According to analyses of results of surveying measurements, description of undefined subsidence, performed with the use of S. Knothe's model is characterised by the sufficient coherence with results of measurements since the moment when the full subsiding trough becomes visible on the terrain surface. Lower coherence with results of measurements appears in the initial period after commencement of exploitation. In order to improve the quality of description within the initial phase of subsidence, a mathematical model has been developed, which is based on relations between the coefficient of the velocity of subsidence and the time co-ordinate, and from geometric co-ordinates. Obtained solutions have been verified basing on results of surveying measurements, with the use of a special computer software.

A failure analysis of Babar dam on the El Arab River was performed to highlight the impact of flood wave and velocities on the four villages downstream of the dam; Hella, Khérenne, Chebla and El Oueldja. The simulation of wave propagation along the El Arab River under several scenarios was performed by the hydraulic HEC-RAS model. This model is dedicated to the description of floods at the dam following a breach in the dike. The main factors considered in this simulation include the level of flood water, the flood hydrograph, and the typical scenario for this breach. The flood risk analysis revealed that the maximum of flood wave flow registered at the breach is (Qmax = 9253.02 m3∙s–1), and is beginning to mitigate downstream of the dam along the El Arab River where it reached at the last village with a low flow (Q = 1110.64 m3∙s–1). This simulation allowed drawing the risk map which showed the areas threatened by flood wave resulting from a total failure of the work, and consequently required a plan of security measures to moderate as much as possible the consequences of floods. A sensitivity analysis was conducted to approach the parameters of impact of the breach on the dam failure scenario. It was confirmed that these parameters as formulation time, breach width and side slope have a great influence on the dam failure scenario with the four adjustments (±20 and ±50).

In 1989/90, in the region of SSSI 8 situated on King George Island 21 bird species were observed, 12 species were breeding. Dominants were 3 Pygoscelis species (19229 pairs). Five species of pinnipedians were noticed. Mirounga leonina was most abundant in January (623 individuals), Arctocephalus gazella — in February and March (890 individuals), Hydrurga leptonyx in October (39 individuals). The abundance of Leptonychotes weddelli was low and rather stable. As a result of mild winter during the study period such birds as Sterna vittata and Pygoscelis adeliae stayed near their breeding places. The scarcity of Lobodon carcinophagus was probably also a result of this mild winter.

The aim of the article is to assess the current image of Poland as a tourist destination from the point of view of the Russians. To achieve the assumed goals, surveys were carried out. Basic statistical indicators such as mean, standard deviation, Pearson similarity index and graphic methods were also used in the study. Russian citizens did not perceive fully Poland as a country attractive for tourists both for themselves and for other European tourists. Their opinion in this regard was more critical than representatives of other nations.

Nairobi International Convention on the Removal of Wrecks came into force on 14th April 2015 and has been ratified by now by over 40 states across the world (among them Australia, China, India, South Africa and most of the EU countries). The convention provides legal framework for action taken by the Coastal States aiming at removal of wrecks posing danger or impediment to navigation, as well as to the marine environment, or damage to the coastline or related interests of one or more States.

The Convention fills the existing legal gap by enabling the States to remove wrecks beyond their territories (as well as within if States decide so). Beside the existing international regulations like Intervention Convention or UNCLOS, the Nairobi Convention clarifies the Costal State’s rights to remove wrecks from its EEZ if they pose a danger for safe navigation or marine environment. The Convention corresponds with mentioned conventions but also equips Coastal States with new legal instruments to deal with hazardous wrecks beyond their territory. The aim of the paper is to analyse the new rights and duties of states, as well as scope of the notion of navigational and environmental threats causes by wrecks. It will refer also to regulatory problems faced by the states implementing the Convention. Even if the Convention is to be applied to territorial sea, its multiple provisions are not. Moreover, the Convention leaves many important aspects unregulated. Those issues will be analysed from the perspective of a country which has not yet ratified the Convention, and will be confronted with the experience from other jurisdictions.