover in the study area is distinguished by small agricultural holdings in which fruit trees are mixed with crops in the same field. Furthermore, this cover is comparable to irrigated cover in that it receives a lot of rain due to its geographical position, which has a humid environment. This cover was very compatible with precipitation, as seen in Figure 7, which shows the average EVI and LAI values for this cover. It is noted that both indices respond and compatible in terms of high values in years with good precipitation and low values in years with bad precipitation.

We note that the highest values of the studied indices were recorded in 2019, and the values were 1.31 and 0.39 for LAI and EVI, respectively. The lowest values were recorded in the years 2004, 2008 and 2014. The values of EVI were 0.25, 0.28, and 0.26, respectively, while the values of LAI were 0.67, 0.57, and 0.64, respectively.

The distribution maps of EVI values (Figure 8) and LAI (Figure 9) show the years in which the values of these indices decreased, indicating a deterioration in the health of the cultivated cover, which are the years 2008, 2014, and 2016, where most of the studied area appears in light green, close to yellow, which indicates the lowest values of the indices, and the years in which the values were high, indicating a healthy and good condition in the cultivated cover situation, which are the years 2003 and 2015.

We can notice from the maps that the entire area is affected by a decline in plant vitality values or a decline in leaf area, which indicates that the entire cultivated cover is affected by surrounding factors, including a decline in rainfall amounts, in contrast to what we observed in the forest cover.

To determine how strong the relationship between vegetation vitality and precipitation, the correlation between EVI, LAI values and precipitation values were studied.

The study of the correlation between precipitation and vegetative indices showed a significant correlation between all vegetative indices and precipitation at the level of significance 0.01. But the correlation was strong for the planted cover where R exceeded 0.6, which indicates the great role that rain plays in the growth of this cover. But the correlation was not strong enough for forests, as the R value for EVI was 0.573 and for LAI was 0.588 (Figure 10 ). This indicates that precipitation has little effect on the vitality of the forest and that there are other factors that are more effective.