Geographical Analysis of Monthly Changes in Vegetation Cover in Shaqlawa District Using Spatial techniques

Abstract

Studying vegetation cover is crucial for many environmental applications, as it is considered one of the most important indicators of ecosystem health and an important factor in evaluating environmental changes resulting from natural and human factors. Monitoring monthly changes in vegetation cover helps understand seasonal patterns as well as the effects of climate change and land use changes.  The study aims to geographically analyze monthly changes in vegetation in Shaqlawa district during the year 2022 using NDVI and VCI indexes. The problem of the study lies in how to distribute the vegetation cover temporally and spatially during the months of the year based on the NDVI and VCI indexes and to determine the reasons for this distribution. The MODIS Terra sensor data of type MOD13Q1 were used to derive the NDVI and VCI index for all months of 2022 then analyze their temporal and spatial changes through statistical indicators. The statistical and spatial relationships of vegetation cover with climate and terrain elements were found. Multiple linear regression coefficient was used to discover the relationship between vegetation cover mass, temperature and rainfall amount, Zonal Statistics was used to find the spatial relationship between average NDVI and elevation values, and finally Clustering Analysis was used to classify the study area based on vegetation cover patterns and different elevations. The study found that the spring season is characterized by the highest average vegetation cover, reaching its peak in May (0.40), while the summer season witnesses the lowest average. As well as 43% of the area is in poor condition, 41% is in normal condition, and 15.9% is in healthy  condition. The correlation coefficient (R = 0.72) indicates a moderate correlation between temperature, rainfall and the mass of vegetation cover. In addition, the determination coefficient (R² = 0.65, R² = 0.88) shows that 65% of the changes in vegetation cover are due to temperature and 88% of the changes in vegetation cover are due to rainfall. The relationship between vegetation cover and height is negative in the winter months and early spring, while in the summer and autumn months the relationship is positive and strong.