Assessment of Ecological Connectivity of Urban Green Patches Using Graph Theory: the Case study of Ahvaz Metropolitan Area

Abstract

Connectivity of urban green patches is an important structural attribute of urban landscape that facilitates the species movement and transfer of their genes among their habitats. So far, several methods including Graph Theory have been applied to assess ecological connectivity. This research was aimed  to study the application of graph theory to measure the connectivity of green patches in the city ofAhvaz .The Graph is a mathematical concept including nodes and links. The research method is based on modeling the network of green patches in the GIS environment using Graph Theory. The ecological connectivity was analyzed using the software Conefor Sensinode 2.6, by applying IIC metric and node-removal algorithm; thus, the urban green patches were ranked in relation to 4 different groups of species. Generally, similar results were achieved by applying the attributes of four different species (r=0.95). The study results showed that Ahvaz fourth district in the eastern side of Karoon River comprised the largest and the most significant green patch. Also, the fourth and fifth distincts of the city were relatively the most connected. Determining the more significant green patches and improving the connectivity of urban landscape could  help the accurate identification of conservation priorities whichwould  ensure financial savings in urban planning and decision making.  

Keywords

• Ecological connectivity
• Network analysis
• IIC metric
• Landscape ecology
• Conefor 2.6
• Ahvaz.