Vol 38, No 1 (2017)

Pacific Russia is regarded as an aquaterritorial macroregion in the composition of the Far Eastern Federal District and the adjacent sea area within the 200-nautical mile Exclusive Economic Zone. The macroregion harbors enormous natural land and sea resource wealth potential and is endowed with possibilities of using the sea transport connecting Russia and Europe with countries of the Asia-Pacific Region. In Pacific Russia, two latitudinal zones, northern and southern, are identified; they include the territories of the constituent entities of the Far Eastern Federal District. Combinations of the kinds of activity for the constituent entities and latitudinal zones are treated as territorial structures of the economy. An assessment of the geographical differentiation of the economy in the latitudinal zones for the years 2004 and 2013 and its change was made from the differences of the homogeneous kinds of activity in the constituent entities measured in terms of the added value. Structural gradients of spatial (including latitudinal) differentiation of the homogeneous kinds of economic activity are suggested for neighboring constituent entities. The analysis made for the latitudinal zones can be useful in assessing the variants of investment in the economy of the constituent entities of Pacific Russia.

A detailed analysis is made of the current ideas concerning floods of a special type. We examine short-lasting torrential flash floods, one of the most widespread and hazardous natural phenomena in the world characterized by a high rate of development, and by a short duration. It is established that such floods are in a primitive stage of study, which is testified by the fact that there is no general consensus as to what should be treated as a flash flood. It is pointed out that a special term designating them is also absent in many countries. It is determined that the key formation conditions for flash floods include intense short-lasting cloudbursts, the occurrence of a river basin in mountainous regions and a small drainage area; on this basis, it is suggested that they be termed flash floods. It is shown that such floods are of the most widespread occurrence in the northern hemisphere in regions with a temperate and subtropical climate. We suggest the scheme of natural factors for formation of flash floods and their differences from debris flows and floods of other types. It is determined that the main problems of investigating the formation mechanisms and forecasting the aforementioned floods are associated with the small spatiotemporal scale of these phenomena.

An analysis is made of the geobotanical forecasting technique. Mapping is known to be recognized as the most powerful method of forecasting-geobotanical investigations. A close interrelation between geobotanical forecasting and vegetation mapping is demonstrated. To improve objectivity of the findings used cartographic models of modern and predicted vegetation which most fully represent the entire structuralcenotic diversity of plant communities in Prebaikalia, the central region of Baikalian Siberia. The predictive constructions are based on analyzing modern vegetation which always includes structural features of its future that manifest themselves in primary and stable derivative communities. We developed the legend and compiled the map (sc 1:200 000) of the region’s modern vegetation. The state of the natural environment of the Lena- Angara interfluve is assessed having regard to the various functions of plant communities in geosystems. The 1:200 000 map of probability-forecasted (within 200 years) vegetation is presented for Lena-Angara interfluve. It is shown that complete recovery of the primary structure will not occur within 200 years. It is found that it is necessary to carry out predictive-cartographic investigations for the whole of Baikalian Siberia as vegetation of this region is characterized by a decreased activity of recovery processes occurring under the influence of anthropogenic factors. The reason has to do with the harsh natural conditions where it is not worthwhile to pursue extensive nature management, such as is universally the case to date, leading to undesirable economic consequences, because the degree of disturbance to vegetation in a number of areas of Prebaikalia has now reached as critical level. It is concluded that a further policy of nature management on this territory must be built upon the new principles to be approved by government documents.

On the basis of analyzing the ecological problems of the Northwest Pacific region, we suggest environmental objectives, the attainment of which is to ensure a good marine environment status in the region which is a necessary condition for sustainable nature management. We discuss the operational goals and quantitative criteria and indicators as required for monitoring the current status of ecosystems as well as the progress in achieving the objectives. An analysis is made of experience in using a similar approach in the European Union. It is shown that there is a difference of the environmental status monitoring techniques in the Northwest Pacific region where cooperative efforts on rationalization of nature management are not supported legislatively. In dealing with this problem, a special role would be played by regional and international cooperation, specifically within the United National Environment Programme in the Northwest Pacific region, contributing to a harmonization of the national monitoring systems. The need for international cooperation is also dictated by the irregularity of natural and socioeconomic conditions in the region, which makes the development of unified assessment methods difficult.

We examine the ecological aspects concerning the status of the surface waters in the delta of the Selenga river for the low-water conditions which have been observed since 1996. The ongoing changes in the most important indicators of the status of the waters in the river delta are assessed on the basis of results of hydrological, hydrochemical and hydrobiological investigations made by these authors in 2013–2015 and with consideration for earlier research efforts. It is established that the low-water conditions resulted in a decrease of the role of the main delta branches, Kharauz and Levoberezhnaya, in streamflow. An increase in the contribution of groundwater in the alimentation of the river led to an increase in concentrations of main ions: for the current low-water period their total content has varied from 119 to 780 mg/L, with a maximum in small delta branches in the wintertime. Changes in concentrations of biogenic elements were recorded: total phosphorus from 10 to 190 μg P/L, mineral phosphorus from 0 to 35 μg P/L, and nitrate nitrogen from 0.01 to 0.81 μg N/L. A minimum of mineral phosphorus compounds and nitrogen was observed at the time of mass development of algae. It is established that the dynamics of organic matter content is determined by changes in hydraulicity, and by the intensity of phytoplankton development. Within the long-term context, a deterioration of water regime and vegetation infill and swamping of shallow delta branches were recorded. The development level of the phytoplankton and changes in its structure point to a progressive eutrophication of the Selenga waters. According to the value of the saprobic index, the quality of the Selenga waters corresponds largely to the category of “moderately polluted” waters (class II and III), and it decreases at low-water periods, especially in shallow delta branches with a high population of cryptophytic algae, to the category of “polluted” waters.

We examine the decadal (2001–2010) regularities in the processes of distant transport of air masses and heavy metals (HM) to five locations in the North of the European territory of Russia. The spatial and seasonal differences in these processes are considered. We use the back trajectories statistical method for the transport of air masses, and a model description of the distant transport of HM on submicron aerosol particles. The study revealed the most significant sources of HM metals in different seasons for different regions, namely the industrial centers of Murmansk and Arkhangelsk oblasts, as well as the more distant Sverdlovsk, Leningrad and Vologda oblasts, and the cities of Kirov, Perm and Norilsk. The mean indicators of anthropogenic environmental pollution in the background areas of Murmansk and Arkhangelsk oblasts at a large distance from the emission sources. The estimates obtained for lead and cadmium are in a reasonable agreement with available measurements. It is shown that it is only with high winter-summer ratios of anthropogenic HM concentration (higher than 170, which corresponds to about 50% of cases) that anthropogenic impacts on the environment in a warm season can be neglected in the areas under consideration. Otherwise 14 to 45% of the anthropogenic annual flow of HM from the atmosphere can be deposited on the snow-free surface of soils and water bodies. It is found that a combination of the effectivenesses of sources and sinks during the distant transport of HM leads to uneven pollution of the territory under consideration, and this must be taken into account when selecting so-called background (low-pollution) areas separately for each pollutant involved.

Natural regularities were revealed in the development of irrigated agriculture in ancient Tuva, suggesting that the region of Central Asia was home to an ancient agricultural civilization. The study identified ample evidence of ancient irrigation on desert landscapes of the Ubsunurskaya depression, large plots of arable land exceeding considerably the areas of today’s agriculture. It was established that the irrigation systems along the valley of the Tes-Khem river show abundant evidence of ancient settlements. Arid territories of Central Asia–regions of traditional animal husbandry are considered. A town of ancient farmers, hitherto virtually unknown to science, was discovered on the western shore of Lake Ubsu-Nur. Remnants of irrigation systems were investigated, and it was found that separate plots of land were concentrated on low-level peatbogs which were good arable lands. Paleobotanical analysis of peatbogs and buried soil horizons determined the character of vegetation cover on the study territory, pointing to a stable development of vegetation of the foreststeppe type in the past. Wheat and millet grains were discovered, which confirm the existence of agriculture in these areas. Macroremains of forest and forest-steppe vegetation suggest that at the time of ancient agriculture there occurred plant communities on desert landscapes of the Ubsunurskaya depression. It is established that deforestation was among the reasons behind the desertification of this territory.