Mapping of diatom indices by remote sensing to evaluate the Um El-Naaj Marshes water quality

This study was conducted to evaluate the water quality of the Um El-Naaj Marshes using the community of diatoms bioindicator and mapping them by remote sensing data. From November 2018 to April 2019, epiphytic diatoms were collected from host aquatic plants of Zannichllia palustnia from six sites in the Um El-Naaj Marshes. According to the results, the Diatom Index (DI) ranged from 3.5 in autumn 2018 to 2.4 in summer 2019, i.e in sites 3 and 2, respectively. The index of trophic diatoms (TDI) for the majority of study sites showed the mesotrophic state ranged from 47.5 to 62.5 in all seasons. Except for site 2, which had the lowest value (35) in the summer of 2019, and station 3 which had a greater value than 60 in the Autumn of 2018 and spring of 2019, other sites had oligo-mesotrophic states. The general diatomic index (GDI) values showed the lowest value (9.6) at site 2 in the summer of 2019 and the greatest value (14.4) at site 3 in the spring of 2019. In addition, in the current study, maps were produced using remote sensing methods to visualize the values close to the studied sites to show the quality state of the whole marsh.