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VOLUME 15(37)CONTENT
ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) ECONOMICAL RESEARCH OF FARMS LAND TENURES REORGANIZATIONAudrius ALEKNAVIČIUS, Lithuanian University of AgricultureSummaryFormation of land tenures during the land reform in Lithuania was based on restitution of ownership rights. Afterwards the land tenures can be expanded or reallocated. The expansion of private farm tenures is economically effective and possible, when the profit from increased size of tenures is greater than the cost of transaction or rent of additional land plots. The changes of boundaries and location of land tenures in land consolidation projects must be based on cost-benefit calculations and grounded economically. Calculations must include additional normative cost for production, transportation costs and normative profit. The normative profit from additional production must be greater than rent and capitalized profit must be greater than the price of additional land plot. The role of land management is important while improving land plots configuration and prolonging the arable section and projecting expansion of land tenures. These changes allows to reduce: - the normative production costs for fuel and payment for work: prolonging the arable section from 200...300 m. till 300...400 m. and improving the shape of land tenure for sugar beets in average production cost reduces 22 - 30 Lt/ha. - transportation costs: 18,5...26 Lt/ha for 1 km. Keywords: landuse, expansion, standard expenditure, transportation costs, amendment coeficients, economic effect.
Article received 2001 04, given to print 2001 06. ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE INFLUENCE OF CALCAREOUS SAPROPEL AND LIMESTONE ON SODDY-PODZOLIC SANDY LOAM SOILEugenija BAKŠIENĖ, Voke Branch of Lithuanian Institute of AgricultureSummaryIn the Voke Branch of the Lithuanian Institute of Agriculture experiments were conducted in 1994 to study the efficiency of calcareous, sapropel and limestone in soddy-podzolic sandy loam soils. In the trials were studied the effect sapropel and limestone and its mixtures with other organic (manure, sewage) and mineral fertilizers on the productivity of crop rotation and changes of agrochemical and physical properties in the soil. The calcareous sapropel - manure mixtures increased the productivity of crop rotation more than limestone - manure mixtures. The sapropel as limestone reduced acidity on sandy loamy soil. The amount of total nitrogen and humus changed slightly. From calcareous sapropel and limestone decreased amount of mobile phosphorus and potassium in the soil.The application of sapropel increased the soil moisture and porosity and decreased soil density . Keywords: sapropel, limestone, yield, soil, properties.
Article received 2001 06, given to print 2001 08 20. ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) EVALUATION METHOD AND ITS` DEVELOPMENT ON THE CONDITION OF GRAVELED ROADSBenius BENDARAVIČIUS, Lithuanian University of AgricultureSummaryLocal roads with the gravel cover from Kaunas region Noreikiškės monitory have been evaluated as satisfactory ones, while using the method of evaluation of gravelled roads, prepared by Vilnius Gediminas Technical University. In order to improve the condition of roads it is necessary to fulfil observation, repair and, if necessary, reconstruction works. Having in mind the difficult economical situation, more attention should be paid to observation works, especially to the steady observation of the road cover. The relevance of evaluation methods of the condition of gravelled roads is discussed in the article. It has been noticed that this method not fully and unreliably estimates all parameters and therefore it should be improved. Evaluation rates such as: the amount of fry in the gravel cover, filtration coefficient of the sand bed, the steep of the slopes of ground bed should be corrected in this evaluation method and evaluation rates such as: bump roads, wavy roads - should be joint into one evaluation rate. It has been offered to introduce additionally such evaluation rates: longitudinal slope of the road, horizontal curves, sight, additional road systems for the detailed evaluation of road condition, especially if reconstruction works are being planned. Keywords: road, road condition, evaluation method.
Article received 2001 05, given to print 2001 08. ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) DIRECT INVESTIGATIONS OF SEDIMENTATION IN THE UPPER BASIN OF KRUONIS PSHPAlfonsas DARBUTAS, Jonas JUODIS, Bronislovas RUPLYS, Lithuanian University of AgricultureSummaryIn the paper a preliminary analysis of the sedimentation in the upper basin (UB) of the Kruonis PSHP (pumped storage hydropower plant) is carried out based on investigations of undisturbed sediment + soil samples from the UB bottom. Investigations were carried out in 1997...1999. The sampler of our construction was used; samples were taken from ice (in 1997 and 1999) and from a boat (in 1998). Sediment thickness, grain size distributions and soil types were determined. Complexity of the sedimentation process in the UB and a necessity to continue investigations of the undisturbed sediment + soil samples from the UB bottom of the Kruonis PSHP is emphasized. Keywords: sedimentation, sediment+soil samples, granuliometric composition.
Article received 2001 01, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) EVALUATION OF APPLICATION OF ONE-DIMENSIONAL DIGITAL HYDRODYNAMICAL MODEL FOR FLOOD MAPPING IN THE NEMUNAS DELTA AREAAntanas DUMBRAUSKAS, Arvydas ŠIKŠNYS, Lithuanian University of AgricultureSummaryThe main task of this paper was to estimate the possibilities of application of one-dimensional hydrodynamic model for flood mapping of the Nemunas delta. For this purpose the software package HEC-RAS was developed in the US Army Corps Hydrological Engineering Centre. Geometry and hydro dynamical data for model input were obtained from digital terrain model created by authors using interface HEC-GEORAS and ArcWiev. Model calibration was performed using observed data (water levels and discharges) published in yearbooks of Lithuanian Hydro meteorological service and obtained by authors at the study area in separate reaches of the river. Additional procedure of model calibration was performed comparing digital maps obtained from the model with the map from satellite image. The paper presents the results of simulated scenarios for discharges of different probabilities and possibilities of real time forecasting, possibilities of application of maps of inundated areas for estimation of risk level in the area and perspectives of digital maps in solving of other problems in the Nemunas delta area. Keywords: floods, GIS, modelling, flooded areas, prognosis.
Article received 2001 02, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE TECHNICAL-ECONOMICAL ANALYSIS OF FARM LAND MANAGEMENT PROJECTSVirginija GURSKIENĖ, Lithuanian University of AgricultureSummaryFarmers, agricultural enterprises and other users of agricultural land face many problems in production planning. The ways of rational land usage could be suggested in the farm land management projects. Properly planned usage of the land should ensure the necessary level of agricultural production, soil protection, ecological stability of the territory, increasing quality of farming lands. Economical, ecological and technical substantiation of prepared farm land management projects is necessary. Recommendations for the technical-economical substantiation of farm land management projects are presented in the article. It is purposeful to evaluate industrial possibilities and technological characteristics of cultivated land and designed plots (during land management works) in the following ways: the configuration of land plot, area, the incline of place, stones, soil characteristics and distances of transportation. The worse are the characteristics of cultivated land plots, the larger are expenses for the growing of agricultural plants. Change coefficients of expenses for the growing of the main agricultural plants are established in the evaluation of characteristics of agricultural plots under the conditions of Middle Lithuania. (The author suggests change coefficients of expenses because of the configuration and size of the plot. The influence of characteristics of other plots is suggested to be evaluated according to coefficients presented by S. Volkov). Technical-economical substantiation of farm land management projects includes calculation of the consolidated change coefficient of expenses and evaluation of industrial and technological characteristics of land plots. To have monetary expression of the evaluation, standard expenses for the growth of agricultural plants (in Lt) are multiplied by the consolidated coefficient. Keywords: plot of cultivated land, substantiation of the project.
Article received 2001 04, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE EFFICIENCY RESEARCH OF POLLUTANT REMOVAL FROM WASTEWATER IN THREE-CHAMBER SEPTIC TANKS ARRANGED IN FARMSTEADSAlbinas KUSTA, Lithuanian University of Agriculture, Sigita Marija STRUSEVIČIENĖ, Zenonas STRUSEVIČIUS, Lithuanian Institute of Water ManagementSummaryArranging wastewater treatment facilities in individual farmsteads the septic tanks are necessary for the primary processing of wastewater. In a septic tank wastewater is partly purified and clarified. The sediment accumulating on the bottom of a septic tank gets mineralised and denser, therefore there is a necessity for the cleaning of a septic tank every two years on average. We have been investigated the retention efficiency of wastewater of farmsteads, when this wastewater flows through a three-chamber septic tank. Carrying out the researches on wastewater from cattle-breeding farmsteads we have established that this kind of wastewater contains 3-4 - times more pollutants than household wastes do. Although dairy-farms are provided with modern milkers and refrigerating equipment, wastewater here contains the greatest amount of pollutants. In a farmstead wastewater flows through a sewerage network 1.75...2.67 h per 24-hours, therefore the uneven-hour coefficient Khmaks is very high and fluctuates from 9.4 to 15.46. Approximately 55...70% of the total wastewater amount are hold up in the first chamber of a septic-tank. The other two chambers hold up about 30...45% of wastewater, with the exception for nitrogen, the amount of which is the same in all three chambers. The amounts of various pollutants hold up in a septic tank are different: the quantity of sediments is the biggest one - 48...75.2%, the quantity of nitrogen is the smallest one - 21.1...32.9%. The amounts of organic pollutants (in view to BOD7 and CHDSCr) hold up in a septic tank are 40.0...52.7%. Keywords: runoff, septic tank, anaerobical environment, purification efficiency
Article received 2001 04, given to print 2001 08 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE ANALYSIS OF POSSIBILITIES OF THE EMPLOYMENT OF DISTANCE RESEARCH METHOD FOR LAND-USE ESTIMATIONSaulius KUTRA, Laima BERANKIENĖ, Lithuanian Institute of Water ManagementSummaryIn the research paper there is analyzed the land-use determination under the conditions of Lithuania applying two LANDSAT satellite imager obtained in spring (2000 04 30) and in summer (1992 06 02). Areas with different vegetation cover were chosen for this purpose, and statistical characteristics of spectral reflections were established, in order this data could be applied for land-use classification. The remote sensing method is widely applied for land-use determination as well as for other objectives in foreign countries. Our researches carried out in Lithuania are only the first attempts the ultimate goal of which is to make up land-use maps necessary for environmental problems to solve with the help of satellite images. The research data has shown that the interpretation of satellite imager spectral reflection is probably one of the most complicated points of remote sensing. In the paper the attempts were made on the possibilities of vegetation types setting apart by statistical analysis, normalized distance between the means and divergence. In spring only bare ground (soil) becomes most distinct (100% probability in 1 and 3 spectral zones), in the spectral zones 3 and 4 it is possible to distinguish a forest and a meadow (even 95% probability) and in the zones 3 and 4 a meadow becomes distinct from winter crops (68% probability). Seeking to determine the land-use more precisely it is necessary to investigate the peculiarities of Lithuanian vegetation and to find the connections between them and spectral reflection. This would allow choosing proper satellite images, the number and time of over ground observations. Keywords: remote sensing, satellite image, numerical map, GIS, land use.
Article received 2001 06, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) DYKE PROTECTION AND RECONSTRUCTION MEASURES FOR THE AREAS SUFFERING FROM CAVE RODENTSArvydas Povilas MALIŠAUSKAS, Lithuanian Institute for Water ManagementSummaryAbout one fourth of the polder dykes is affected by beavers and musk-rats, which have about 20...50 caves within the length of 1 km. The pit length, which is a result of cave-rodents is up to 10 m, the depth of it varies up to I m. When reconstructing the dykes, priority should be given to the environmental measures. Cave pits in the dykes of 1,5...2 m high it would be more rational to cover them annually with local. soil. The dykes to be reconstructed, which are higher than 2 m are to be strengthened by wire nets, which could be located and poured with soil in a trench that is excavated slope lengthwise. Keywords: dyke, beaver, cave, protection measure, barrier.
Article received 2001 05, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE DEPENDENCE OF PROFIT ON SOIL PRODUCTIVITY IN THE FARMS OF ALYTUS REGIONDaiva MATONIENĖ, Lithuanian University of AgricultureSummaryPotential productivity of light soils in the farms of Alytus region has been analyzed in the article. It has been calculated according to the program (1997) made by professor A. Svedas from Lithuanian Agricultural Institute. The data of soil investigations of analyzed farms have been analyzed. According to this data productivity dependence of agricultural plants (winter rye, barley, oat and potatoes) on soil characteristics has been calculated as well. Real productivity of agricultural plants from 109 farms has been analyzed. Having carried out specified calculations according to the calculation of expenses of agricultural plants (made by the center of labor economics), the fertility of agricultural plants has been defined, according to which one could get a profit in the lands of low productivity. Having fulfilled investigations it has been established, that farmers who manage their farms in sod podzolistic slightly podzolized sandy loam soils are able to reach such fertility of agricultural plants (winter rye, barley, oat), that should ensure profit. The farmers who manage their farms in such soil groups should grow more plants (including state payments) showing a profit or should go in for alternative agricultural activities. The farmers who manage farms in sod podzolistic slightly podzolized sandy loam soils usually reach lower fertility as one could expect according to potential soil fertility. One could successfully manage a farm and get a profit out of it. It is possible to get a profit in sod podzolic slightly podzolized sandy loams. However not everything is being done in the farms in order to reach fertile, ensuring a profit Keywords: land with poor productivity, potential productivity of soil, profit, planting of greenery.
Article received 2001 05, given to print 2001 06. ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) PECULIARITIES OF METHODOLOGY OF EVALUATION FOR THE GROUND TEMPERATURE OF CATTLE - BREEDING BUILDING BASESDainius RAMUKEVIČIUS, Lithuanian university of agricultureSummaryThe article presents experimentally created and tested the base of cattle-breeding building and ground temperature-taking methods of its area. Using given methods it is possible to make more exhaustive ground effect to the cattle-shed temperature regime estimations, on which mostly depend microclimate parameters. Besides, having the Results of ground natural researches we can compare them with analytical calculation or data made by computer program. For ground temperature taking semiconductor transistor is used. A calibration and the temperature transducer resistor dependence upon temperature were made to all transistors like temperature transducer. The method of temperature testing is employed to the natural conditions and is used to establish calibrations curve of each temperature transducer. The Reliability of each curve is characterised by coefficient of determination. Computer worked out test data of some of thermal cattle-shed building base and it's area ground characteristics. Keywords: cattle-shed, ground, temperature, properties, serving, measuring element.
Article received 2001 06, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) ESTIMATION AND DEVELOPMENT OF CALCULATION OF BEAMS USING VARIATIONAL AND NET METHODSKazys SLEZEVICIUS, Jonas ROLICIUS, Siauliai University, Leonas LINDISAS, Lithuanian University of AgricultureSummaryFerroconcrete beams are widely used in hydraulic engineering, precast and industrial construction, in reserviors, bunkers and silos. The beams perform fencing and supporting functions. For calculation - methods of elasticity theory are used. Stresses calculated using one of elasticity theory methods frequently differs from those, worked out using another method. This difference may be considerable, amounting to several times. Stressed state of the beams, calculated using variational and net methods, is analysed in this work. Beams on two supports carry continuous load. The ratio of their height to opening varies within the range of 0.1...10. The values obtained by using the two methods were different. When using the variational method we tried to inerease the number of terms in the polynomial series up to 24, in order to find out what caused the difference between the values. But even in this case the values of stresses did not come closer. Further analysis of the reasons for this disagreement led us to checking if the stress determined by variational method using the series by J. Pratusevičius meets the requirements of biharmonic equation. We found out that this equation was not complied with at the middle point of the beam having any number of terms in the polynomial series. This equation was not complied with at other points of the beam in cases when the number of terms in the polynomal series did not exceed 5. The non-relation of non-compliance of the biharmonic equation increases with the increased of height of the beam. Non-relation was particularly obvious when the ratio of height to width was greater than 1. Thus, variational method, when polynomial was determined by the series of J. Pratusevičius, was not to be applied for beam calculations in cases, when the ratio of height to width was greater than 1. Keywords: beam, ferro-concrete, tentions, variational and net methods.
Article received 2001 02, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) INFLUENCE OF THE NEMUNAS DELTA SEDIMENT DYNAMICS ON THE CURONIAN LAGOON SEDIMENTATIONSaulius VAIKASAS, Lithuanian Institute for Water ManagementSummaryIn the article there are analyzed sedimentation processes in the Curonean Lagoon and Nemunas delta based on comprehensive data of some researchers. High rates of river sediments indicate the intensification process in the Lagoon. It was established that about 80000...2480000 t of sand sediment deposited every year in the Lagoon depending on flood probability extent in the Nemunas river. Only 7-11% of this amount was transported into the Baltic Sea. Therefore, the mouth of the Nemunas river is the greatest source of pollutants with nutrient salts leached from agriculture. As the modelling of the flood activities covering the period of 1950...1991 had been done (based on the "Delta Mathematical model" elaborated by us), it was established that in the grassland area of flooded delta about 37% suspended flood sediments deposited depending on a flood extent. It is possible to reduce the river's load on the Lagoon by means of new sediment and nutrient trap in the flooding Nemunas delta. That is an important subject of investigation in the nearest future. Keywords: Curonean Lagoon, Nemunas delta, sedimentation.
Article received 2001 05, given to print 2001 06 ISSN 1392-2335 Transactions of the Lithuanian University of Agriculture and Lithuanian Institute for Water Management 2001 vol. 15(37) THE ANALYSIS OF ESTIMATION OF ENVIRONMENTAL FLOW METHODS IN FOREIGN COUNTRIES AND IN LITHUANIAGrazina ŽIBIENĖ, Lithuanian University of AgricultureSummaryThe term ,,environmental flow" in Lithuania is equivalent to the terms ,,instream flow", ,,residual flow", ,,minimum flow", ,,minimum acceptable flow", ,,ecologically acceptable flow" which are used in foreign countries. The problems on environmental flow estimation in foreign countries have been investigated for two decades. Almost one hundred methods (empirical and analytical) for the environmental flow estimation have been created. The overview of these methods is presented in the article. Environmental flow of a river in Lithuania is defined as the estimated minimal flow of the river necessary for maintenance of minimal requirements of riverine ecosystem. Up to the end of 1997 minimum flows of all Lithuanian rivers were equated to mean of minimum flows of 30 days in dry period of 95% probability. Since December 1997 the environmental flows have been defined according to the methodology presented in the normative document LAND 22-97. This methodology is based on hydrological characteristics as mean of minimum flows of 30 days in the dry period of 95% or 80% probabilities, factor of natural regulation of run-off. The methodology is presented briefly in this article. Environmental flows of Lithuanian dammed rivers have been established according to the valid methodology and the analysis of these results is presented in the article. Values of environmental flows of Lithuanian rivers, except the biggest Lithuanian river - the Nemunas, are from 6,96 m3/s to 0,001 m3/s and even lower. Environmental flows of 89% of dammed Lithuanian rivers are lower than 0,1 m3/s. The established environmental flows of Lithuanian rivers were compared with values of minimum flows of the same rivers to maintain fish habitat requirements established according to some foreign methods (Tennant, Montana, Tesman, etc.). Comparison of results showed that environmental flows established according to valid methodology in Lithuania in most cases were lower than flows maintaining minimal requirements of fish habitats (estimated according to the mentioned foreign methods). This proves necessity of environmental flows estimation taking into account hydraulic and, especially, hydrobiological characteristics in near future. Following the experience and general tendencies of instream flow determination in Europe the possible ways and stages of methodology for establishment of environmental flow of Lithuanian rivers development are suggested. Keywords: environmental discharge, minimal discharge, hydrology.
Article received 2000 12, given to print 2001 08.
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