Abstract Volcanic hazard and risk at Soufrière Hills Volcano (SHV), Montserrat has been assessed in a consistent and quantitative manner for 14 years (1997–2011) during highly variable eruptive activity involving andesitic lava-dome growth, which has placed serious constraints on Montserratian society. This work has been carried out by the Scientific Advisory Committee (and predecessors) in collaboration with the Montserrat Volcano Observatory. We describe the organizational context of these assessments, the types of hazards and the methods used to analyse them. Knowledge elicitation using hazard scenarios and analysis by the Classical Model method were employed to formulate probabilistic forecasts of future hazardous events over the next year, and to quantify risks to individuals and Montserrat society generally. We devised a scheme for assessing the likelihood that the volcanic system had stopped receiving basalt magma, considered to be the main driver of the eruption. The accuracy of forecasts was tested using Brier Skill Scores: 83% of forecasts for events that were critical to life had positive skill, as measured by this method. We also discuss how government responded to our assessments. The continuous series of quantitative volcanic hazard and risk assessments described here is the only one of its kind.

Abstract The UK, and England in particular, is the stronghold for chalk rivers, streams and wetlands in Europe. A number of sites are recognized as being important for nature conservation and have been designated as such under UK and European legislation. However, as the chalk is also an important aquifer for southern and eastern England, there have been significant impacts on these groundwater-dependent ecosystems from abstraction. Chalk rivers and streams have been used for centuries for mills and water meadows, so impacts have not just occurred in recent times. Intensification of agriculture in the twentieth century has added to the pressure by increasing levels of pollution, especially nitrates, with significant levels now being recorded. However, moves have been made to resolve some of these issues, with investigations into the effects of abstraction and options for reducing these impacts, research into the nature of the chalk aquifer so that it can be modelled more accurately, and assessment made of pollution pathways and their timescales. Associated projects have characterized the ecosystems associated with the chalk in more detail, enabling the mechanism for impacts to be better understood. While the extent of impacts is increasingly understood, action is also being taken to reduce their effects and restore chalk ecosystems.