The impact of human activities over the environment experienced a dramatic growth in the last century often giving rise to unpredictable effects. As a matter of fact, the impact of un-regulated industrial activities over the last century has induced severe variations in the atmosphere resulting in changes in weather manifestations which, in turn, increased the risk of hurricanes, excessive rain precipitations and so on. Joint to these aspects, wild urbanization of wide areas surrounding the cities exasperates the hazards deriving from landslides, floods, fire in the green areas, etc.. The management of environmental hazard could strongly benefit from the advances in electronics, telecommunications and informatics, often related as Information and Communication Technologies (ICT), which made available a wealth of sensors of different type which can be suitably employed in early monitoring and risk assessment and management. Advanced environmental risk management requires high performance integrated multi-sensor systems enabling fast and accurate detection of disparate data and critical situations that must then be analyzed through scientific modeling and intelligent supervisory interpretation, in order to devise and put at work correct strategies for monitoring and contrasting wild land fires, landslides, floods and varied similar natural hazards. Multi-sensor data fusion and integration still seems a relevant technological challenge when dealing with such complex devices as Thermal/IR imaging systems, radar/lidars, sophisticated Visible cameras, plus the emerging distributed wireless sensor networks (WSN) - with embedded sensing, computing and communication capabilities per each node - that may collect simple weather/hydro/chemical measures on the field under observation. This short exposition makes an assessment of the technology advances in integrated multi-sensor networks, starting by the illustration of the structure and some preliminary results of the ERMES Project (Enhance Risk Management through Extended Sensors), sponsored by the Italian government under grant #PON01-03113.