## 3 Results
### Vegetation Indices
#### 3.1.2 Mean Annual VIs  
The mean annual NDVI, EVI, and SAVI from 2000 to 2019 indicated identical spatial trends for different landscape situations described above, but differed in spatial vigor (Figure 4). All VIs represented a regional trend of strong VIs for the northwest and southeast of the study area and small values for the industrial and suburban areas. Maximum annual VI trend was observed in the eastern, central, and southeastern parts of the study area. The spatial variability of annual mean VIs was consistent with regional climate conditions in northern and southern Punjab (Figure 4). With greater rainfall in northern parts, an increasing trend in vegetation (trees, grasslands, and farm ground) forms longer growing seasons. Figure 5 displays the mean annual variation in the VIs for the period from 2000 to 2019. It shows spatial variations of annual mean VIs from one year to the next, which can be used for monitoring purposes. In comparison, in southern Punjab, relatively small growing seasons are starting in the desert area. In this region, vegetation growth is limited throughout the year by low precipitation. The NDVI image displays higher values in most instances than the images in the EVI and SAVI time series. In the northern part of Punjab, dense coniferous forests are found in high mountains with large annual precipitation. Grasslands have spread almost throughout the entire Punjab; NDVI displayed higher mean annual values than EVI and SAVI time-series images. To highlight the spatial variations in distinctive eco-regions between the NDVI, EVI, and SAVI, three large transects were used as samples within the mean VIs time-series images of the year (Figure 4). All transects start with sparse vegetation and cross heavily vegetated areas to cover a wide variety of VI values, except transect c. All these transects include forests, croplands, grasslands, savanna, and barren land. Similar patterns can be found between the VI profiles (Figure 5). Nevertheless, the NDVI profiles observed wider data ranges than the EVI and SAVI profiles. Figure 4: Spatial annual average distribution NDVI, EVI, and SAVI were obtained from 16-day MODIS data from 2000 to 2019 in Punjab. Transect a starts from the northwestern forest area near Attack and ends in the east-southeast cropland areas and is about 400 miles long. Mostly barren land, cropland, and grassland are found in this transect region. The transect extends to cropland, sparse grassland, and crosses the barren area in the district of Chakwal, showing very low VI values. Transect b starts from sparse grassland and cropland areas in the central Punjab, crosses a mix of forest, sparse vegetation, and agricultural area in central Punjab, and ends in the east-southeast cropland areas. Figure 5: Annual mean VI profiles for the period 2000 to 2019. (**a**) Gradient eco-region that passes several oases; (**b**) gradient elevation; (**c**) variation along latitude 34\({}^{\circ}\) N. B, C, F, and G stand for barrenland, cropland, forest, and grassland, respectively. See Figure 4 for the locations of the three transects. in the cropland areas. NDVI and SAVI display high VI values compared to EVI values in this area. Transect c follows the north to south latitude line from 34\({}^{\circ}\) N to 29\({}^{\circ}\) N and is about 800 km long. A small part of grassland and highly evergreen needle leaf forest characterize the northern part of the transect, where SAVI and NDVI showed high variation, whereas EVI had little variation. The VI values were higher between 33\({}^{\circ}\) N and 34\({}^{\circ}\) N and showed a rather smooth behavior. This area was also categorized as homogeneous, mainly forest, cropland, and grassland cover. The higher values of VIs were found in northwestern Punjab between 33\({}^{\circ}\) N and 34\({}^{\circ}\) N latitudes, parallel to the agricultural areas, forests, and steppe along the mountains. The VIs values were lower in the zone between 33\({}^{\circ}\) N and 32\({}^{\circ}\) N due to barren land and shrublands.