The effect of climate on the variation of the area of water and vegetation cover in the Sea of Najaf

Abstract

The results of the study showed that there is an effect of climatic elements on the study area, as this affected the ecosystem through the variation in the area of water cover, vegetation and land, and through the use of the water cover index (NDWI) and based on the satellite visualization (Landsat8) that the area of water cover reached its maximum area During the study period in the year 2022, it was recorded as a maximum of (158.41) square kilometers, with a percentage of (92.93%) during the spring semester on 04/22/2022, while its lowest area was recorded in the summer on 7/11/2022, as it decreased by about ( 125.85) km 2 at a rate of (73.83%), while the maximum area in which there is no water cover was about (44.61) km 2 at a rate of (26.17 %) during the summer season on 11/7/2022, while the lowest area was recorded at (12.05) km 2 at a rate of (7.07%) during the spring season on 22/04/2022, while it is clear through the use of the vegetation cover index (NDVI) that the vegetation cover area during the year 2022 recorded a maximum area of about (44.3) km 2 at a rate of (25.99%) during the summer On 7/11/2022, while the area decreased to its lowest value during the spring season on 04/22/2022, when it reached (12.8) km 2 with a rate of (7.51%). An area in the spring on 04/22/2022, when it reached (157.66) km2, with a rate of (92.49%), while it decreased to its lowest area during the summer on 7/11/2022, reaching (126.16) km2, with a rate of (74.01%). ).

The reason for this discrepancy is due to the influence of the climatic elements of the study area on the water surface of the Sea of Najaf, as with the decrease in the angle of incidence of solar radiation and the decrease in the number of hours of theoretical and actual solar brightness, the decrease in the amount of solar radiation, the decrease in wind speed, the increase in relative humidity, the increase in the amount of precipitation, and the decrease in evaporation / transpiration increases. The area of the water body to submerge the surrounding coastal lands in the Najaf Sea, as well as some island areas located within the Najaf Sea depression, which leads to a decrease in the area of lands with dense vegetation, especially during the month of March, while the area of vegetation increases with the receding of water from these lands, especially during The month of June is due to the increase in the angle of incidence of solar radiation, the number of hours of actual and theoretical solar brightness, the increase in wind speed, the decrease in relative humidity, the increase in the amount of evaporation / transpiration, and the absence of rain.