The increase of artificial light in recent decades has led to a general awareness of the harmful consequences of light pollution on biodiversity. The artificial light is however rarely taken into account in the principles of developing ecological networks. There is currently no standardized method for integrating this darkness factor into ecological network modeling. We propose a methodology for the identification of the nocturnal continuum through an approach based on the automated extraction of light sources from nocturnal orthophotography and the modeling of their visibility within a territory. The model is applied to the transboundary region of the Geneva basin in Switzerland and allows for the integration of the darkness factor into the existing ecological networks. Although the analysis does not consider metric lighting data, a viewshed analysis allows for a first large-scale mapping of the nighttime continuum and highlights the areas benefiting from very low light pollution.