Application of remotely sensed data and landscape metrics to understand the impacts of rapid urban expansion on wetland ecosystems

The rapid expansion of urban landscapes in less developed countries is causing severe ecological impacts on important ecosystems such as wetlands. This study aims to integrate multi-temporal remotely sensed data, field data and spatially explicit landscape metrics to understand the impacts of urban expansion on the structure of ecosystems at a small suburban scale. Remotely sensed data are used to monitor changes in the spatial structure of four land use land cover types over a period spanning from 2004 to 2020. The land use land cover classes were extracted from Landsat 5 and Landsat 8 images that were acquired from Google Earth Engine and classified using maximum likelihood supervised classification algorithm. To quantify land use land cover changes, five landscape metrics are used that are edge density, total edge, mean perimeter area ratio, area weighted mean shape index and the number of patches. Results show that landscape metrics used in this study increased between the study period, and this reflects a negative spillover effect of rapid urbanization on the natural landscape, as evidenced by wetland shrinkage and fragmentation. This study provides useful and nuanced quantification of the spatial and temporal dynamics of the urbanization phenomenon and the negative consequences on the wetland ecosystems. This can inform the development of more ecologically sensitive urban planning policies that enhance the integration of wetlands into the city’s land use management framework.