Contents

Karst is a special type of landscape that is formed due to the dissolution of Devonian sulphate and calcareous rocks, including gypsum, limestone and dolomite in the northern part of Lithuania. Upper parts of aquifers represented by Devonian water bearing sediments have a direct link to surface streams of the area. The discharge of mineralized groundwater into surface streams significantly affects their chemical composition. Therefore, the streamwaters in the karst region contain increased quantities of dissolved major constituents (Ca, Mg, Na, K, Cl, Si, SO4 and HCO3).

In this paper the data on major dissolved constituents from 5 karst-affected Lithuanian rivers at 10 sampling sites during the period from 1991 to 2001 were analyzed. The results have indicated that the concentrations of the constituents vary considerably from site to site due to variability of natural (karst-affected) and anthropogenic inputs. During the study period sulphate and calcium concentrations in the streams were changing from 20 to 592 mg/l and from 15 to 400 mg/l respectively, total hardness and TDS varied from 2 to 19 meq/l and from 100 to 1000 mg/l accordingly. The quantities of major constituents in karst-affected streams were found to be up to 12 times higher as those in non-affected ones.

The significance of changes of each variable between two sampling points (null hypothesis) was tested by ANOVA. The similarity (or dissimilarity) of concentrations among sampling sites was evaluated by cluster analysis which showed that lower and middle reaches of the Tatula and the Levuo rivers contribute most significantly to the input of sulphate and calcium in streamwater.

Keywords: karst, major dissolved constituents, streamwater.

• Dr. Arvydas Povilaitis, associate professor of Land Reclamation & Improvement Department, Lithuanian University of Agriculture.

  • Research interests – hydrology, water quality, mathematical modelling and GIS.

  • Address: University st. 10, LT-4324 Kaunas-Akademija, Lithuania. Tel. +370 37 75 23 80. E-mail: arvis@hidro.lzuu.lt .

Article received 04 2003, given to print 05 2003.

The investigations on chemical and microbiological pollution of water in dug wells were carried out in Pypliai settlement (Kaunas district). The objective of the study was to estimate seasonal changes in water pollution. During the study period two groups of wells were distinguished: the wells with average nitrate concentration no higher than the permissible level (group 1) and the wells with average nitrate concentration exceeding the permissible level (group 2).

The wells with nitrate concentration no higher than the permissible level experience insignificant change in water quality per year (in absolute values): the average nitrate concentration fluctuates from 6 mg l-1 in autumn to 34 mg l-1 in spring in those wells. The wells with nitrate concentration higher than the permissible level experience a much more significant changes in water quality. Here the average nitrate concentration fluctuates from 52 to 150 mg l-1. The significant interval of average concentration is also larger in water of polluted wells, particularly in spring and summer. Water pollution fluctuation interval is larger in those wells.

The tendencies of the pollution of dug wells with organic matter and nitrates are similar. Permanganate content is higher in wells of group 2 than in wells of group 1. This implies that larger amount of organic pollutants is contained in wells with nitrate concentration higher than the permissible level. Hydrogen ion concentration was changing insignificantly within a year – from 6.5 to 8.2 pH; however the fluctuation characteristics in both groups were similar to the changes in nitrate and organic matter concentrations. Color degree is also higher in wells with nitrate concentration exceeding the permissible level. The lowest load of esherichija coli bacteria, as well as coliform bacteria, is observed in spring. In other seasons of the year esherichija coli bacteria load is higher, while changes between loads of the two types of bacteria are insignificant.

As the study results show, the wells with higher nitrate pollution concentration are more polluted according to all indices. On the contrary, the wells with lower nitrate pollution concentration are less polluted. Moreover, the changes in water quality of dug wells are seasonal. More significant water pollution is observed in a warm period of the year; in cold periods of the year water pollution in wells is less significant. The highest nitrate concentrations in water of dug wells are observed in spring, the highest loads of organic matter and ammonia ions are observed in summer. Water color degree is highest in a warm period of the year, while in cold periods water color is less intensive.

Keywords: shaft-type wells, water quality, nitrates, ammonia, acidity, microbiological load.

• Dr. Vida Rutkoviene, docent, director of the Institute of Environment, Lithuanian University of Agriculture.

  • Research interests – ecology and environmental studies, environmental engineering.

  • Address: Studentu 11, Akademija, LT-4324 Kaunas district, Lithuania. Phone: +370 37 75 22 02. E-mail: ai@nora.lzua.lt .

• Dr. habil. prof. Albinas Kusta, rector of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management.

  • Address: Studentu 11, Akademija, LT-4324 Kaunas district, Lithuania. Phone: +370 37 32 32 05. E-mail: KUSTA@nora.lzua.lt .

• Dr. Saulius Kutra, lecturer at Ecology department, Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, GIS, pollution modeling, application of remote sensing.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 82 47. E-mail: kutra@water.omnitel.net .

• Laima Cesoniene, doctorate student at Ecology department, Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape, control of environment pollution.

  • Address: Studentu 11, Akademija, LT-4324 Kaunas district, Lithuania. Phone: +370 37 32 32 05. E-mail: ek@nora.lzua.lt .

Article received 04 2003, given to print 05 2003.

Precipitation fluctuations at measurement points are determined by a variation coefficient. For monthly precipitation this coefficient changes within a range of 13 to 119% (Pakruojis, may). Since every single precipitation measurement point is situated at a different distance from the basin, applying Thiessen method the basin was divided into appropriate test grounds. As the division of the basin shows, the largest area of the basin is characterized by two main points: Dotnuva and Radviliskis. Smaller parts of the basin are under the influence of Siauliai, Kelme, Raseiniai and Vilainiai. Further situated Pakruojis, Panevezys, Jonava and Kaunas have no major impact on precipitation distribution in the Susve basin. The modelling for the estimation of precipitation amount in the basin was done by generating random figures, considering average measured precipitation amounts and their variation. Precipitation was generated for six points the data of which may be applied for the basin as well. Generated calculation results were compared to measured precipitation amounts. As the comparison has shown, generated precipitation is similar in its nature to the one measured during the last decade (1992-2002). Modelled precipitation of the Susve basin is of stochastic nature and might be generated on the basis of precipitation variation characteristics considering the data collected at the measurement points.

Keywords: precipitation, precipitation variation, precipitation model, basin Susve.

• Dr. Saulius Kutra, head of Modelling and informatics laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, GIS, pollution modeling, application of remote sensing.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 82 47. E-mail kutra@water.omnitel.net .

• Dr. Laima Berankiene, scientific worker of Modelling and informatics laboratory at the Water Management Institute of Lithuanian University of Agriculture

  • Research interests – environmental engineering and landscape management, hydrology, river pollution.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. E-mail berankiene@freemail.lt .

Article received 04 2003, given to print 05 2003.

Complexes of river-channels morphological derivatives (such as macro-scale configuration which in common case expresses external view of the river- channel) best reflect the total amount of river bed processes. As a rule, river- channels are classified into certain types. Primary classification is simple – river-channels are classified into straight, meandering and branched out river channels. It is observed that in variuos river-channel types river bed processes, i. e. deformations of river-channels which are under influence of basic river-channels forming factors, come out according to undoubtedly different regularities. Obviuosly, in a straight and highly meandering river different deformations with respect to the time, location in a plan, and size take place. Therefore, with scientific and engineering aims river-channels classification has been constantly improved. Furthermore, theory of river-channels classification is being developed at present as well.

The purpose of this paper is to suggest a new method of river-channels classification according to the criterion of channels constancy/ Grisanin criteria researches, and to motivate the scientific and practical application of this new method. The article reviews the development of river-channels classification. There is a description of the investigation of this point. The importance of river-channels classification to the investigation of subsequent theoretical river bed processes and objects of hydraulic engineering is emphasized.

According to the criterion of river-channel constancy investigations, river-channels in Lithuania are suggested to be classified into straight channels with alternating bars, adapted type and highly meandering channels. It has been proved that the most important parameters of different types of river-channels, such as middle depth, width and discharge, are interdependent according to the regularities characteristic to the above-mentiond types of river-channels. The constancy and trend of deformations of a river channel can be evaluated on the basis of the type of a river-channel.

Keywords: river, channel type, criteria of constancy.

Article received 04 2003, given to print 05 2003.

The paper presents the results of comparative investigations on nitrogen compounds concentrations and outflow in different types of grasslands. The investigations were carried out in 10-15-year old agricultural meadows arranged in drained alluvial bog soil in the period of 1996-2002.

Soil bulk density of the surface layer in unmown meadows decreased on the average by 2-10% in a 4-year period to compare with the hayfield. The mineralisation process of organic mass of unmown grass resulted in 60% higher nitrate-N content in the soil. Unmown meadows experienced more intensive leaching of nitrate-N, total N and P amounts. Thus the increasing number of unmown meadows in drained lands might cause a heavier background pollution of surface water with nitrates.

Keywords: grassland, drainage runoff, nitrogen, phosphorus, potassium, concentration, leaching.

• Dr. Arvydas Povilas Malisauskas, senior scientific worker, the head of Polder Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, hydraulic engineering, hydrology of small watersheds.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Tel. +370 347 6 80 09. E-mail: a.malisauskas@water.omnitel.net .

• Giedrius Adomaitis, junior scientific worker of Polder Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – environmental engineering and landscape management, agrochemistry.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Tel. +370 347 6 80 09.

Article received 04 2003, given to print 05 2003.

Natural conditions in the Middle Lithuania are most suitable for agriculture and farm creation or development. These conditions influence not only the number and size of farms, but also the volume of land reform activities. This zone covers 37,3 % of country’s territory and includes 40,8 % of all agricultural land. Another reason for more active land reform in this zone is farmers’ intention. Farmers yielding much from land become more active and wish to restitute or privatize land as quickly as possible. The small area of unused state land also shows intensive formation and development of private farms.

The tendency to rent agricultural land rather than sell is illustrated while analyzing land market in the Middle Lithuania districts. The factors which influence expansion of farms are analyzed in the article. The analysis of land use showed possible land area for private farms expansion.

Keywords: Middle Lithuania zone, use of agricultural land, land market, farms expansion.

• Dr. Audrius Aleknavicius, lecturer of Land Management Department at the Lithuanian University of Agriculture.

  • Research interests – real estate market, land management, expansion of private tenures.

  • Address: Universiteto 10, LT-4324 Kaunas-Akademija, Lithuania. Phone: +370 37 39 77 32, fax: +370 37 39 74 92. E-mail: alek@info.lzua.lt .

Article received 04 2003, given to print 05 2003.

The study results enable us to estimate the relations between slurry application periods and phosphorus leaching under the conditions of intensive farming. When sugar beet was grown, phosphorus input into the soil with mineral fertilizers was 33.1 kg/ha; when barley and spring rape were cultivated, phosphorus inputs with mineral fertilizers were 16.5 and 14.5 kg/ha respectively. The most intensive phosphorus removal is via plant uptake: during the first study year P-removal through the process of plant uptake was 22.0 kg/ha; during the second, the third and the fourth study years P-removal via plant uptake was 14.3, 13.6 and 21.4 kg/ha respectively. As the study results show, P-leaching is mainly predetermined by precipitation (r = 0.58), fertilization (variant I r = 0.68; variant II r = 0.96; variant III r = 0.94) and also by total input of phosphorus into the soil of the test field (variant I r = 0.56; variant II r = 0.86; variant III r = 0.54).

The most intensive P-leaching through drains is observed in the variant where slurry is applied in autumn (on the average 0.31 kg/ha). When applying slurry in spring, 28.6% less amounts of phosphorus are leached through drains. When slurry is applied in autumn and in spring (half of rate in each of the seasons), leached phosphorus amounts are 20% smaller compared with those leached from the variant where slurry is applied in autumn. Therefore, to reduce phosphorus leaching, slurry needs to be applied in spring.

No influence of draining intensity on phosphorus leaching was observed: the same amounts of phosphorus were leached in test fields of both types – average 0.07 kg/ha.

Total P balance was positive during the first and the second study years. Long-lasting dry periods impeded the complete uptake of phosphorus and hampered to obtained planned yields of cultivated plants. No slurry was applied in clover fields therefore here P balance was negative. Negative P balance was also observed in the field of spring rape where slurry was applied in autumn. This was because large amounts of phosphorus were needed for vegetative mass of plants to grow.

Keywords: crop rotation, slurry, phosphorus leaching, phosphorus balance, environment.

• Dr. Simanas Askinis, senior scientific worker of Water Treatment Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – ecology and environmental studies, handling of wastewater and manure and the effect of the process on the environment, investigations on pollutants transformation processes.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone +370 347 6 80 20. E-mail: s.askinis@delfi.lt .

• Dr. Stefanija Miseviciene, scientific worker of Water Treatment Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – ecology and environmental studies, handling of manure and the effect of the process on the environment, investigations on pollutants transformation processes.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone +370 347 6 80 21. E-mail: kestmis@takas.lt .

Article received 04 2003, given to print 05 2003.

Delta of the river Nemunas covers an area from the outlet of the tributary Jura to the Curonian Lagoon in Klaipeda District. In fact, every year an area up to 52,4 thousand hectares is inundated during the spring floods. The destructive flood consequences adversely affect life, farming conditions and property of 3,2 thousand inhabitants of Rusne and Panemune and other 46 villages.

The main purpose of this paper was to find out what statistical methods can be used to analyse floods as extreme events and to calculate probabilities of exceedance of the highest recorded water level. Also a regression model was made up to predict flooding area, which was based on the highest water levels in measuring points of Tilze and Smalininkai.

Keywords: floods, probabilities, factors, regression model.

• Dr. Valerija Karpickaite, lecturer at the Kaunas University of Technology.

  • Research interests – mathematics, informatics, physical science.

  • Address: Studentu 50, LT-3031 Kaunas, Lithuania. Phone: +370 37 45 16 58.

• Julija Smirnova, master student at the Kaunas Technological University.

  • Research interests – mathematics, extreme events.

  • Address: Studentu 50, LT-3031 Kaunas, Lithuania. E-mail: julija.sm@one.lt.

Article received 04 2003, given to print 05 2003.

The changes observed in the European Union are effectively adapted to our country’s agriculture. The strategy of agricultural development in separate regions of the country should be chosen in order to use agricultural funds from the European Union support program in the most effective ways taking national interests into consideration. This question is especially urgent in the areas less favourable for farming, where the income received from agricultural activities is insufficient to defray expenses.

In 1998-2000, having collected the data of farmers questionnaire poll, a close interrelation between the fertility of agricultural plants and the productivity of farming lands in Alytus district was established. The yields of winter wheat, winter rye, triticale, spring barley, buckwheat, potatoes, spring wheat and perennial grass depended on the productivity points of farming lands.

Keywords: agricultural plants, fertility, farming land productivity.

Annual amounts of wastes have a tendency to increase. With the implementation of National waste utilization program, each district of the country implements different regional waste handling programs as well as prepares normative documents and regulations. The paper presents the analysis of municipal wastes handling methods. Considering the analysis results, the methods are evaluated from economical and environmental points of view, referring to the use of non-traditional energy resources. The investigation on the formation, accumulation and handling process of wastes in Kedainiai district has been carried out, wastes handling strategy and activity program have been presented on the basis of the study results.

To estimate the ecological condition of landfill environment, the investigations on leachate and accumulated pollutants in three representative landfills of different age were carried out. This allowed us to predict pollution dynamics and extent as well as to suggest some less expensive means and methods for pollution reduction and improvement of ecological condition of landfill environment.

Keywords: wastes, landfills, leachate, effect on the environment.

• Dr. Albertas Steponavicius, scientific worker of Water Treatment Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – impact of manure handling on the environment, investigations on wastewater treatment process and landfill leachate.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 20.

• Dr. Zenonas Strusevicius, senior scientific worker, head of Water Treatment Laboratory at the Water Management Institute of Lithuanian University of Agriculture.

  • Research interests – ecology and environmental studies, impact of wastewater and manure handling and usage on the environment, investigations on pollutants transformation processes.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Phone: +370 347 6 80 20. E-mail: zenonas@water.omnitel.net .

Article recived 04 2003, given to print 05 2003.

The quantity of water losses is an important indicator of positive or negative evaluation of water distribution system efficiency. Therefore any water company has great interest in reduction of water losses, because this is mainly related to the reduction of expenses. Although in theory water losses may be eliminated, in practice it is hardly possible, as a leak-free network is neither achievable technically nor it is feasible economically. Most experts adhere to the opinion that it is not feasible to strive for the reduction of the water loss below 8-12% of water supplied to the network, as the investments in operation and rehabilitation and the cost of extremely thorough maintenance of the network surpass the value of the water saved. Currently, average water loss in water distribution systems of Lithuanian towns varies from 15 to 40%.

The information on Plunge water distribution network valves, hydrants and other network fixtures, their condition and maintenance processes, the data on water users, volume of water supplied and sold, and trends of respective change were collected and analysed during the project. All the available information concerning water loss in the water-supply system, starting from extraction points at well-fields to the consumers’ taps, was collected and analysed.

Taking into account the physical reasons of differences between supplied and sold water volumes the losses were subdivided into two types – real and virtual. Each of the items was investigated separately, and qualitative and quantitative results of each item are presented in the paper. Influence of water losses on the cost price of water has been determined. Based on the analysis of present situation, possible measures for the reduction of water losses in the distribution system are presented.

Keywords: water losses, water supply network, reduction of losses, water meters in flats.

• Dr. Vilius Sulga, associate professor of the Water Management Department at the Vilnius Gediminas Technical University.

  • Research interests – water treatment technology and industrial wastewater treatment.

  • Address: Sauletekio ave. 11, LT-2040 Vilnius, Lithuania. Phone +370 5 274 47 13. E-mail: vk@ap.vtu.lt .

• Dr. Algirdas Bronislovas Matuzevicius, professor, head of the Water Management Department at the Vilnius Gediminas Technical University.

  • Research interests – biological wastewater treatment, phosphorus and nitrogen removal, sludge treatment.

  • Address: Sauletekio ave. 11, LT-2040 Vilnius, Lithuania. Phone: +370 5 274 47 13. E-mail: vk@ap.vtu.lt .

• Dr. Mindaugas Rimeika, associate professor of the Water Management Department at the Vilnius Gediminas Technical University.

  • Research interests – stormwater management, water and wastewater networks.

  • Address: Sauletekio ave. 11, LT-2040 Vilnius, Lithuania. Phone: +370 5 274 47 13. E-mail: mindaugas.rimeika@ap.vtu.lt .

Article received 04 2003, given to print 05 2003.

While developing agricultural production in the country, most attention is paid to the agricultural policy of the European Union (the EU). The changes observed in the development of agriculture are effectively adapted into our the country’s agriculture. The strategy of agricultural development in separate regions of the country should be chosen in order to use agricultural funds from the EU support program in the most effective way, taking national interests into consideration.

The area less favorable for farming is one of agricultural regions. In such area the farming activity depends on many specific factors, such as low crop yields, unfavorable demographic situation, lower professional qualifications of farmers, lack of primary investments for farm development, weak social and technical infrastructure, prevailing small and mid-size farms.

No economically and practically grounded solutions concerning land use can be taken because of the lack of exact data on agricultural subjects. Therefore, the research on the land plots situated in the territory less favorable for farming is necessary. This article deals with the analysis of size and farming type of private farms in Alytus region.

Keywords: land areas less favorable for farming, farm size, farm type.

• Dr. Daiva Matoniene, lecturer at the Land management department, Lithuanian University of Agriculture.
  • Research interests – land planning in areas less favorable for farming.
  • Address: Universiteto 10, LT-4324 Kaunas-Akademija, Lithuania. Tel. +370 37 39 77 32. E-mail: dmaton@infos.lzuu.lt .

Article received 04 2003, given to print 05 2003.

The paper discusses the change of longitudinal acoustic wave into the transverse one and the dependence of this process on soil moisture. The investigations were carried out in light clay soils. The paper includes the description of study equipment and methodology; it also presents the relationship between the propagation of transverse acoustic waves in cohesive ground and the porosity of the ground. The analysis of the dependence of transformation process of acoustic impulse on the soil moisture is presented as well.

Keywords: ground, sound speed, moisture, porosity.

• Dr. Romualdas Pukstas, senior scientific worker of the Polder laboratory at the Institute for Water Management of Lithuanian University of Agriculture.

  • Research interests – ground physics, measurement devices.

  • Address: Parko 6, Vilainiai, LT-5048 Kedainiai district, Lithuania. Tel. +370 347 6 80 09.

Article received 04 2003, given to print 05 2003.

During the land reform in Lithuania the establishment of farms has been performed since 1989 following laws and other juridical acts. However, there are no scientific researches that might help to analyze economical and ecological background of agricultural territories.

The efficiency of land use depends on compatibility of favorable natural and economical conditions of a locality. The aim of the work is to analyze present situation, to determine and evaluate possibilities for the expansion of farming land tenures at the same time creating conditions for the efficient functioning of production and rational land use, to ground the efficiency of solutions and ecological impact with the help of particular calculations.

The paper presents the analysis of the users of agricultural land, their land tenures, and amounts of agricultural production while differentiating farms according to their size and farming activity. For the analysis of the period 2000-2002 the following districts have been chosen: Sateikiai, Plateliai and Paukstakiai subdistricts of Plunge district, Domeikava, Garliava and Vandziogala subdistricts of Kaunas district and Utena subdistrict of Utena district. In order to evaluation the activity of private farms 300 questionnaires have been collected. As a certain part of respondents have presented all rates of agricultural production, the analysis is carried out considering the data of 291 questionnaire.

Keywords: arrangement of agricultural land, land use, farm development.

• Dr. Pranas Aleknavicius, assoc. prof. of the Land management department, Lithuanian University of Agriculture.

  • Research interests – planning of the territories for agricultural use, coordination of environment protection and agriculture.

  • Address: Lithuanian University of Agriculture, Universiteto 10, LT-4324 Kaunas-Akademija, Lithuania. Tel.: +370 37 75 23 72. E-mail: Pranas@zum.lt.  

• Dr. Vilma Sudoniene, assistant at the Land management department, Lithuanian University of Agriculture.

  • Research interests – planning of the territories for agricultural use, coordination of environment protection and agriculture.

  • Address: Lithuanian University of Agriculture, Universiteto 10, LT-4324 Kaunas-Akademija, Lithuania. Tel.: +370 37 75 23 72. E-mail: Vilmass@delfi.lt.

Article received 04 2003, given to print 05 2003.