Landslide risk mitigation: challenge or strategy? As a consequence of climate change and the increase in exposure in many parts of the world, the risk associated with landslides is growing. The challenge is to improve the understanding of landslide triggers and runout and the ability to estimate landslide hazards and risks and develop a framework for quantitative risk assessment for different landslide mechanisms and different scales and intensity of sliding. Developing risk management tools and guidelines we could choose the appropriate risk mitigation strategy by involving the stakeholders.

Expansive soils contain minerals such as smectite clays that are capable of absorbing water. When they absorb water, they increase in volume. The more water they absorb, the more their volume increases. Cracked foundations, floors, and basement walls are typical types of damage done by swelling soils. Expansive soils will also shrink when they dry out. This shrinkage can remove support from buildings or other structures and result in damaging subsidence. Expansive soils generally do not cause problems if their water content remains constant. The situation where the greatest damage occurs is when there are significant and repeated moisture content changes. Expansive soils are present throughout the world and they cause billions of euros in damage every year. They are known in Romania as well. The lecture presents high and very high expansive soils for the city of Iaşi, in the north-eastern part of Romania. The lecture answers the question "how to build safely on expansive soils" explaining how to maintain the moisture content or insulating the building from any soil volume change that might occur.

There are many different kinds of hazards associated with volcanic eruptions, depending on the type of volcano and eruption. Some volcanoes typically produce highly explosive eruptions, others produce less energetic eruptions. A volcanic hazard is a probability that a volcanic eruption or related geophysical event will occur in a given geographic area and within a specified window of time. The risk that can be associated with a volcanic hazard depends on the proximity and vulnerability of an asset or a population of people near to where a volcanic event might occur.

About 50,000 earthquakes large enough to be noticed without the aid of instruments occur annually over the entire Earth. Of these, approximately 100 are of sufficient size to produce substantial damage if their centres are near areas of habitation. Over the centuries they have been responsible for millions of deaths and an incalculable amount of damage to property. For us, the inhabitants of Iasi City, Romania, the earthquakes are near us. Most of the hazards to people come from man-made structures themselves and the shaking they receive from the earthquake. 

Observations show that most earthquakes are associated with tectonic plates boundaries. The theory of plate tectonics can be used to provide a simplified explanation of the global distribution of earthquakes, while some of the characteristics of earthquakes can be explained as well. In much the same way that geographic borders have separated, collided, and been redrawn throughout human history, tectonic plate boundaries have diverged, converged, and reshaped the Earth throughout its geologic history. Today, science has shown that the surface of the Earth is in a constant state of change. We are able to observe and measure some of the environmental hazards: mountains rising and eroding, oceans expanding and shrinking, volcanoes erupting and earthquakes striking.