Effect of seasonal changes of vegetation in Al Jabal Al Akhdar region on monitoring of vegetation cover and its assessing from Landsat data
Abstract
To assess and detect any changes in the vegetation cover in a region require a multi-time data to determine the changes over long period. Remote sensing technique provides the ability of monitor and discover the trends of vegetation cover change (increase or decrease), because it provides a long record for Earth observe.
Al Jabal Al Akhdar one of the areas that have experience the changes in the vegetation cover over the period of forty-five years and using the remote sensing technique was importance to assess the trends of those changes. However, despite of the availability of satellite images for the region from 1972 to the present, just some images were available for the same season.
The main aim of this research is that to determine the effect of seasonal changes of vegetation in the Jabal Al-Akhdar region on assessing the vegetation cover change by using Landsat images and vegetation index of (NDVI).
To achieve this aim, satellite images of Al Jabal Al Akhdar are used for different seasons for 1987. The seasons divided to the early growth season (spring) from April to June, the late growth season (autumn) from August to October, and inactive season (winter) from November to February.
The key finding of this research was that the vegetation cover was density in the inactive season, and then decreased in the growing season to reach to the lowest at the late growth season, which is the best period for monitoring the vegetation. That means the monitor of vegetation cover affected by soil moisture or grass that cover the ground, gave wrong values for vegetation cover, and effected on assessment of vegetation cover processing.
Therefore, the recommendation of the research is that the effect of seasonal changes of vegetation on asses need more study to investigate how to use the satellite images for different seasons for assessing of vegetation cover in any region.
