In the last years, environmental monitoring was shown to be a major application field of modern signal processing and machine learning techniques. In particular, it provides some interesting problems for which specific signal processing methods were proposed. In this session, we aim to review some recent advances in this topic. We propose a taxonomy of the major trends in environmental surveillance according to the characteristics of the sensing devices, i.e., (i) for a unique sensor or an array of sensors (e.g., bio-sensor, chemical sensor arrays), (ii) for remote observation, and (iii) using large-scale sensor networks.