INFLUENCE OF PRECIPITATION UPON DRAINAGE DISCHARGE IN TWO DIFFERENT CLIMATIC REGIONS

The goal of three-year investigations was to determine the influence of precipitation upon the drainage discharge in two different climatic regions (Croatia and Lithuania) at two different pipe drainage spacing in each region (first region with 15 m and 20 m drainage spacing and second region with 12 m and 24 m drainage spacing), to calculate the soil water balance according Thornthwaite's method and compare the measured drainage discharge and the calculated surplus of water in soil. Investigations were carried out at the experimental amelioration sites in the central Sava River Valley (Croatia) on hydroameliorated Gleyic Podzoluvisol soil and in Middle part of Lithuania on hydroameliorated Hypogleyic Luvisol soil in the period 2009 - 2011. The research results showed that the drainage discharge and its duration depended on the amount and distribution of the precipitation during the study period. There isn't difference in the total drainage discharge between the tested drainpipe spacing in each investigation year, but there are differences in the duration of the drainage discharge both on an annual scale and depending on drainpipe spacing. In each year, the duration of drainage discharge was smaller at the 12-15 m drainpipe spacing than at the 18-20 m drainpipe spacing. The calculated surplus of water followed the monthly amounts of precipitation, but in all years was higher than the drainage discharge. The 12 to 15 m pipe spacing is more efficient for draining the surplus water from drained soils, since the surplus of water from soil is drained in a shorter period of time and better water-air relationships in soil are created faster, which is a prerequisite for timely application of agricultural management practices on hydroameliorated arable areas

APPLICATION OF METHODS BASED ON SYNCHROTRON RADIATION FOR SPECIATION OF HEAVY METAL IN SOIL

The study is aimed at analyze atomic and electronic structure of Cu (II) and Pb (II) ions in the artificially contaminated soil and its mineral components using X-ray absorption spectroscopy methods based on synchrotron radiation. Soil sampling was taken in the 0-20 cm topsoil of the Haplic Chernozem of the South Russia. In a model experiment the samples taken were artificially contaminated with higher portions (2000 and 10000 mg/kg) of nitrates and oxides of Cu and Pb. The experimental X-ray absorption (XANES and EXAFS) spectra at the K-edge of Cu and LIII-edge of Pb were performed at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation (Moscow) in the fluorescence regime. The features of XANES spectra indicate different orbital transitions in the electron shells of Pb (II) and Cu (II) ions for monoxide and soluble salt, which affect the ion properties and determine the individual structure of the coordination sphere. Analysis of the EXAFS revealed that Cu (II) ions are incorporated in the octahedral and tetrahedral sites of minerals and bonded with humic materials at the expense of covalent bond and the formation of coordination humate copper complexes. Lead ions in soil are incorporated in the positions of the inner-sphere complex replacing some aluminum ions in the octahedral sites. This results in changes the Pb–O distances in Pb-bearing octahedrons. We may suggest that Pb (II) is also sorbed by dimer (Pb–Pb) silicate and/or aluminum groups

The impact of pipe spacing on drainage of surplus soil water

1 elektroninis optinis diskas (CD-ROM)Agricultural production is very risky on such developed agricultural areas, especially when surplus and/or deficit of precipitation occurs before or during the growing season. Such conditions make production planning very difficult and/or almost impossible, because production, and thereby also yield, depends on weather conditions, making yields of field crops and their quality highly variable. If soil water surplus persists during a long period of time and being the zone of plant roots in a part of the growing period, then the hydro-amelioration measure of drainage should be applied. Drainage of surplus water is an ameliorative procedure that involves the collection and removal of surplus water from soils intended for cropping or some other activity. The goal of three-year investigations was to determine the influence of precipitation upon drainage discharge (runoff) in two different climatic regions (Croatia and Lithuania) at two different pipe drainage spacings in each region; 15 m and 20 m drainage spacing in the first region and 12 m and 18 m drainage spacing in the second region. The researchers calculated soil water balance according Thornthwaite's method, compared the measured drainage discharge and calculated the surplus of water in the soil. The investigations were carried out at the experimental amelioration site in the central Sava Valley (Croatia) and the middle part of Lithuania, in the period 2009- 2011, on hydro-ameliorated Gleyic Podzoluvisol soil and hydro-ameliorated Hypogleyic Luvisol soil. The results show that the drainage discharge and its duration depended on the amount and distribution of precipitation during the study periodVytauto Didžiojo universitetasŽemės ūkio akademij

Climate and aridity change

Vytauto Didžiojo universitetasŽemės ūkio akademij

Influence of precipitation upon drainage runoff in two different climatic regions

Vytauto Didžiojo universitetasŽemės ūkio akademij

Climate changes and soil water regime

The research objective was to determine the duration of dry season based on the frequency of precipitation occurrence both upon 25% (Fa=25%) and 50% (Fa=50%) probability, respectively, for three major climate regions in Croatia (Mediterranean, moutainous and continental). In the Mediterranean region, soil water deficit was 246 mm upon 25% probability of precipitation occurrence. Upon 50% probability of precipitation occurrence, soil water deficit was lower, standing at 191 mm. In both cases, soil water deficit was determined during the summer months and it lasted for three months. In the mountainous region, there was a slight soil moisture deficit, which was 32 mm upon 25% probability of precipitation occurrence and 22 mm upon 50% probability of precipitation occurrence. Soil moisture deficit was determined in July or August. In the continental region, upon 25% probability of precipitation occurrence, soil moisture deficit was 230 mm and the dryness lasted for four months during the summer period, while upon 50% probability of precipitation occurrence, soil moisture deficit was 82 mm. Soil moisture deficit lasted for two months in the summer period (July and August). Higher soil water deficit with longer duration could be predicted in the future against the backdrop of the trend of increasing average annual air temperature in all the regionsVytauto Didžiojo universitetasŽemės ūkio akademij

Aridity and soil moisture deficit trends

A change in climate may cause either or both precipitation and potential evaporation to change. The one binding factor to all arid areas is aridity. Aridity is usually expressed as a function of rainfall and temperature. A useful description of aridity is the following climatic aridity index - P/PET. Climatic data (monthly air temperature and sum of precipitation) for four meteorological stations (Kaunas (Lithuania), Horki (Belarus), Sisak (Croatia) and Sarajevo (Bosnia and Hercegovina) for the period 1996–2016, were used for analysis of agrohydrological balance components by Thornthwaite-Mather method (TM). The movement of temperature and aridity zones could trigger ecosystem migration and land use change. According to the aridity index, based on temperature and rainfall as weather parameters, the climate dryness risk was analyzed. The biggest monthly potential evapotranspiration was in July in all stations in the last 20 years. Monthly soil water balance was found negative in all stations: quantity amount bigger in Sisak and Sarajevo, but continuous longer in Kaunas and Horki. Yearly soil moisture deficit was observed nearly every year at all meteorological stations too. Results showed increasing trends in surface air temperature (in all four meteorological stations) and precipitation (decreasing in Sarajevo). The annual summer P/PET of the study areas varied between 0.6 and 0.9. A drought coefficient has been increasing in Kaunas and Sarajevo in the last 20 years. Information regarding changes in P/ETo index as a result of climate change is necessary for policy makers and managers within the context of water resources management, hydrology, agriculture, and environmentVytauto Didžiojo universitetasŽemės ūkio akademij

Abstracts of The Second Eurasian RISK-2020 Conference and Symposium

This abstract book contains abstracts of the various research ideas presented at The Second Eurasian RISK-2020 Conference and Symposium.The RISK-2020 Conference and Symposium served as a perfect venue for practitioners, engineers, researchers, scientists, managers and decision-makers from all over the world to exchange ideas and technology about the latest innovation developments dealing with risk minimization