ANALYSIS OF TRENDS OF TOTAL EVAPORATION FLUXES (FOR 2003-2017) ACCORDING TO THE DATA OF PRODUCT MOD16A2 FOR THE TERRITORY OF THE MARKSOVSKY DISTRICT OF THE SARATOV REGION

This paper presents the results of calculations of areal trends of total evaporation ETa fl uxes for the growing periods of 2003-2017 in the territory of the Marksovsky district of the Saratov region. Raster layers formed for the territory with a 500 m resolution of the Eta8 (Eta 8-day averaging) for each year of the investigated time interval were obtained from tiles sets h20v03 of the product MOD16A2 for the period from May 25 to September 2 of the corresponding year. As a result, the 19830 time series of total evaporation fl uxes for the ETaw growing seasons of the 15-year study period were drawn up for the Marksovsky district. The obtained time series of geodata of the actual evapotranspiration for the growing season ETaw for each of the 15 studied years were used for the spatial analysis of ETaw trends. For the analysis, the method of nonparametric Mann-Kendal statistics was used. It revealed the presence of 2 half-periods with diametrically opposite trends in the dominant part of time series. The fi rst half-period found out negative values (downward) trends and falls on 2003-2010, the second half-period showed positive (upward) trends for 2010-2017. The presented results of the spatial distribution of both trends indicate the presence of an infl uence on ETaw both distance from the bank of R. Volga and anthropogenic factors. Hypotheses for additional analysis are proposed. For the visual deciphering of the places of abnormal values of trends velocities of the both half-periods there were used space photos of high resolution. As a result it was marked that the location of these anomalies corresponded to the location of pivot sprinklers in the territory of the Privolzhskoj irrigation system.

LUKIANETS O.I., GREBІN V.V. TIME DYNAMICS OF WATER BALANCE COMPONENTS IN THE PSEL RIVER BASIN

In the article, in order to identify the generalized role of changes that occurred in the Psel River basin with such climatic indicators as air temperature, amount of precipitation, their form of precipitation, the structure of water bodies feeding, as well as water flow in the modern period, the average water balance for a long-term period was calculated the Psel river basin near the town of Gadyach. In general, the water balance equation shows the ratio of water input and consumption within a river basin, taking into account changes in its reserves over a selected time interval and allows one to assess the relationship of its individual components. In the article identifies changes in the ratio between the inflow (amount of precipitation) and consumption of water (total evaporation and runoff) for two periods – the climatic norm of 1961-1990 and modern 1990-2019. Analysis of the temporal dynamics of the water balance components of the Psel river basin showed that the values of the water balance components within the Psel river basin near the town of Gadyach in the modern period have decreased in comparison with the period of the climatic norm – the amount of precipitation by 6,2%, water flow by 17,5%, evapotranspiration by 1,8%. But, analyzing the relationship between the inflow and outflow of water in the basin for the two study periods 1961-1990 and 1990-2019, it can be stated that during the period of the climatic norm, the percentage of water flow from the total precipitation was greater (coefficient water flow 16.2%) than in the modern period (coefficient water flow 14.2%). With regard to total evaporation in water-balance ratios, its share in the water-balance ratio has increased over the modern period (1990-2019). If during the period of climatic normal (1961-1990) the aridity coefficient was 83.8%, then in the modern period, it is 85.8%. That is, the “redistribution” of the water volumes of atmospheric precipitation took place towards the total evaporation with a decrease in the volume of water used to form the water runoff. For the basin of the river Psel – the city of Gadyach in the modern period on the average ≈ 11 mm (or ≈ 130000000 m3) evaporate instead of replenishment of water resources. In the previous period of 1961-1990, on the contrary, ≈ 12 mm (or 136000000 m3) did not evaporate, but flowed into the water bodies of the basin.

Characterization of the Tunisian petroleum refineries caustic effluent

A heterogeneous spent soda effluent generated from Tunisian petroleum refineries has been filtrated and separated in four solid fractions with a particle diameter of 160 to 100, 100 to 40, 40 to 16 and 16 to 10 µm and the fifth one with diameters < 10 µm obtained after total evaporation of the remained filtrate. Spectroscopic characterizations of the condensed phases by means of X-ray induced photoelectron and IR absorption, as well as pH-metry, potentiometry and stationary voltammetry at Ag2S/Ag electrode studies of the filtrate, show that the whole of the separated fractions contain Na2S, NaHS, C2H5SNa, Na2S2O3, Na2SO3 and methyl, ethyl and propyl mercaptans.

Water needs of interplanted crops on rice irrigation systems

Relevance of research. Recent studies of weather and climatic conditions of the rice-growing zone of Ukraine indicate a steady tendency to increase the aridity of the climate in the region. Further increase in air temperature and decrease in natural water availability of these territories will lead to the increase in total evaporation and water needs for irrigation of the crops of rice crop rotation. Under such conditions a significant exacerbation of the existing problem of water deficit is expected in the region. The availability of water resources directly affects the efficiency of agricultural production on the irrigated lands of rice systems. In this regard, there is an objective need to adapt agricultural production on the irrigated lands of rice systems to the existed and predicted climate change, which, first of all, requires the assessment of water needs for irrigation both the leading crop of flooded rice and the interplanted crops of rice crop rotation. Aim of the study is to estimate the changes in water needs for irrigation of the interplanted crops of rice crop rotation in the variable natural-agro-reclamation conditions of rice system functioning. To achieve this goal, the authors implemented a large-scale computer experiment, based on a complex of predictive-simulation models, which basing on a long-term forecast, allow to estimate weather and climatic conditions, water regime, water regulation technologies and the productivity of reclaimed lands. During the experiment the conditions of total evaporation formation were investigated, the water needs of different types of interplanted crops of rice crop rotation were determined for the technology and regime of water regulation on the irrigated lands of rice systems for the typical groups of vegetation periods of target years in view of general heat and moisture provision. It was evaluated technological efficiency of irrigation of the interplanted crops of rice crop rotation in the variable natural-agro-reclamation conditions of rice system functioning and obtained results with the actual production data were compared. Research methods. The research methods were based on the application of system theory along with the systematic approach, system analysis and modeling oriented on widespread use of computers and related software in the developing of modern approaches to substantiate of technical and technological solutions for water regulation on the drained lands in the conditions of climate change. The object of the study is the Danube rice irrigation systems in Odessa region, design, natural and reclamation conditions of which are typical for the most of rice systems in Ukraine. Results of the study and the main conclusions. During the computer experiment the conditions of total evaporation formation were investigated, the water needs of different types of interplanted crops of rice crop rotation were determined for the technology and regime of water regulation on the irrigated lands of rice systems for the typical groups of vegetation periods of target years in view of general heat and moisture provision. Technological efficiency of irrigation of the interplanted crops of rice crop rotation in the variable natural-agro-reclamation conditions of rice system functioning was evaluated and the obtained results with the actual production data were compared. This approach makes it possible to evaluate and predict water needs for irrigation of the interplanted crops of rice crop rotation in the variable natural-agro-reclamation conditions of rice system functioning. Prospects. The obtained results can be effectively used for justification of regime and technological decisions in the projects of reconstruction and modernization of existing rice systems and developing adaptive measures to the predicted climate change in the region.