Interconnected ecological network design using lcp algorithm and cohesion index in urban scale

Abstract

The structure of interconnected ecological network in cities includes corridors and large green spots continuity which provides ecosystem services, e.g. biodiversity conservation. From a functional perspective, green infrastructure would be one of the most adapted ways of solving environmental issues caused by restricted vegetation in intensive urban areas with high density of gray infrastructures. In this study, green infrastructures of Hamadan with an area of ​​about 74.22 km2 across 75 districts, (including agricultural lands, Parks, gardens and vacant lands) were classified as Service Providing Units (SPUs). Gardens and parks classes with dense tree cover as well as high ecosystem standards, were selected as green habitat patches, including 205 patches in the study area. Considering the highest quality of habitats, 14 patches were chosen as habitat cores based on having the highest level of COHESION metric, and the area of more than 12 ha. We performed the Least Cost Path (LCP) method through QGIS software at the study area to see core habitats connectivity; using a simple algorithm to calculate the cumulative cost of moving through landscape. Results show that a total of 91 potential corridors were identified connecting the main cores. Optimal corridor selection was based on two scenarios, the shortest and the least costly route. Therefore 23 and 54 corridors were selected. By combination of two scenarios and considering the overlap of some routes, the final corridors were also identified. To keep up network connectivity, in the case of Corridor 6–9 with high costs over threshold, stepping-stones have been defined to reduce costs and distance.