Feasibility Study of Ecological Corridor Design in Tabriz Metropolitan: A case study of Dokamal Street Route

ABSTRACT
Today, the development of cities without considering ecological processes has led to the destruction of communities and ecological processes and the reduction of environmental quality, which ecological design provides the possibility of restoring and improving the ecological functions of the urban landscape. Focusing on identifying and strengthening ecological paths can lead to the growth and promotion of diverse ecosystem services. Therefore, the aim of this research is to design an ecological corridor along Dokamal Street in Tabriz metropolitan. In this study, GIS and Envi, Fragstats and TerrSet software were used to analyze the data. In this study, the landscape of Tabriz city was first evaluated over the past three decades and land use maps were prepared for the years (2003 and 2023) to compare them and examine the trend of changes. This trend was also examined in more detail by quantifying landscape metrics using the Fragstats software. The results showed that based on the Attrition index, 30.55 hectares of land, 89.75 hectares in the Creation index, and 15.74 hectares in the Dissection index, have experienced changes that indicate landscape fragmentation. The results also showed that, based on the Cohesion Index, built-up areas have the highest cohesion among the land cover within the Dokamal Street area. Considering the availability of wasteland around Dokamal Street, a feasibility study was conducted using TerrSet's Corridor Planning software to design a 3.6 km long, circular ecological path with an area of 8 hectares, which, if implemented, could partially compensate for this disruption.
Extended Abstract
Introduction
 Today, the development of cities without considering ecological processes has led to the destruction of ecological processes and a decrease in the quality of life in the urban environment. Ecological design provides the possibility of restoring and improving the ecological functions of the urban landscape. Urban green corridors are essential both as a chain that connects urban green areas and as arteries to strengthen and maintain urban ecosystem services. Focusing on identifying and strengthening these routes can lead to the growth and promotion of diverse ecosystem services. Reducing urban heat islands, cleaning the air and absorbing and sequestering carbon, reducing the risk of urban flooding, and reducing noise pollution are the major benefits of strengthening these green corridors. Ecological corridors are designed to increase human exchanges between habitats, promote genetic exchanges, and reduce population circulation. Therefore, the purpose of this research is to design an ecological corridor along Dokamal Street in Tabriz metropolitan
 
Methodology
 The present research is descriptive-analytical in terms of method and has a developmental-applied nature. The required information was collected using library, documentary, electronic resources, surveys and field observations. During the different stages of the research, various software such as Fragstats, TerrSeet, ArcGIS, Envi, Google Earth were used. In this research, Fragstats 4.2 software was used to measure landscape metrics and analyze urban landscape continuity, Google Earth Professional software was used to correct existing land use boundaries, collection obstacles, and update existing changes and maps, and to display obstacles in real time on the landscape, ENVI 5.3 software was used to combine bands, process and classify satellite images, and ArcGIS 10.5 was used to prepare maps and analyze data from other software.
Also, in this research, supervised classification and maximum likelihood algorithm were used to classify the lands, and connectivity indices were also used to evaluate the continuity of the landscape, and finally, the Corridor Planning model was used to determine the optimal corridors. In general, the following steps were taken in this research:
1-Collecting resources, library and field studies
2-Obtaining satellite images for the target area during two time periods (2003-2023)
3-Performing pre-processing operations, classifying the images, and finally preparing land use maps
4-Performing post-processing operations and assessing the accuracy of the classification and analyzing the changes that occurred
5- Selecting landscape metrics to quantify and calculate the desired metrics
6-Detecting and analyzing changes using the calculated metrics
7-Analyzing and evaluating the continuity of the landscape of Dokamal Street in the current state
8-Drawing optimal minimum cost round-trip routes to improve the continuity of Dokamal Street based on the concepts of graph and minimum cost
 
Results and discussion
The findings showed that in the CA and PLAND (land use area and percentage) indices, built-up patches have increased during these two decades, from 45 hectares in 2003 to 88 hectares in 2023, while the rest of the land uses have also decreased. In the NP (number of patches) index, the built-up land classes, green space, and river have experienced an increase in the number of patches between 2003 and 2023, indicating that the existing patches have become fragmented over time and have lost their coherence and integrity. In the ED (patches edge density) index, built-up land uses, green space, and rivers have significantly lost their continuity and become more granular in the case of Do Kamal Street in Tabriz. The increase in urbanization and the growth of more than 94% of the area of built-up areas over the past 20 years have caused the destruction of ecological spaces and, as a result, the fragmentation of green lands and are considered the main factor in the fragmentation of the urban landscape of Dokamal Street in Tabriz. In this measure, built-up land, agriculture, gardens, and green spaces have changed the most and have become more discrete and fine-grained than in previous periods. In the LSI (edge density) measure, the shape of the landscape has had an increasing trend, and overall, this increase indicates that the shape of the landscape of Dokamal Street, Tabriz, has moved towards becoming more complex and geometrically irregular in terms of green lands. In the LPI index, the use of barren lands and green spaces has decreased, but the use of built-up lands and rivers has increased due to the construction of continuous and integrated lands. Qualitative analysis of changes during the period 2003-2023 showed that changes of Attrition, Creation and Dissection occurred. Mainly barren land uses and green spaces have undergone Attrition (i.e. the number and area of patches have decreased). Built-up land uses have mainly undergone Creation (i.e. the number and area of patches have increased). Green space land uses have mainly undergone Dissection (i.e. the number of patches has increased while their area has decreased).
 
Conclusion
The results showed that the use of built-up land had the largest area changes during this period and has expanded by 43 hectares, equivalent to 94%, which indicates the intensity of construction. Green spaces have decreased by about 14 hectares, equivalent to 43%, and barren lands, equivalent to 31 hectares, equivalent to 50% of the area's barren lands, have been destroyed and converted to other uses over the past 20 years. The waterways of the Mehran River have also been completely concreted along the route and have been removed from their natural shape by human manipulation. The changes made are mainly of the construction type, and the destroyed lands, especially in the area of Dokamal Street, have been converted into buildings and urban roads. Qualitative analysis of changes also showed that in the Attrition index, 30.55 hectares of land, in the Creation index, 89.75 hectares, and in the Dissection index, 15.74 hectares have experienced these changes, which indicates the fragmentation of the landscape. The results showed that in the Cohesion index, built-up lands have the highest cohesion among the land cover within the area of Dokamal Street. Considering the availability of wasteland around Dokamal Street, a feasibility study was conducted using TerrSet Corridor Planning software to design a 3.6 km long, circular, and connected ecological path with an area of 8 hectares, which, if implemented, could partially compensate for this disruption. These lands are the only potential opportunities for creating a green network on Dokamal Street in Tabriz; therefore, their protection should be prioritized. Because this ecological corridor can be connected to its main core, Baghmisheh Park.
 
Funding
There is no funding support.
 
Authors’ Contribution
Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none.
 
Conflict of Interest
Authors declared no conflict of interest.
 
Acknowledgments
We are grateful to all the scientific consultants of this paper.