Investigating the trends of Anzali wetland connected domain coverage using remote sensing techniques and DPSIR conceptual framework

Over the past few decades, human activity had a significant impact on coastal wetlands around the world. Anzali is one of the 18 Iranian wetlands of international importance listed in Ramsar Convention. This unique ecosystemin the world with high ecological diversity is highly threatened by various factors such as pollutants, sedimentation, unauthorized development of urban infrastructure, over-harvesting of wetland resources, land use changes, and invasive species. In this study, we analyze structural and functional changes in the Anzali coastal wetland from 1994 to 2018, using the "drive-pressures-status-effects-responses-(DPSIR)" model and data collected from the Anzali Coastal Wetland.

Landsat 5 and 8 TM and OLI sensors for 1994, 2008 and 2018 were used. The land cover maps for these years were prepared in 5 categories of water body, wetland, wetland plants, pasture and agricultural land using the supervised classification with maximum likelihood algorithm in ENVI5.3 software. Changes were identified to assess the current status of the wetland and then the conceptual framework of DPSIR was used to determine the relationship between human activities and environmental activities and to describe environmental problems.

According to the results of the first period (1994-2008), the water body had the highest area change with 7.63% decrease, which was the most influential part of the wetland plants class, with 1045/98 hectares of water body converted into wetland. The wetland plants was second with 3.84 percent. During the second period (2008-2018), the water body had the most change in this period, with a decrease of 14.19%, as in the previous period. Over the entire study period from 1994 to 2018, the water body increased from 4749 hectares in 1994 to 1042 hectares in 2018, the largest conversion to wetland plants. The area of wetland, wetland, pasture and agricultural land uses increased by 10.92%, 0.78%, 4.48% and 5.66%, respectively. The results of maps accuracy assessment show that overall accuracy for year 2018, 96.31, year 2008, 94.14 and for 1994, 90.29% and kappa coefficient were 0.94, 0.92 and 0.87, respectively. Is. Also the driving forces in this research are population growth, industry and tourism.

The process of change in the Anzali Wetland is first in a natural sequence and then of human origin. So that the area of the water reservoir is reduced and added to the cover of wetland plants and wetlands and eventually to agricultural lands and the fertilizers and pesticides used in agriculture along with domestic wastewater, industrialization through rivers into the Anzali Wetland. It enters the wetland feed, thereby accelerating the process of wetland destruction. Protecting this wetland requires people's participation, education and culture at the grassroots level.