Determining the Biogeomorphic Feedback Windows Located in the Riparian Area of the Taleqan River, Iran

Riparian vegetation has a considerable effect on making the stable habitats and sustainability of the river planform. This study aimed to investigate the biogeomorphic feedback windows in Talegan river during 1991-2021.

The satellite images and aerial photographs in 1991, 2001, 2006, and 2021 was used for digitizing the vegetation area. After the geometrical correction of the images, the sub-reaches of the river were determined based on the GUS method, and the relatively stable colonies were digitized in each of the sub-reaches. Then, the traits of the BFWs were determined by field studies, including ecological process (stem density and diameter, height of vegetation and floor herbaceous), morphometric (degradation level), and biogeomorphic traits (occurrence of biogeomorphic cumulative landforms). Data were analyzed using the conceptual model and Chi-square test through SPSS 23 software.

Eighty-two BFWs were identified in the riparian area. The biogeomorphic accumulated landforms were observed in 70.7% of the BFWs. The appropriate opportunities for development of vegetation patches were observed in the upstream of the river especially in sub reaches 1 and 3. There were a lower possibility for the vegetation patches development and the stability of the river's landform in sub reaches 4 and 5. The result of Chi-square test showed a direct relationship between the establishment of biogeomorphic accumulation landforms with stem diameter, height, and density of vegetation.

There is a need to attention to the restoration of riparian ecosystems by reducing the level of human interventions and creating a favorable environment for the development of biogeomorphic feedback windows in Taleqan river. The sustainable establishment of BFWs means the sustainable establishment of vegetation habitats containing engineering vegetation, which leads to the preservation and development of the habitat as well as the stability of the river landform.