Vol. 50 No. 2 (240) (2016)

The processes that lead to the introduction of ophiolites, it is much easier to associate with the displaced protrusions on deep faults, than with the magmatic intrusion (according to classical concepts) or obduction mechanism (under-hypothes of plate tectonics). The tectonic nature of the contact zone of hyperbasites and limestones (where rocks are deformed, brecciated and mylonitied) and the lack of high-temperature contact metamorphism around ophiolites massif are shown. In addition the article presents the petrographic characteristics of hyperbasites.

The paper discusses ore fields of RA with industrial porphyry copper mineralization. The use of conceptual and combined models of ore-magmatic system and ore fields, it is possible to pick out prospective ore occurrences and make some prediction at a depth.

For scientifically solution of the problem of groundwater development in volcanic regions of the Armenian highland we reinterpreted and summarized the long-term data of geophysical studies, including studies made within Aragats volcanic massif. Our drafted summary map of paleorelief of this territory allows one to draw conclusions about the link between modern and paleo-watersheds and on the distribution of groundwater flow in particular within the Selavmastara River basin.

The work is devoted to modeling of landslide slopes and methods of determining the shear strength. Three types of physical and geological models have been distinguished. Based on the results of experimental studies, changes in the formula of the slopes stability assessment have been proposed regarding to slopes composed of clayey soils of solid, semi-solid and tight plastic consistency, where the total value of the cohesion is to be reduced by the value of the hard cementation cohesion. Clay soils of soft plastic and liquid plastic consistency are capable to viscous-plastic and plastic deformations, so that on the slopes, composed of such soils, landslides on the mechanism of formation are plastic landslides or landslide flows. Taking into account that the sliding surface zone has no solid structural links in the formula of evaluating the slope stability the shear strength value should be taken as $\tau_f=\sigma \tan \varphi$․

The article deals with the evaluation of individual components of natural groundwater resources in the framework of the "National Water Program" of the Republic of Armenia. In particular, the law employs terms such as "used ground water resources", "strategic and national reserves of groundwater". There are no such terms in hydrogeological literature, and their statements are missing in the law and there are no methods of evaluating them that are important for rational management of groundwater resources of Armenia. The article provides formulation and methods for assessing these terms with reference to specific watersheds of the rivers of RA.

In the article for the first time the peculiarity of recreational estimation of vegetation of «Lake Arpi» National Park is presented. Researches have been done in three fields, where abundance of medicinal herbs has been valued. In the article the methods, which are more effective for estimation of vegetation, are presented.

The essentials and basics of sustainable tourism are analyzed. New trends, problems and principles of sustainable tourism management are introduced. Environmental, social and economic problems caused by tourism is discussed. It is analyzed that sustainable tourism is not a type of tourism, it is ideological and methodological basis for any kind of tourism activity. The basic directions of sustainable tourism management are related to green-washing, tourism carrying capacity, regional development indicators, value chain, types of tourists, knowledge-based economy, management of cultural heritage, collaboration between university, industry and government.

Alterations of the relief of the territory of Armenia in the process of economic activity of man and forming of secondary technogenic processes, directed to reconstruct the balance of former condition of the relief broken by man, are examined in the article. It is noted that anthropogenic influence on the relief acquires greater scale year by year. It is necessary to give competent forecast of expected secondary processes for professional planning of transformation of existing relief for preventing undesirable consequences.

The article refers to the demonstration of the characteristics of extreme runoff of the rivers in the context of global climate change. The dynamics of changes of the rivers' extreme runoff and air temperatures have been studied, compared and assessed from 1960 till 2012 (case study is the relatively large rivers of Sevan Lake basin). In the studied river-basins are viewed air temperature increase and decrease of absolute maximum extreme runoff of the rivers. Therefore, it turns out that winter temperatures have contributed to a gradual melting of snow accumulated in the river basin causing reduction of absolute maximum runoff in spring. As a result, the risk of occurrence of floods have dramatically reduced.