Analysis of underwater quality in different Lituanian agro-landscapes

Šiame darbe nagrinėjama požeminio vandens kokybės dinamika skirtinguose Lietuvos regionuose: šiaurės, vidurio, pietų ir pietvakarių. Pagrindinė požeminio vandens kokybės monitoringo užduotis yra kaupti ir vertinti informaciją apie ilgalaikius požeminio vandens išteklių būklės kitimus dėl gamtinių ir antropogeninių veiksnių. Požeminio vandens kokybės analizei buvo pasirinkti Karajimiškio, Lančiūnavos, Išdagų ir Varėnos stabėjimo postų gręžiniai. Analizuojami 2005-2007 m. duomenys. Duomenų analizė parodė, kad požeminio vandens tarša priklauso nuo dirvožemio granuliometrinės sudėties, požeminio vandens slūgsojimo gylio, kritulių kiekio, žemėnaudos. Lietuvos sulfatinio karsto regione, Karajimiškio posto požeminiame vandenyje visais analizuojamais metais nustatyta didžiausia amonio, sulfatų, kalio, kalcio ir magnio koncentracija. Lančiūnavos posto gręžinyje visais analizuojamais metais nustatyta didžiausia nitratų koncentracija. Iš visų analizuotų gręžinių, geriausios kokybės vanduo nustatytas Varėnos posto gręžinyje.The aim of this thesis is to analyse underwater quality dynamics in different Lithuanian regions: northern, middle, southern and south – western. The main task of water quality monitoring is to hill up and estimate information about long-lasting underwater natural recourses condition changes due to natural and anthropogenic factors. Karajimiskis, Lanciunava, Isdagai and Varena observation posts boreholes were chosen for underwater quality analysis. Data period is 2005-2007 y. Data analysis showed that underwater pollution depends on soil composition, waterlogging depth, precipitation quantity, land-tenure. The greatest concentration of ammonium and sulphates were measured in Karajimiskis post. The best water quality was observed in Varena observation post.Žemės ūkio akademijaVytauto Didžiojo universiteta

The change trends of drainage functioning in loamy soil

Vytauto Didžiojo universitetasŽemės ūkio akademij

Drainage Trench Conductivity and Biogenic Materials Retention

eISSN 2029-7092; eISBN 978-609-476-044-0; Article ID: enviro.2017.190In the work, the effectiveness of hydrosystem functioning, when the filtration characteristics of the drainage trench backfill are improved by admixing lime materials, is analysed after a 28-year period of use. The tests of effectiveness of hydrosystem functioning were carried out in the test object of Raseiniai district, Kalnujai. The drainage was installed in the drying systems and the filtration characteristics of trench backfills were improved by admixing the lime material. Analysing the maximum comparative debits of drainage in the control drying systems in the period of spring and autumn 2016 (0.006 and 0.190 ml/s m, respectively) as well as comparative debits in the period of spring and autumn (0.015 and 0.311 ml/s m, respectively) in the drainage, which filtration characteristics of trench backfills were improved by admixing chalkly materials (0,6% ground mass), the results were better by 60.0 and 38.9%, respectively. Assessing the drainage system effectiveness indexes of 2012, 2013 and 2016 with the reliability of 95%, it can be stated that the effectiveness of drainage functioning, when the lime materials were used for the improvement of the filtration characteristics of drainage, did not change essentially after a 28-year period of useVilniaus Gedimino technikos universitetasVytauto Didžiojo universitetasŽemės ūkio akademij

The effect of lime admixture to trench backfill on the functioning of drainage

The study examines the effect of lime admixture to trench backfill on the functioning of tile drainage after almost 25 years of operation. The hydrosystems' efficiency examination was performed at the test site in Kalnujai, Raseiniai District, where filtering capacity of drainage trench backfill had been improved by lime admixture. When analysing the maximum drainage discharge per unit length at the control drainage systems as of spring and autumn of 2012 (0.250 and 0.288 ml/s m respectively), as well as the drainage discharge per unit length as of spring and autumn (0.297 and 0.392 ml/s m respectively) in the drainage, where the trench backfill filtering capacity had been improved with lime admixture (0.6 % of the soil mass), correspondingly 15.2-31.9 % better results were obtained. When evaluating the drainage systems efficiency indicators as of 2003 and 2012 with the 95 % reliability, it can be stated that the efficiency of drainage, where the filtering capacity has been improved with lime admixtures, remained virtually unchanged after almost 25 years of operationVilniaus Gedimino technikos universitetasVytauto Didžiojo universitetasŽemės ūkio akademij

Klimatinių veiksnių įtaka drenažo nuotėkiui, esnat skirtingam humusingo sluoksnio storiui

Sunkių ar suslėgtų dirvožemių hidrofizikines savybes ir vandens režimą galima pagerinti įvairiais būdais, atsižvelgiant į dirvožemio granuliometrinę sudėtį ir klimato sąlygas. Drenažas - priemonė, padedanti našiai ūkininkauti ir gauti ekonominės naudos. Drenažo hidrologinis veikimas dažniausiai priklauso nuo projekto įrengimo kokybės, antropogeninių ir klimato veiksnių. Svarbu įvertinti drenažo veikimą, esant skirtingoms meteorologinėms sąlygoms. Straipsnyje pateikiami apibendrinti tyrimų duomenys apie drenažo nuotėkio dinamiką pastorinto (iki 40-50 cm) ir natūralaus storio (20-30 cm) humusingo sluoksnio velėniniame jauriniame dirvožemyje. Bandymai atlikti 1989-2009 m. LŽŪU Mokymo centro specialiai įrengtame 3,4 ha lauke (Kauno r.). Drenažo nuotėkio kiekis glaudžiai koreliavo su įšalu (RI =0,75, RII= 0,71) bei santykine oro drėgme (RI=0,52, RII= 0,55), silpniausiai - su temperatūra (RI=0,09, RII =0,10). Didžiausi drenažo nuotėkiai formavosi žiemos atlydžių metu bei pavasario polaidžio metuHydrophysical properties of heavy or compressed soils as well as water regime can be improved in various ways considering the soil texture and climatic conditions. Hydrologic performance of drainage often depends on the quality of the installation, anthropogenic and climatic factors. It is important to assess the functioning of the drainage at different meteorological conditions. The article summarizes findings of the drainage flow dynamics in bold (up to 40-50 cm) thick and natural (20-30 cm) layer of sod humus-rich podzolic soils. The experiments were carried out in 1989-2009 at specially equipped field of 3.4 ha of the Training center of the Lithuanian University of Agriculture (Kaunas region). The obtained results show strong correlation of the drainage runoff amount with frozen ground (RI=0.75, RII= 0.71) and relative humidity (RI =0.52, RII= 0.55), while the weakest correlation -with temperature (RI =0.09, RII = 0.10). The biggest amounts of drainage runoff form during winter and spring thawsVytauto Didžiojo universitetasŽemės ūkio akademij

Hydraulic conductivity of drainage ditch backfill with a lime additive in clay soils

Autoriaus atsiųstame pdf klaidingai nurodytas vol. numerisThe efficiency of drainage installed in clay soils using ditch backfill of soil mixed with lime is presented in this paper. The drainage ditch backfill was mixed with lime where 0.6% of soil matter consists of active CaO. The paper proposes a methodology that determines an optimal amount of lime. The experimental site was set in Kalnujai, Raseiniai district, Lithuania. The measurement of filtration in drainage trench, the arable layer and the soil between drains was performed using a double ring infiltrometer. The mean values of the hydraulic conductivity of the arable layer, the soil between drains, the pilot backfill and drainage ditches backfill with a lime additive were respectively 1.66 ± 0.24, 0.65 ± 0.09, 0.94 ± 0.13 m/d and 2.47 ± 0.12 m/d under reliability of 95%. Dispersion analysis on pilot drainage backfill and drainage ditch backfill with lime additive under ditch backfill containing 0.6 % of CaO in soil matter showed that they significantly differ at a reliability of 95%. Thus, the effect of lime on the conductivity of the backfill of the drainage ditch for the following 30-year period of drainage operation in clay soils has remained criticalVilniaus Gedimino technikos universitetasVytauto Didžiojo universitetasŽemės ūkio akademij

Assessing the Hydraulic Conductivity of Open Drainage for Surface Water in Road Safety Zones

The relevance of research on removing surface water from the drained areas has increased along with a rising number of drainage systems. A large part of inlets for surface water are installed in the ditches of road safety zones and / or terrain drops in safety zones where flowing surface water accumulates. The practice of constructing and rebuilding roads in Lithuania shows that each new route of the road section most frequently passes through the drained area and redistributes runoff characteristics of that sector. Each subgrade passing through the watercourse of surface water is a local dam for surface runoff. The surface water that has accumulated in road safety zones have to be drained to avoid damage to road structures and from the flood in the drained roadside areas. The article discusses the efficiency of hydro technical measures such as inlets for surface water in the mining area and highlights the specificities of hydraulic calculations when the complete drainage system for surface water Inlet–Water Drainage Line is integrally assessed. The paper also proposes a methodology for the hydraulic calculations of the system Inlet–Water Drainage Line. The article examines the condition of water inlets having the F-5 or PN-42 structure. The findings of the research carried out in 2017 demonstrate that only 15.3% of inlets for surface water were completely clean, 45.2% of the inlets were found fully contaminated and 39.5% of those were partially silted up. Thus, a clear upward trend towards polluting the cross-sectional areas of inlets for surface water with soil and grass root plants and a strong downward trend towards clean cross-sectional areas of inlets for surface water are observed. 22.6% of inlets for surface water were found damaged by farmers using tillage machinery

Comparison of mortality risk evaluation tools efficacy in critically ill COVID-19 patients

Background: As the COVID-19 pandemic continues, the number of patients admitted to the intensive care unit (ICU) is still increasing. The aim of our article is to estimate which of the conventional ICU mortality risk scores is the most accurate at predicting mortality in COVID-19 patients and to determine how these scores can be used in combination with the 4C Mortality Score. Methods: This was a retrospective study of critically ill COVID-19 patients treated in tertiary reference COVID-19 hospitals during the year 2020. The 4C Mortality Score was calculated upon admission to the hospital. The Simplified Acute Physiology Score (SAPS) II, Acute Physiology and Chronic Health Evaluation (APACHE) II, and Sequential Organ Failure Assessment (SOFA) scores were calculated upon admission to the ICU. Patients were divided into two groups: ICU survivors and ICU non-survivors. Results: A total of 249 patients were included in the study, of which 63.1% were male. The average age of all patients was 61.32 ± 13.3 years. The all-cause ICU mortality ratio was 41.4% (n = 103). To determine the accuracy of the ICU mortality risk scores a ROC-AUC analysis was performed. The most accurate scale was the APACHE II, with an AUC value of 0.772 (95% CI 0.714–0.830; p < 0.001). All of the ICU risk scores and 4C Mortality Score were significant mortality predictors in the univariate regression analysis. The multivariate regression analysis was completed to elucidate which of the scores can be used in combination with the independent predictive value. In the final model, the APACHE II and 4C Mortality Score prevailed. For each point increase in the APACHE II, mortality risk increased by 1.155 (OR 1.155, 95% CI 1.085–1.229; p < 0.001), and for each point increase in the 4C Mortality Score, mortality risk increased by 1.191 (OR 1.191, 95% CI 1.086–1.306; p < 0.001), demonstrating the best overall calibration of the model. Conclusions: The study demonstrated that the APACHE II had the best discrimination of mortality in ICU patients. Both the APACHE II and 4C Mortality Score independently predict mortality risk and can be used concomitantly