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CONTENTS ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 THE IMPROVEMENT OF CALCULATIONS OF SUSPENDED SEDIMENT DEPOSITION IN FLOODED MEADOWS Alfonsas RIMKUS, Saulius VAIKASAS* Summary As the results of our studies carried out in flooded meadows of the Nemunas delta show, suspended sediment deposition in grass-covered areas is much more intensive than in riverbeds with sand deposits on the bottom. The existing mathematical models do not consider that fact and use the equations created for the calculations of sediment deposition in riverbeds. This resulted in insufficient estimation of the effect of flooded meadows on sediment deposition and water purification processes. A suitable method for the calculation of suspended sediment deposition in grass-covered areas needed to be created. On the basis of the measurement data collected in the Nemunas delta, new formulas for the calculation of deposition intensity were created. Previously, those formulas were considered as empirical. The paper presents a new theoretically based calculation method. Keywords: suspended sediments, sedimentation process, hydraulic calculations, flooded meadows.
*contact person Dr. habil. Alfonsas Rimkus, freelance researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – hydraulics of hydrostructures, riverbed processes. Dr. habil. Saulius Vaikasas, senior researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, hydraulic modeling, riverbed processes. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: s.vaikasas@delfi.lt Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 ANALYSIS OF THE DYNAMICS OF FRACTIONAL COMPOSITION OF FLOOD SUSPENDED SEDIMENT IN THE NEMUNAS Saulius VAIKASAS, Romualdas PUKŠTAS Summary The paper gives study results confirming that a significant amount of biogenic pollutants are transported via the Nemunas into the Baltic Sea by suspended sediments composed of small-sized clay particles and organic matter. Specific texture of those particles prevent them from decomposition during the period of transportation, therefore a certain amount of pollutants reach seacoast almost unchanged. When studying the fractional composition of sediments in typical laboratory methods, the particles are fragmented and thus the study results do not show the actual composition of sediments. For the determination of the relation between the amounts of sediments and pollutants, it is more rational to use a fractionmeter of infrared radiation created at our institute. An average relationship between nitrates and concentrations of clay particles contained in the Nemunas flood water was determined. The measured dynamics of the changes in grain-size composition was applied for the creation of the mathematical model. Keywords: sediments, fractional composition, biogenic pollutants.
*contact person Dr. habil. Saulius Vaikasas, senior researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, hydraulic modeling, riverbed processes. Address: parko 6, Vilainiai LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 68109. E-mail: s.vaikasas@delfi.lt. Dr. Romualdas Pukštas, senior researcher, Polder laboratory, Water Management Institute of Lithuanian University of Agriculture. Researc interests – ground physics, measurement devices. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 The modeling of regional financing of land reclamation works Valentinas ŠAULYS*, Nijolė BASTIENĖ Summary As the regulations of the program of agricultural and rural development strategy within the period of 2000–2006 specify, along with the changes in land reclamation infrastructure it is necessary to create the means ensuring rational regional agricultural specialization corresponding to natural conditions. Before the new law dealing with land reclamation was confirmed, the funds for the maintenance of all land reclamation equipment were allocated from the state budget. The changes in the value of state-owned land reclamation equipment would also determine certain changes in the financing of land reclamation works. First of all, the financing of land reclamation works should be based on economic criteria. After the restoration of land ownership rights the intensity of land usage has also changed. In Lithuania, in the territories less favorable for farming with drained land areas the land plots are not used intensively enough for agricultural activities due to low land productivity points. There are places where drainage systems are totally worn out. The reconstruction of such drainage systems would require large expenses, however the investment in similar objects is often vague and doubtful. There is really much risk to invest in such kind of objects. On the basis of the analysis results of the situation, the article gives four scenarios of possible allocation of special state subsidies for municipal budgets to be given to land reclamation works. Those scenarios estimate farming land in different districts, evaluate derelict land areas as well as consider regional differences in the income of agricultural subjects that depends on increased land productivity points. When modeling the financing results of land areas in districts based on the regional distribution methodology of state funds, the changes in base financing indices are under discussion. When applying the methodology suggested, in the Middle Lithuania region where the draining activity is of great importance the base financing index would increase up to 1.39. Meanwhile, in Eastern Lithuania and regions of Lower Lithuania where the draining activity is less important, the base financing would be reduced by 35%. In regions with average draining importance the financing of draining activities is minimal and base financing index is changing only by ± 3%. Keywords: land reclamation equipment, regional financing, modeling.
*contact person Dr. assoc. prof. Valentinas Šaulys, senior researcher, Head of Exploitation Laboratory, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, investigation of the usage and maintenance of land reclamation equipment. Address: Parko 6, Vilainiai, LT-58102 Kėdainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: valentinas@water.omnitel.net . Dr. Nijole Bastienė, senior researcher, Exploitation Laboratory, Water Management Institute of the Lithuanian University of Agriculture. Research interests – environmental engineering and landscape management, researches of drainage system reliability and exploitation efficiency. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 SUCCESSION OF AGROCHEMICAL PROPERTIES AND MICROORGANISMS IN SANDY LOAM CAMBISOLS FERTILIZED WITH SAPROPEL OF DIFFERENT CHEMICAL COMPOSITION Eugenija BakšienĖ*, Jūratė REPEČKIENĖ, Olga SALINA Summary In 1994–1999 in the Vokė Branch of the Lithuanian Institute of Agriculture the research on agrochemical properties and microorganism changes in crop rotation on sandy loam Cambisols fertilized with calcareous, organic, siliceous sapropel and its mixtures with other organic fertilizers (manure, sewage) was carried out. Summarized results of a long-term experiment on sandy loamy Cambisols have shown that calcareous sapropel and its mixture with manure reduced the acidity of soil. Organic and silicon sapropel had no effect on those indices. Organic and silicon sapropel increased the amount of total nitrogen and humus contained in soil. The amount of mobile phosphorus and potassium has decreased. It was revealed that sapropel of different chemical composition predetermined the distribution of certain groups of microorganisms. Micromycetes were mostly isolated from the soil fertilized with organic and siliceous sapropel, bacteria was isolated from the soil fertilized with organic sapropel, and most streptomycetes were isolated from the soil fertilized with calcareous sapropel. In soil fertilized with calcareous sapropel the abundance of micromycetes rarely equaled to the amount of micromycetes determined in control plots fertilized only with manure. Calcareous and organic sapropel increased the abundance of streptomycetes in soil. In soil fertilized with siliceous sapropel their amount was lower than in soil where manure was applied. Keywords: sapropel, manure, soil, properties, micromycetes, streptomycetes.
*contact person Eugenija Bakšienė, deputy director, Vokė Branch of LIA. Research interests – agronomy, agrochemistry. Address: Žalioji a. 2, Trakų Vokė, LT-02232 Vilnius, Lithuania. Phone: +370 5 2 64 54 30. E-mail: eugenija.baksiene@voke.lzi.li . Jūratė Repečkienė, senior researcher, Institute of Botany. Research interests – microbiology, micology. Olga Salina, senior researcher, Institute of Botany. Research interests – microbiology, micology. Received 11 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 INVESTIGATION ON DRAINAGE RUN-OFF AND DIN (DISSOLVED INORGANIC NITROGEN) LEACHING IN FIELDS OF EARLY AND LATE CULTIVATION Kazimieras GAIGALIS*, Ginutis KUTRA, Giedrius BAIGYS Summary The effect of field cultivation time on DIN leaching has been studied out in field tests carried out in 0.76–1.36-ha fields. The study object was arranged in Pikeliai village (Kėdainiai district). Soils prevailing in the study object are calcareous gley brown soil (RDg-4-K2), sandy light loam and sandy loam on deeper layers of sandy loam and sandy light loam. The arable horizon contains sandy light loam, which is characteristic to soils prevailing in the Middle Lithuanian Plain. Having summarized the study results of drainage runoff that ultimately affects nitrogen leaching, it was determined that the impact of land cultivation time on the runoff coefficient was more significant under the conditions of runoff formation during the snow thaw period in winter. In winter of 2002, the runoff coefficient was 1.09 in the field of early cultivation and 0.53 in the field cultivated late in autumn. Land cultivation time also affected DIN content in the soil. Before the freezing period in 2003, DIN content in the variant of late cultivation was 26.9 kgN/ha less than in the variant of early cultivation. In variant with intermediate crops late cultivation determined 22.9 kgN/ha and 33 kgN/ha less DIN amount in 2001 and 2002 respectively; however in 2003, the difference in DIN content was only 1.8 kgN/ha due to cultivation time, i.e. it was less significant than in the variant that contained no intermediate crops and was cultivated late in autumn. Keywords: land tillage, drainage run-off, nitrogen concentration, nitrogen leaching.
*contact person Dr. Kazimieras Gaigalis, head of Water Resources Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – hydrology, water flow and quality monitoring. Address: Mituvos 9, Kaunas LT-3009, Lithuania. Phone/fax: + 370 37 33 12 70. E-mail: gaigalis@water.omnitel.net . Dr. Ginutis Kutra, senior researcher, Water Management Institute of Lithuanian University of Agriculture. Research interests – water protection, sustainable use of nutrients. Giedrius Baigys, engineer, Water Management Institute of Lithuanian University of Agriculture. Research interests – water protection, non-point source pollution. Received 12 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 IMPACT OF CLIMATIC, HYDROLOGICAL AND HYDROCHEMICAL FACTORS ON BENTHOS OF THE STREAM GRAISUPIS Kęstutis ARBAČIAUSKAS, Kazimieras GAIGALIS*, Aušra ŠMITIENĖ, Giedrė VIŠINSKIENĖ Summary The paper analyses benthos parameters, climatic factors, stream water discharge, and nitrogen and phosphorus concentrations in water of the stream Graisupis in 1998–2003. It was determined that the ecological status of the monitoring stream became worse according to the benthos parameters during the studied period. The number of taxa sensitive to pollution (stoneflies, mayflies and caddisflies), the mean Chandler biotic index and benthos biomass decreased. This happened under the conditions of increased air temperature, reduced rainfall and stream water discharge, increased phosphorus concentration, reduced nitrogen concentration and reduced N/P ratio. The analysis has shown that the deterioration of the stream Graisupis ecological status was determined by the reduction of rainfall during summer time, which caused longer periods of stagnant stream water or small water discharge , and deteriorated oxygen conditions due to organic matter destruction in the stagnant water. Deterioration of the conditions could be indirectly indicated also by the reduced N/P ratio. The conclusion was drawn that climatic factors and possible global environmental change have to be considered when agricultural pollution impact on monitored stream ecological status is to be evaluated. Keywords: stream, benthos, rainfall, water flow, phosphorus, nitrogen.
*contact person Dr. Kestutis Arbačiauskas, senior researcher, Ecological Institute of Vilnius University. Research interests – water ecology. Dr. Kazimieras Gaigalis, the head of Water Resources Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – hydrology, water flow and quality monitoring. Address: Mituvos 9, LT50134 Kaunas, Lithuania. Phone/fax: + 37037 331270. E-mail: gaigalis@water.omnitel.net . Aušra Šmitienė, Ph. D. student, Water Management Institute of Lithuanian University of Agriculture. Research interests – water quality modelling in small agricultural watersheds. Giedrė Višinskienė, junior researcher, Ecological Institute of Vilnius University. Research interests – trichopteran and stream benthos ecology. Received 12 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 ANALYSIS OF THE CHANGES OF WATER DISCHARGE AND NITROGEN CONCENTRATION IN AGRICULTURE-AFFECTED RIVERS Kazimieras GAIGALIS*, Ausra ŠMITIENE Summary Water quality investigations of agriculture-affected rivers in Lithuania are performed at two levels: 1) according to the national monitoring programme in upper reaches of rivers where runoff originates mainly in agricultural areas and other bigger pollution sources are absent; 2) in small streams where complex investigations are performed by the Water Management Institute of LUA. In this work the rivers Akmena (at Tubausiai), Lėvuo (upstream Pasvalys), Minija (upstream Plungė), Nevėžis (upstream Panevėžys), Šyša (upstream Šilutė), Šušvė, Šventoji (upstream Anykščiai) and Tatula (upstream Biržai) and the small streams Graisupis, Lyžena tributary L-1 and Vardas affected by agricultural activity are compared. As the analysis of monitoring results of the period 1996–2002 has shown, specific water runoff of the rivers of the Middle Lithuania are smaller and nitrate nitrogen concentrations are higher than those of the rivers of the Western Lithuania. Mean nitrate nitrogen concentration in the agriculture-affected streams (Graisupis, Lyžena tributary L-1 and Vardas) are up to 3 times higher than in the larger rivers affected by agriculture in the same region. The investigated 8 rivers have been divided into two groups according to the changes in water discharge and nitrogen concentration, where more similarities among the rivers of the Middle Lithuania have been distinguished, compared th the rivers of the Western Lithuania. The best water discharge correlation of the agriculture-affected streams was determined between the stream Graisupis and larger rivers of the same region. Nitrate nitrogen correlation between Graisupis, Lyžena tributary L-1, Vardas and larger rivers was small; this might have happened because water quality of small streams fluctuates more intensively showing the impact of individual factors in the watershed. Keywords: agriculture-affected rivers, water discharge, nitrogen.
*contact person Dr. Kazimieras Gaigalis, the head of Water Resources Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – hydrology, water flow and quality monitoring. Address: Mituvos 9, LT-50134 Kaunas, Lithuania. Phone/fax: + 370 37 33 12 70. E-mail: gaigalis@water.omnitel.net . Aušra Šmitienė, Ph. D. student, Water Management Institute of Lithuanian University of Agriculture. Research interests – water quality modelling in small agricultural watersheds. Received 12 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 INVESTIGATION AND ASSESSMENT OF THE STATE OF PROTECTIVE BELTS AND INFLOW OF EROSION PRODUCTS INTO THE DRAINAGE CHANNELS Stasys Ragauskas Summary As the results of the studies on the condition of protective belts have shown, due to improperly managed and mechanically damaged trenches large amounts of erosion products contained in surface water inflows the channel. Disorderly trenches neither correspond to the design parameters nor meet the environment protection requirements; their mechanical damages are related to improper human activity in the adjacent zone of trenches. According to principles of the type of soil appearance in the channel bed, four groups of damages might be distinguished: soil entrance into the trench during the tillage of trenches; inflow of erosion products from the basin; scours of trench slopes and washout of turf flumes for surface water discharge. The most frequent damages enhancing the washout of flumes and inflow of erosion products are total or partial tillage of trench slopes. From the point of view of erosion process, the inflow of erosion products from the basin and siltation of trenches are considered as the most dangerous damages. Keywords: protective belt, erosion products, inflow from basin, washout of flumes, siltation of trench.
Stasys Ragauskas, junior researcher, Exploitation Laboratory, Water Management Institute of Lithuanian University of Agriculture. Research interests – exploitation and maintenance of drainage channels. Address: Parko 6, LT-58102 Vilainiai, Kėdainiai district, Lithuania. Phone: +370 347 6 81 09. E-mail: valentinas@water.omnitel.net . Received 12 2004.
ISSN 1648-4363 Transactions of Lithuanian University of Agriculture and Water Management Institute of Lithuanian University of Agriculture, 27(47), 2004 INVESTIGATION OF THE LEGAL FRAMEWORK AND ENVIRONMENTAL REQUIREMENTS FOR THE DEVELOPMENT OF HYDROPOWER IN LITHUANIA Petras PUNYS*, Kazys Sivickis Summary This paper analyses the national, EU and international legislation, conventions related to the development of renewed energy sources, hydropower in particular, river engineering issues in connection with river environment, protection of living and physical nature. The legal framework of hydropower and dam construction is favourable for their development; the projects are not discriminated according to their scales. However, when developing water projects or exploiting them, the principles of sustainable development must be taken into account. The review and comparison of Lithuanian legal framework regarding river engineering with those of the other countries reveals that the legislation is strictest in the expanded EU. All large and almost all mid-sized rivers exempted from damming at national level can be regarded as an unprecedent case in Europe. Accordingly, hydropower and related water uses like navigation, irrigation, fishery, and water supply, flood protection, low flow maintenance, heritage promotion are to be restricted. The contradiction between environmental protection and promotion of renewed objects might be observed in the EU legislation. The same goals are set: to protect water bodies and avoid emissions to the atmosphere. There is the need to review the environmental legislation in force dealing with river engineering in order to combine 3 main priorities: economic policy, social policy and environment protection. The evaluation of the quantitative impact of national environmental legal framework on hydropower resources is given in the paper. This impact is compared to that prevailing in other EU countries. The current available hydropower potential of small and mid-sized rivers (approx. 5% of natural potential which is the lowest in Europe) is hardly to fulfill the EU indicative targets for the promotion of the use of renewed objects for electricity production by the year 2010. After exploitation of the above-indicated percentage, no further prospects exist for hydropower, taking into consideration the strict environmental policy with regard to river protection. The reference period of this study is 2001–2003, during which environmental legislation regulating national hydropower sector and river engineering measures were promulgated. Keywords: legal acts of hydro-energetics and environment protection.
*contact person Dr. Petras Punys, acting professor, head of Water Management Department, Lithuanian University of Agriculture. Research interests – hydrology, hydro-energetics, management of water resources. Address: Universiteto 10, LT-53361 Kaunas–Akademija, Lithuania. Phone: +370 37 39 73 37. E-mail: punys@eko.lzua.lt Dr. Kazys Sivickis, acting associate professor, Water Management Department, Lithuanian University of Agriculture. Research interests – hydro-energetics, technologies of hydraulic engineering constructions, administration and management of enterprises. Received 12 2004.
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