Monitoring the impact of climate changes on the Natural Difference Water Index (NDWI) in the Hawizeh Marshes

Keywords: climate change, NDWI index, Hawizeh Marsh, Mann-Kendall coefficient

Abstract

Assessing drought risks is important due to their social and economic impacts on water resources, agriculture and ecosystems. In this study, the effects of climate change on the change in water area were monitored and evaluated in the Al-Hawizeh Marshes in southeastern Iraq, specifically within the area of Maysan Governorate. For this purpose, the trend in rainfall change was evaluated according to the Man-Kendall coefficient, in addition to determining the natural water variation index (NDWI), for specific years, including 2000, 2005, 2010, 2015, 2020, and 2023, with the aim of comparing the results of the index with the amount of rain falling on the Hawiza marsh basin. How much did it become clear, by extracting the values for the NDWI, that the year 2000 was one of the most water-abundant years, as the value of the index reached 0.6, following this year, the year 2005, when the index also recorded high values, amounting to about 0.4, and it is clear that there is a gradient in the water area covered by the Hawizeh Marshes. From the year 2000-2023, as we also see that in 2010 the area of the natural water variation index during this year reached about 0.3. We conclude from what was stated through the analysis that the water area in the Hawizeh Marshes decreases with the progression of the years, as the year 2023 recorded the lowest value of the index amounting to 0.2. Which confirms the impact of the negative trend of rainfall on the main and nourishing sources of the Hawizeh marshes, such as the Karkha, Tayeb, and Duwayrig rivers, as well as the Musharrah and Al-Kahla rivers.