Evaluation of Water Content in Soils of Žitný Ostrov from the Point of View of Its Exploitation for Biosphere

The lithospheric zone between the soil surface and the first ground water horizon, respectively the ground water table, has a character of three-phase system. It consists of solid phase having fine to rough disperse granularity. This creates a structure of porous environment with characters that can be physically determined. The water occurs in pores in different forms of state and its bond with solid phase. Its energetic bond is clearly quantified by means of moisture retention curve. The gas phase fills pores with the water up to the value of the full porosity, i.e. it fills the part of pores that is not saturated with water. Therefore, this lithospheric zone is called the soil aeration zone. The volume of water occurring in the soil aeration zone corresponds to the concentration of water in the framework of hydrological cycle components. This water serves as the water resource for the vegetation cover. The data used for calculation were particular soil types in the area, depth of ground water table, hydrolimits (wilting point, point of decreased availability, field water capacity) and aeration zone thickness. The water content in the soil aeration zone between hydrolimits field water capacity (FWC) and wilting point (WP) is the critical interval of water content for vegetation cover in a given locality. Water from this interval is available for the vegetation cover. This water has no properties of free water, and plants have to have a developed root system and such suction pressure, that is able to overcome the bond between water and soil. Calculated results were verified with the help of monitored water content. Both calculated and measured values of soil water content in the aeration zone show that the water content is affected by appurtenant soil type. The human activity in a landscape directly affects the dynamics of this water resource, either from quantitative or qualitative viewpoint. This affect is demonstrated by changes of the ground water regime, i.e. changes of ground water table and amplitude of its fluctuation. The paper brings results of water content evaluation in the soil aeration zone in the Žitný ostrov area.

Features of the distribution of molecular hydrogen in groundwater in various geological and tectonic conditions of Uzbekistan

As a result of generalization and analysis of previously performed work on the determination of hydrogen on the day surface, a picture of the distribution of hydrogen concentration in the aeration zone was obtained. The increased concentration of hydrogen on the day surface and in the aeration, zone is associated with the most favourable conditions for the transit of fluids from the folded Palaeozoic basement to the surface cover (upper part of the Earth’s crust). These zones are zones of active fluid conductivity, which leads to a high concentration of hydrogen on the day surface. Intense linear anomalies are confined to the zone of intersection of the Tuzkoy-Rometan transverse fault with the Bukhara-Gissar regional fault, with which seismic events are associated (epicentres Gazli earthquakes occurred 08.04.1976, 17.05.1976 and 19.03.1984). Analysis of long-term observations of gas composition on an example of molecular hydrogen in groundwater southwestern part Karzhantaus fault, covering the territory of Tashkent city and its surroundings, obtained hydrogen concentration distribution pattern area. A different concentration of hydrogen in the fault zone was revealed, associated with the heterogeneity of the geological and structural structure.

On the existence of the resolvent and separability of a class of the Korteweg-de Vriese type linear singular operators

Partial differential equations of the third order are the basis of mathematical models of many phenomena and processes, such as the phenomenon of energy transfer of hydrolysis of adenosine triphosphate molecules along protein molecules in the form of solitary waves, i.e. solitons, the process of transferring soil moisture in the aeration zone, taking into account its movement against the moisture potential. In particular, this class includes the nonlinear Korteweg-de Vries equation, which is the main equation of modern mathematical physics. It is known that various problems have been studied for the Korteweg-de Vries equation and many fundamental results obtained. In this paper, issues about the existence of a resolvent and separability (maximum smoothness of solutions) of a class of linear singular operators of the Korteweg-de Vries type in the case of an unbounded domain with strongly increasing coefficients are investigated.

ECOLOGICAL APPROACH TO THE CONSIDERATION OF THE PROTECTIVE FUNCTIONS OF THE UNSATURATED ZONE

В статье на основе анализа формирования потоков влаги в ландшафтах предлагается рассматривать зону аэрации как природный объект - экологический демпфер. Экологические демпферы- это природные или антропогенно-природные образования, имеющие дополнительное сопротивление потоку и высокое значение ассимиляционной емкости, позволяющие сглаживать (гасить) результаты интенсивных изменений процессов переноса водных или воздушных масс, происходящих на границе объекта. Показаны границы зоны аэрации и формирование водного режима. In the article, based on the analysis of the formation of moisture flows in landscapes, it is proposed to consider the aeration zone as a natural object - an ecological damper. Environmental dampers are natural or anthropogenic-natural formations that have additional resistance to flow and a high value of assimilation capacity, which make it possible to smooth out (damp) the results of intensive changes in the processes of transfer of water or air masses occurring at the boundary of the object. The boundaries of the aeration zone and the formation of the water regime are shown.

ECOLOGICAL ASPECTS OF AUTOMATED REGULATION OF MOISTURE IN IRRIGATED SOILS

В статье рассматриваются вопросы влияния орошения на компоненты природной среды. Показано, что орошение в существенной мере увеличивает водную нагрузку на территорию, что приводит к трансформации водного режима почв, пород зоны аэрации, увеличению инфильтрационного питания грунтовых вод, изменению качества поверхностного и подземного стока. Автоматизированные системы контроля водного режима орошаемых почв позволяют синхронизировать водоподачу на поле с биологическими особенностями водопотребления культур, что в существенной мере позволит снизить водную нагрузку на экологические условия. The article discusses the impact of irrigation on the components of the natural environment. It is shown that irrigation significantly increases the water load on the territory, which leads to the transformation of the water regime of soils, rocks of the aeration zone, an increase in the infiltration feeding of groundwater, and a change in the quality of surface and underground runoff. Automated control systems for the water regime of irrigated soils allow synchronizing water supply to the field with the biological characteristics of water consumption of crops, which will significantly reduce the water load on environmental conditions.

REGULARITIES OF CHANGES IN THE ELEMENTS OF THE WATER BALANCE OF THE AERATION ZONE WHEN WATERING TABLE CARROTS

The subject of research is the study of the regularity of changes in the elements of the water balance of the aeration zone and the root layer, to preserve the fertility of sod-podzolic soils of the Central Russian province of the Non-Chernozem zone of Russia and to obtain optimally high yields of table carrots.

GEOLOGICAL STRUCTURE OF SOILS AND RICE YIELD IN THE ILI RIVER BASIN

Rice irrigation systems in Kazakhstan are located on river terraces and levees of the Syr Darya, Ile, and Karatal rivers’ basins. The geological structure and lithological composition of soils in the aeration zone is characterized by a wide variety, differing in soil fertility, mechanical composition, water and physical properties, water availability and salinity. Alluvial-meadow and takyr soils consist of light and heavy loam, sandy loam, and clay [1,2,3]. Melioration errors of the rice irrigation systems, built in the period from 60s to 80s of the last century, can be described by the fact that the Kubanskaya rice sowing map was built on all soils of river terraces and river banks, with the same parameters of irrigation and drainage, with the share of rice 57.5% and 63% [4]. At the rice irrigation systems, where the geological structure and lithological composition of the aeration zone soils correspond to the irrigation and drainage parameters of the Kubanskaya rice sowing map, the soil fertility and ameliorative status of irrigated land has remained high for many decades. The salt content in the 100 cm soil layer is 0.3-0.4%; in the autumn-winter period ground water is at a depth of 2.0-2.5 m, its mineralization is 5-7 g/l. During the rice irrigation period, ground water does not connect with the water of rice paddies, and the filtration of water from rice paddies is permitted and comprises 12 – 17 mm/day. Rice is grown without flow and discharge of water from rice paddies, the irrigation rate is 21,400 m3/ha, and the yield is 5.2 t/ha. At the rice irrigation systems, where the geological structure and lithological composition of the soil in the aeration zone does not correspond to the irrigation and drainage parameters of the Kubanskaya rice sowing map, the land is saline. During the rice irrigation period, the ground water connects with the water on the rice paddies. On these paddies, due to the convective diffusion of salts from the soil and from ground water, water salinity increases and reaches the critical threshold of toxicity of 2.5 g/l [5]. It is necessary to discharge water to reduce the salinity of water on the rice paddies, which is followed by flooding of water from the irrigation channel. The irrigation rate is 23,500 m3/ha, and the yield is 4.7 t/ha.