This paper is meant to analyse the natural dynamics of Constanta county in the rural space between 1992-2011. This study is based on the necessity of highlighting the changes in the natural dynamic of the rural population as a result of a gathering of economic, political, social, natural and cultural factors that took place between the studied interval. The analysed rural territory consist of 58 communes that differ from one another from socio-economic point of view, aspect that determines several demographical patterns. A series of indicators (birth rate, mortality rate, natural increase and vitality index) were considered and correlated using data from the censuses of population and the statistical records of the territorial administrative units (communes) in order to reflect the quantitative and qualitative changes in demographic dynamics in rural space analysed.
Abstract: The regions where most of tsunamis originate are Japan, Peru, Chile, the New Guinea and the Solomon Islands. The emergence of tsunamis may be caused by the following factors: 1) earthquakes; 2) volcanic eruptions; 3) rockfalls; 4) landslides; 5) submarine landslides; 6) submarine explosions; 7) meteorological reasons. Damage is caused by: 1) flood due to quick rise of the sea level; 2) dynamic load on constructions; 3) hits by floating wreckages; 4) soil wash-out at foundations by the fast water stream; 5) fluctuations of water level (leading first of all to the damage of vessels moored: 6) dynamic impact of the air wave in front of a tsunami. Tsunamis cause considerable mortality and influence a number of objects and types of human activity: 1) residential and industrial buildings; 2) water transport; 3) plant growing; 4) forestry, etc.
Abstract: Altogether about 2500 volcanoes exist on Earth, and during the last 3500 years, 959 of them erupted. About 360 mln. people live in dangerous proximity to actve volcanoes. On average about 50 volcanoes erupt each year. Catastrophic events may result from six volcanic processes, viz. 1) ejection of rock debris; 2) lava flows; 3) ejection of volcanic gases; 4) burning volcanic clouds; 5) volcanic landslides; 6) lahars. Each eruption manifests itself in several volcanic processes, but only one or two of them may prevail. First of all volcanic eruptions are dangerous for the following human activities: 1) transportation; 2) agriculture; 3) communication & electricity transmission lines; 4) residential building. Average annual mortality from them is about 800 persons and economic loss amount to $800-900 million.