Long-term evaluation of the population change trend of different plant species in lagoons is of great importance in preserving the environment. Lagoons are the fundamental habitats for aquatic biodiversity conservation, which has at least one relatively narrow connection to the sea. In this research, Landsat time-series data are used to investigate the changes in Azolla (or green devil) expansion, and its effective factors over 30 years from the arrival of this aquatic fern from 1988 to 2018 in the International Lagoon of Anzali in the North of Iran using the spectral angular mapper (SAM) method and related field data. The results indicated that (1) the changes of Azolla plant expansion have a direct correlation with the volume of lagoon water and rainfall and an inverse relation with the region temperature, (2) The spread of Azolla has not been steady over three decades, increasing in some years and decreasing in others, (3) The high Azolla surface cover has caused environmental hazards in the lagoon and has reduced the value in the eastern, southwestern, and partly central parts of the area. Therefore, in order to maintain balance in the natural ecosystem of Anzali Lagoon, fundamental decisions must be made for determining the range and shelter of the lagoon and controlling the outflow of water resources.

长期评估泻湖中不同植物物种的种群变化趋势对保护环境具有重要意义。泻湖是水生生物多样性保护的基本栖息地，与海洋至少有一个相对狭窄的联系。在这项研究中，Landsat时间序列数据用于调查Azolla（或绿色魔鬼）扩张的变化及其影响因素，从1988年到2018年，这种水生蕨类植物进入国际礁在伊朗北部，使用光谱角度映射器（SAM）方法和相关的现场数据。结果表明：（1）满江红植物扩张的变化与泻湖水量和降水量成正比，与区域温度成反比，（2）满江红的扩散在过去的30年中一直没有稳定，在某些年份中有所增加，而在另一些年份则有所下降。（3）高的满江红表面覆盖率对泻湖造成了环境危害，并降低了东部，西南部，以及该区域的中部地区。因此，为了在安扎里泻湖的自然生态系统中保持平衡，必须做出基本决定，以确定泻湖的范围和庇护所，并控制水资源的流出。