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Sea coast - a geomorphic system that maintains its stability through the exchange of sand between its individual elements. As environmental conditions change, the shore system changes by adapting to maintain its stability. Natural processes such as sea level fluctuation and extreme storms cause continuous shoreline change. Feedback effects create natural elements inhibiting external factors altering shore stability. There is a relative equilibrium between natural factors and the shore and in the absence of sudden changes the shore system retains its quasi-stability over a long period of time. This is reflected in the development of the Baltic Sea coast at Lithuania in the 20th century. During this period, of naturally developing coastline did not experience drastic changes. Both the position of the shoreline and the change in the volume of sand on shore did not undergo catastrophic changes. Everything changes radically when a human intervenes in natural processes by starting to develop economic activities on the shore. Especially significant changes occur during the construction or reconstruction of hydro-technical structures. In the case of Lithuania, the hydro-technical structures that caused the biggest changes were the jetties of Klaipeda and Šventoji ports and the pier of Palanga. Since the shore sand transfer resultant at the Lithuanian nearshore is directed from south to north, the resulting barrier cats this drift, disrupting the free circulation of sand along the shore and forcing sand to accumulate on the southern side of the jetty. Meanwhile, on the north side of the jetty, when the sand supply is lost, the coast begins to retreat. These changes are exacerbated by the deepening of the Klaipeda port cana

Sandy coasts are one of the most dynamic spheres, continuously changing due to natural processes (severe weather and rising water levels) and human activities (coastal protection or port construction). Coastal geodynamic processes lead to beach sediment erosion or accumulation. The coast&rsquo, s dynamic tendencies determine the changes in the volume of beach sediments, grain size, mineralogical, and geochemical composition of sediments. In addition to lithological and mineralogical analysis of sediments, geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts&rsquo, conditions. The study aims to assess trace metals&rsquo, temporal and spatial distribution determined in the sandy beach sediments along the south-eastern Baltic Sea coast (Lithuania) during 2011&ndash, 2018. The Lithuanian seacoast is divided into two parts: mainland and spit coast. Our results revealed that the dominant group of elements on the mainland includes Ca&ndash, Mg&ndash, Mn&ndash, Ti and on the Curonian Spit Fe&ndash, Pb&ndash, As&ndash, Co&ndash, Cr&ndash, Ni&ndash, Al, which remain unchanged during the years. The analysis included additional parameters such as beach volume, grain size and sorting, and heavy mineral concentration on the beach. The spatial analysis of trace elements indicated that the trace metal content depends on the coastal processes, but it differs in the mainland and spit sea coast. We identified a higher concentration of trace metals in the erosion-dominated areas in all analysed years on the mainland coast. On the spit coast, the trace metal concentration increased in areas associated with relict coarse sand and where the loading of sediments was active on the beach due to the northward along-shore transport.

This study aims to analyse the spatial lithological and geochemical composition of beach sediments from two sites representing coastal areas with different geological and geomorphological frameworks, sediment availability and sediment transport pathways. The sandy beach surface sediments were sampled in spring 2018, the magnetic susceptibility was measured on-site and the grain size analysis was carried out and the geochemical composition of the samples determined in the laboratory (ICP-MS/ES). The results indicated that even though the sites differed in term of geology and geomorphology, the mean magnetic susceptibly and grain size did not differ significantly. On the contrary, the two sites showed significant differences in elemental composition. The factorial analysis revealed that there were two main groups of elements; the first was composed of Fe–V–Cr–Pb–As–K–Co–P–Ni–Al–Ga, mostly represented in the sediments of the Curonian Spit, and the second group was composed of Mn–Ca–Mg–Sr–Ti–Ba which defined the composition of the sandy beach sediments of the mainland coast. We interpreted the geochemical anomalies as having different causes. On the mainland coast, geochemical and lithological anomalies tend to form where the coastal erosive processes are active, while on the Curonian Spit, these anomalies are located where relict coarse sand dominates and the main unloading of sediments from the alongshore northward current occurs. These results allow the sediment transport process to be better understood and the sediments’ provenance to be identified. In the future, they could also be used for coastal sediment transport modelling exercises.

Summary Dredging entrance channels to ports on open littoral drift seashores often causes major morphological changes to the shoreline. This study aims to assess the impact of dredging the Port of Klaipėda's entrance channel and the construction of the jetties on the coastal zone. Based on an analysis of cartographic material collected between 1835 and 2017, and on field data (bathymetric surveys and cross-shore profile levelling), changes to the coastal zone in the area nearest to the port were evaluated. The dominant longshore sediment transport on the Lithuanian nearshore runs from south to north. Thus, based on established patterns, intensive accretion could have been expected to take place on the southern side of the port jetties and erosion on their northern side. However, in the case of the Port of Klaipėda, in the area nearest to the port on the updrift side of the port jetties, where accretion would have been expected to take place, the nearshore depth increased throughout the 20th century (when the length and configuration of the jetties did not change). The shoreline shifted landward instead of moving further out to sea. The present study shows that the intensive dredging of the entrance channel caused nearshore and shore erosion on the updrift side of the port jetties, even while a sufficient sediment load was being transported by the longshore drift.

Beach-foredune sediment exchange maintains a coastal system&rsquo, s stability. Sea level fluctuation is one of the most important factors that modifies the beach and foredune sediment budget. This study aims to assess beach and foredune sand budget changes depending on sea level fluctuations. On the basis of annual measurements of cross-shore profiles on the Curonian Spit in Lithuania, the sediment volumes on the beach and foredune and their changes between 2002 and 2019 were calculated. The sea level fluctuations were examined in parallel. The obtained data revealed that in the case of a sand surplus, a relatively low sea level rise does not have a significant impact on the development of a foredune (and a minimal impact on a beach) on a decadal time-scale. Short-term sea level fluctuations are reflected in year-to-year variability in a beach sediment budget. However, no significant relationship between year-to-year variability in sea level fluctuation and the foredune sediment budget has yet been identified, nor is there a reliable year-to-year variability relationship between the foredune and beach sediment budget. The foredune sediment budget remained positive both through an increase and a reduction in the sediment volume on the beach.

The geologic framework is an important factor worth consideration when analyzing the development of seacoasts. The different coastal responses to hydrometeorological and anthropogenic factors depend on the composition and amount of original coast-forming sediments. The impact of sediment composition on morphometric parameters is best observed in areas where sand unrepresentative of the adjacent coastal sectors appears on beaches with a relatively uniform lithological composition. These areas are referred to as lithological anomalies. Large amounts of coarse-grained sand, uncharacteristic of the adjacent coastal sectors of the Curonian spit, accumulated in the area of the strait that existed in the Post-Littorina Late Subboreal (3.7–2.5 ka BP) time south of the Juodkrantė settlement. Due to accumulation of coarse sand, the beach in this sector is narrow and has a higher slope, and the ridge is lower and with a smaller volume of sand than in the adjacent coastal sectors. The specific sand composition and morphology of this coastal sector are responsible for different coastal dynamics during storms. During extreme storms, beach erosion in this coastal sector is minimal (sometimes even accretion takes place) compared with other sectors where beach erosion is rather substantial. Meanwhile, during periods of relatively calm weather, i.e. times of expected regeneration of the cross profile, this sector stands out for active erosion processes.

The 98-km-long Curonian Spit is fronted by beaches mainly composed of quartz sand with minor high-density fractions. In this study heavy-mineral concentration (HMC) trends and grain-size statistical parameters were used to assess their role as indicators of natural processes, human activities, and patterns of longshore transport. A total of 92 surface sand samples were collected at 1 km intervals from the middle of the beach along the Baltic Sea shoreline of the spit between Klaipėda strait in Lithuania and Zelenogradsk in Russia. HMC contribution was assessed in the laboratory using bulk low-field magnetic susceptibility (MS) as a proxy for ferrimagnetic and paramagnetic mineral content. Quartz-dominated (background) sand is generally characterized by low MS values of κ 150 μSI are typical for heavy-mineral-rich sand. The greatest MS values along the middle of the beach occur in the southern part of the spit and are 40 times higher than in the northern sector. This pattern suggests the existence of a longshore particle flux with HMC distribution having the potential as a useful tracer of longshore sediment transport. Local anomalously high MS excursions are associated with contribution of iron-rich materials from adjacent man-made structures. Therefore, temporally constrained HMC distribution along the middle of the beach reflects the cumulative effect of antecedent geologic framework, longshore sediment transfer, erosional and accretionary processes, wave and wind climate, and local coastal protective structures.

Jarmalavicius, D.; Smatas, V.; Stankūnavicius, G.; Pupienis, D., and Žilinskas, G., 2016. Factors controlling coastal erosion during storm events. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1112 - 1116. Coconut Creek (Florida), ISSN 0749-0208. Extreme storms may induce major changes in coastal morphology which are usually short-term in nature. The storm-related effects are controlled by different factors such as storm intensity, sand composition and coastal morphology. The main task of this study is to identify the main factors controlling erosion processes in particular coastal sectors during an extreme event. We analysed three major storms that took place over the last 15 years on the Lithuanian Baltic Sea coast: 4th December, 1999, 9th January, 2005 and 11th January, 2015. The scale of storm impact has been assessed through annual...

The complexity of the foredune system is responsible for its morphological diversity and different development scenarios. On wave-dominated coasts, wave activity that permanently changes foredune and beach morphometry is the main limiting factor of foredune development. Based on a field data collected on the Curonian Spit in 2002–2017, the dynamic pattern of the cross-shore profile parameters was determined. There is a close correlation between the foredune height and horizontal distance between the shoreline and foredune top. In foredunes with differing morphology and sedimentology, the established ratio between these indices is rather stable and makes 0.14–0.21 (an average of 0.17). During accretion-dominated periods, with minimal storm surge impact on the foredune, the slope flattens and, under ideal conditions the foredune toe approaches the shoreline, and the stoss slope angle reaches 0.17 (i.e. ∼10°).

The influence of natural and anthropogenic factors on the distribution of sand grain size along sandy beaches is assessed, based on study of three spits of the southeastern Baltic Sea: the Curonian, Vistula and the Hel. 330 sand samples were collected from the beach and foredune at 1 km intervals. Our findings show that although the three spits have some characteristics in common, e.g. a predominance of fine- and medium-grained marine sand on their beaches and foredunes, the grain size distribution patterns of the recent sediments along these spits differ significantly. The key factors determining the grain size distribution include the dominant hydrometeorological regime, anthropogenic activity and geological framework. Trends in the mean grain size differentiation along the Vistula and Curonian spits directly correlate with the direction of the longshore sediment transport: as the distance from sources of the longshore sediment transport increases, the size of sand particles, both on the beach and the foredune, decreases. By contrast, on the Hel Spit, this pattern is disturbed in areas of hydrotechnical construction and artificial beach nourishment. Sand differentiation along the beach can also be predetermined by the geological framework, particularly in lithologically anomalous sections, such as the JuodkrantĹ settlement on the Curonian Spit.

Jarmalavicius, D., Pupienis, D., Žilinskas, G., 2014. Sea level fluctuation and shoreline evolution on decadal time scale, Lithuanian Baltic Sea coast. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 164–169, ISSN 0749-0208. Fluctuations in sea level are reflected in shoreline dynamics. Depending on the nature of the change, the coast is dominated by either erosion or accumulation processes. However, despite considerable attention to this subject, few works have been dedicated to the direct research of coastal development dependence on these determining factors. The objective of this paper was to assess the impact of sea level fluctuations on shoreline dynamics based on coastal monitoring data. The monitoring of coastal dynamics has been carried out since 2002. Annual shoreline displacement was determined based on the obtained data. In addition to morphometric data, sea level...

Pupienis, D., Jarmalavicius, D., Žilinskas, G., Fedorovic, J., 2014. Beach nourishment experiment in Palanga, Lithuania. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13 th International Coastal Symposium (Durban, processes in recreation zones led to shoreline retreat and the volume of beach sand reduced. Increased coastal erosion resulted in diminishing recreational space. In order to rebuild the eroded beaches, a decision to implement a beach nourishment project was made. From 2006 to 2012, through several stages along a 2.5 km stretch of shoreline, over half a million m³ of sand was added to the beach, dredged from the onshore Kunigiskiai sand quarry or offshore from the Baltic Sea floor. From 2004 to 2013, along the nourished stretch, coastal monitoring was carried out once a year in the spring; the beach's condition was assessed based on 10 cross-shore profiles: cross-shore levelling was carried out and sand samples were collected. On the basis of repeated cross-shore levelling, changes in the morphometric characteristics of the beach and dune ridges and sand volume were undertaken. Sand samples allowed the identification of its granulometric composition. The results showed that the shoreline has partially stabilised after the beach reclamation; the beach has become wider and higher, thus recreational conditions have partially improved, i.e. beach recreational space has increased. However, beach nourishment has not changed the coastal dynamic patterns. The beach is relatively stable due to the additional nourished sand. It should be noted that the morphometric parameters of the beach profile depend on the nourished sand volume. Due to the increased beach width, aeolian processes have intensified, resulting in an increased sand volume carried towards the coastal backdune forest. These shore reclamation operations have changed in the prevailing sand's granulometric composition. Previously, predominantly light yellow fine sand was replaced by dark brown medium sand. The beach restoration was the reason for an increase in beach slope.

Pupienis, D., Jonuskaitė, S., Jarmalavicius, D., and Žilinskas, G., 2013. Klaipėda port jetties impact on the Baltic Sea shoreline dynamics, Lithuania. Port of Klaipėda is Lithuanian Baltic Sea harbour, which construction began in 1835. From 1835 to 2002, Klaipėda port gate (jetties and Klaipėda port entrance channel) saw several stages of reconstruction. Within the last reconstruction works of Klaipėda port gate in 2002, the southern and northern port jetties were extended reaching 1300 m and 1400 m respectively, and the entrance channel was dredged to the depth of 14.5 m. The objective of this paper is to determine the tendencies of shoreline variations in the northern part of Klaipėda harbour, at the Melnragė, on the basis of the analysis of cartographic material from different periods (1835–2010), as well as monitoring data on coastal dynamics (1996–2012) and by applying empirical mathematical functions: the parabolic bay equation. The analysis of cartographic material showed that in the nort...

Pupienis, D., Buynevich I.V., Jarmalavicius, D., Žilinskas, G., and Fedorovic, J., 2013. Regional distribution of Heavy-mineral concentrations along the Curonian Spit coast of Lithuania Heavy-mineral concentrations (HMCs) in coastal sands serve as important indicators of hydrometeorological and sedimentological conditions. Along the southeast Baltic Sea coast, quartz- and feldspar-rich sands contain variable amounts (1–8%) of heavy minerals, such as garnet, rutile, zircon, magnetite, ilmenite, hornblende, and other accessory minerals. Their concentrations are found along the Baltic Sea coast of the Curonian Spit, a 98-km-long barrier divided between the Russian Federation (47 km) in the south and the Republic of Lithuania (51 km) in the north. The open sea beach sites range from 25 to 80 m in width and are backed by 5–16 m height foredunes. To examine the patterns in HMC distribution, a total of 303 surface sand samples were collected from the middle of the beach, foredune toe, and stoss slope at...

Pupienis, D., Žilinskas, G., Jarmalavicius, D., Satkūnas, J., 2012. Dynamics of the Nemunas River delta front during the period 1910-2005. Baltica, 25 (1), 45-56. Vilnius. ISSN 0067-3064. Abstract An analysis of changes in the coastline of the Nemunas River delta front was undertaken with GIS based on cartographic material representing a 95 year period. Delta development was analysed comparing two time periods: 1910-1958 and 1958-2005. Quantitative indicators of land area determined during the study in- dicate that land in the northern part of the Nemunas delta front decreased more than 2.1 times in the 1958-2005 period, compared to the previous 1910-1958 period. The main reasons for the decrease of sediment accumula- tion are a decrease Nemunas River runoff, and a similar decrease of sediment particulates, due to anthropogenic activity and natural factors a rise in the water levels of the Baltic Sea and the Curonian Lagoon, as well as land subsidence in the Nemunas delta region.

An analysis of the dynamics of wind velocity along the Baltic coast of Lithuania is presented, based on data collected during field experiments in the summer, fall and winter of 1999-2001 and 2007-2009 at several sites (Būtingė, Saipiai, Smiltynė, Juodkrantė, Pervalka and Nida). The locations were chosen in order to encompass a wide spectrum of beach and dune ridge morphology. The relationship between wind velocity dynamics and coastal morphology was established, based on measurements of the slope angle, height and shape of the dune crest, as well as measurements of the morphology of the area behind the foredune ridge. On the basis of a comparison of near-surface wind velocity patterns, shear velocity (U*) and surface roughness length (z0) were calculated. It was determined that U* decreases from the middle of the beach towards the foredune toe, then increases towards the crest of the foredune and decreases down the lee slope. A direct correlation exists between U* and the stoss slope inclination, and the relative height of the foredune. Surface roughness length also increases from the beach towards the foredune crest.

The investigations were carried out in order to evaluate change of the beaches profile during the period 1993–2008 and to elucidate main trends of the coastal dynamics. Morphometric indicators (beach width, height and inclination) were measured every year during the period 1993–2008 in 70 measuring stations located along the coastline. It was determined that the dynamic shoreline of the mainland during 1993–2008 receded by 10.2 m and the dynamic shoreline of the Curonian Spit advanced into the sea by 8.3 m. The different morphometric beach indicators changed to varying extents over the period 1993–2008, but comparison of values for 1993 and 2008 showed that those changes were small. The average beach width increased by 1.2 m on the mainland coast and by 0.5 m on the Curonian Spit coast. The average beach height also increased negligibly: by 0.5 m on the mainland coast and by 0.1 m on the Curonian Spit coast. The average beach slope inclination increased by 0.012 (from 0.065 to 0.077) on the mainland coast and by 0.005 (from 0.073 to 0.078) on the Curonian Spit coast. The measurements show that, despite being the most dynamic elements in the coastal system, these beaches managed to retain their morphometric indicators almost unchanged during the period of observation.

An intensive abrasion of the coast of the most popular Lithuanian Palanga health‐resort necessitates consideration of the most effective ways of its stabilization. Based on the data of field investigations and literary sources, the possibilities of Palanga coastal zone regeneration using the sand dredged from the entrance channel of Klaipeda port are considered. Based on the current geodynamic trends of Palanga coastal zone and results obtained by comparative analysis of granulometric composition of sediments dredged from the entrance channel of Klaipeda Port, the optimal possibilities of using the dredged sand for coast regeneration were determined. It was established that formation of underwater sandbar (analogue of natural bar) in the surf zone of coastal sector between the Palanga Pier and Birute Mount at a depth of 3 m would be the best solution for coast regeneration under the current conditions. Palangos kranto zonos rekultivavimo galimybių tyrimai Santrauka.Intensyvi populiariausio Lietuvoje Palangos kurorto jūros kranto arda verčia ieškoti efektyvių kranto stabilizavimo metodų. Pastaruoju metu (2003–2008 m.) atlikti apsauginio paplūdimio kopagūbrio tvirtinimo bei paplūdimio sąnašu atsargų papildymo Palangos rekreacinėje zonoje darbai lėmė tik trumpalaikį kranto apsaugos efektą. Straipsnyje, remiantis natūrinių tyrimų bei literatūros duomenimis, įvertintos smėlio, iškasamo iš Klaipėdos įplaukos kanalo, naudojimo Palangos kranto zonai regeneruoti galimybės. Atsižvelgus į dabartines Palangos kranto zonos geodinamines tendencijas bei atlikus šio ruožo ir iškasamo iš Klaipedos uosto įplaukos kanalo birių sąnašų sudėties lyginamają analizę, nustatytos optimalios iškasamo smėlio panaudojimo kranto zonai regeneruoti galimybės. Esant dabartinei situacijai efektyviausias kranto zonos regeneravimo būdas – povandeninio volo (gamtinio sekliaus analogo) 3 m gylyje kranto ruožo tarp Palangos tilto ir Birutės kalno gožos zonoje formavimas. Reikšminiai žodžiai: kranto zonos sąnašų papildymas, dirbtinis sėklius, sąnašų granuliometrinė sudėtis. Исследование возможностей рекультивации береговой зоны Паланги Резюме.Интенсивный размыв морского берега в рекреационной зоне самого популярного курорта Литвы – Палангe вынуждает искать эффективные способы его стабилизации. Выполненные за последнее время (2003–2008 гг.) работы по укреплению дюнного вала и попытка пополнить пляж наносами в береговой зоне г. Паланги дали лишь кратковременный берегозащитный эффект. На основе натурных данных в статье оценены возможности использования для регенерации береговой зоны Паланги песка, выкапываемого из подвходного канала порта Клайпеды. Учитывая полученные результаты исследований современных геодинамических тенденций береговой зоны г. Паланги, состав наносов подвходного канала порта г. Клайпеды и изучаемого участка, установлены оптимальные возможности использования добываемого песка для стабилизации береговой зоны г. Паланги. Установлено, что при нынешней ситуации самым эффективным способом регенерации береговой зоны является формирование подводного вала (аналог природного) в прибойной зоне на глубине 3 метров на участке между Палангским мостом и мысом горы Бируте. Ключевые слова: подпитка береговой зоны, искусственный подводный вал, гранулометрический состав наносов. First Publish Online:21 Jun 2011

Kuršių nerijos formavimasis pasižymi nepertraukiama morfolitologinių rodiklių kaita išilgai jūros kranto. Tačiau tam tikrose vietose ši tolydumo sąlyga erdvėje sutrinka. Šiose vietose pastebimas stiprus morfolitologinių rodiklių reikšmių nukrypimas nuo tolydžios kaitos, sąlygotas paleogeografinių, geologinių, hidrodinaminių, meteorologinių bei antropogeninių veiksnių. Remiantis smėlio dalelių dydžio bei paplūdimio ir kopagūbrio morfometrinių rodiklių kaita, išilgai Kuršių nerijos jūros kranto buvo išskirti kranto ruožai, kuriuose nagrinėjami rodikliai „iškrinta“ iš tolygiai kintančios rodiklių eilės. Nustatyti du ruožai, turintys specifinį rodiklių kompleksą, nesisiejantį su gretimais kranto ruožais: pirmas – Kopgalio ruožas, kurio formavimuisi betarpiškos įtakos turėjo Klaipėdos uosto pietinis molas, ir antras – Juodkrantės ruožas, kurio formavimąsi galėjo lemti visas kompleksas veiksnių: tiek paleogeografinių, tiek hidrodinaminių, tiek ir kitų. Tačiau dėl duomenų stokos tiksli jo genezė nėra nustatyta. Išskirti ruožai yra santykinai stabilūs laiko atžvilgiu ir jų savybės praktiškai nepakito per pastaruosius 20 metų. Nustatyti dėsningumai parodė, kad morfolitologinių rodiklių ekstremalios vertės gali būti laikomos indikatoriais, parodančiais staigų atskiros geosistemos dalies dinamikos pokytį keičiantis hidrometeorologinėms ar antropogeninėms sąlygoms.

Ryškiausi kranto morfologijos pokyčiai fiksuojami prasiautus stipriems štormams bei uraganams, kai per trumpą laiką (keletą ar keliolika valandų) iš kranto išplaunami dideli smėlio kiekiai, paplūdimiai tampa siauri ir lėkšti, kopagūbrio jūriniame šlaite susiformuoja skardžiai. 2015 m. sausio 11 d. siautėjęs stiprus štormas „Feliksas“, nors savo galingumu neprilygo didžiausiems XX a. uraganams, tačiau padaryti nuostoliai kai kuriems Lietuvos jūrinio kranto ruožams buvo reikšmingi. Remiantis natūrinių tyrimų duomenimis, įvertinti išplauto iš paplūdimio ir kopagūbrio bei viso kranto sąnašų kiekiai, nustatytos labiausiai pažeistos ir geriausiai stipraus štormo poveikį atlaikiusios kranto atkarpos. Per stiprų štormą „Feliksas“ Lietuvos jūrinis krantas prarado apie 0,76 mln. m3 sąnašų: 0,39 mln. m3 iš žemyno kranto ir 0,37 m3 mln. iš Kuršių nerijos kranto. Didžiąją nuoplovos dalį (631 000 m3, arba net 80 %) sudarė paplūdimio sąnašos, o kopagūbris nukentėjo sąlyginai nedaug (127 000 m3; arba tik 20 %).

The article deals with trends in Lithuanian coast dynamics analysed on the basis of field investigations performed annually in the 1993–2003 period. During field investigations, measurements of two coastal erosion and regeneration cycles were performed: during two severe storms (13–25 January 1993 and 4–5 December 1993) and two relatively calm weather spans (coastal regeneration) (1994–1999 – before the hurricane ‘Anatoli’ – and 2000–2003). The budget of surface coastal sediments has been chosen as a geoindicator for long-term morphodynamic trends in the coastal zone.

Trends of long-term water level and runoff over the 20th century were analysed based on the data obtained from 12 hydrological gauging stations located on the south and south-east coast of the Baltic Sea, on maximum and minimum water level in the Curonian Lagoon, and on the Nemunas River runoff. It was established that over the 20th century the water level in the south and south-east Baltic Sea (including the Lithuanian coast) and in the Curonian Lagoon had been rising on average at a rate of 1 mm per year, while the Nemunas runoff saw a fall (0.2 km3 per year). Since the mid-1970s in the south and south-east Baltic Sea an acceleration in sea level rise has been observed (at a rate of 5.2 mm per year at Klaipėda). Yet, due to the still falling runoff of the Nemunas the sea level rise has not reflected markedly in the dynamics of the lagoon water level.

As the safe depth for navigation is no longer ensured due to intense accumulation of sediments in the avanport of the old port, which was constructed in 1923–1940, reconstruction of Šventoji port jetties was planned, which should commence in 2013. The assessment of impact of Šventoji port jetties was done on the nearby coasts, based on analysis of the 20th and 21st century cartographic material as well as monitoring data on coastal dynamics. The old port construction caused the formation of the accumulative cape; the area of which has grown to 44.90 ha. The coastline erosion processes have become especially intense northwards from the formed cape to the Latvian border. Approx. 38.41 ha area of land has been washed-out in the section. During the last 17 years, the southern jetty has become more and more pervious to sediments. Sediment volume stabilization occurred on the northern side of the jetty, and accumulation tendency was in the southern part of the port. Results of sediment transport modelling with MIKE 21 confirm that the reconstruction of Šventoji port according to alternative “1” (length of jetties – 400 m) answers the minimal requirements of port and makes the least impact for the hydrodynamic and lithodynamic processes in the Baltic Sea nearshore. The reconstruction of port according to alternative “2” (length of jetties – 800 m) will cause the intensive changes of the Baltic Sea coastline dynamics in adjacent regions. First published online: 14 Dec2012

Straipsnyje, remiantis 2008–2009 m. vykdytų tyrimų metu Palangos rekreacinėje zonoje surinktais duomenimis, analizuojami poilsiautojų srauto sklaidos ypatumai tiek visoje zonoje, tiek ir ją sudaranciose vasarvietėse: Senojoje Palangoje, Kunigiskėse, Užkanaviuose, Monciskėse. Nustatyta, kad didžiausią įtaką poilsiautojų srauto pasiskirstymui tarp vasarviecių turi jų dydis. Nuo jo priklauso poilsio vietų (viesbucių, poilsinių, kempingų ir kt.), automobilių stovėjimo aikstelių, maitinimo įstaigų, pramogų ir pan. skaicius, dažnai ir teikiamų paslaugų kokybė. Todėl didžiausios – Senosios Palangos gyvenvietės – pliažuose ilsisi daugiausia poilsiautojų – net 80,4 % visų besiilsinciųjų Palangos rekreacinėje zonoje. Likusios rekreacinės zonos dalies (Kunigiskės, Užkanaviai, Monciskės) pliažuose ilsisi tik 19,6 % poilsiautojų. Visose jūros krante esanciose vasarvietėse didžiausia poilsiautojų koncentracija susidaro ties pagrindiniais keliais link jūros. Kadangi cia ne tik trumpiausias bei patogiausias priėjimas prie jūros, bet koncentruojasi ir rekreacinės infrastruktūros objektai: automobilių stovėjimo aikstelės, maitinimo įstaigos, sanitarijos ir higienos mazgai, vaikų žaidimo aikstelės, gelbėjimo stotys ir kiti objektai. Nutolusiuose nuo pagrindinių kelių ir neisvystytos rekreacinės infrastruktūros kranto ruožuose poilsiautojų apsilanko mažiausiai.

Paplūdimių morfodinamikos ir kranto linijos dinamikos tendencijos tyrimai Lietuvos jūros krante buvo atliekami 1993–2008 m. Morfometriniai paplūdimio rodikliai (paplūdimio plotis, aukstis ir nuolydis) buvo matuojami kasmet septyniasdesimtyje kranto profilių. Nustatyta, kad žemyno kranto linija per 1993–2008 m. atsitraukė vidutiniskai 10,2 m, o Kursių nerijoje pasistūmė jūros link vidutiniskai 8,3 m. Nors atskirų metų paplūdimio morfometriniai rodikliai gali gerokai skirtis, taciau analizuojant daugiamecius duomenis vidutinis jų pokytis nėra didelis. Per tyrimų laikotarpį vidutinis paplūdimio plotis žemyno krante padidėjo tik 1,2 m, o Kursių nerijos – tik 0,5 m. Vidutinis paplūdimio aukstis taip pat siek tiek padidėjo: 0,5 m žemyno krante ir 0,1 m – Kursių nerijoje. Vidutinis paplūdimio nuolydis padidėjo 0,012 žemyno krante ir 0,005 – Kursių nerijoje. Tyrimai parodė, kad nors per trumpą laikotarpį paplūdimys yra kaiciausias kranto morfologinis elementas, taciau per daugiametį laikotarpį jo morfometriniai rodikliai keiciasi nedaug. Raktažodžiai: Baltijos jūra, Kursių nerija, paplūdimys, paplūdimių morfometriniai rodikliai, kranto linija

Straipsnyje, remiantis 2008-2010 m. vykdytų tyrimų metu Šventosios rekreacinėje zonoje surinktais duomenimis, analizuojami poilsiautojų srauto sklaidos ypatumai tiek visoje zonoje, tiek atskirai ją sudarančiose šiaurinėje ir pietinėje dalyse. Nustatyta, kad didžiausią įtaką poilsiautojų srauto pasiskirstymui tarp atskirų Šventosios miestelio dalių turi jų dydis. Nuo jo priklauso apsistojimo poilsiui vietų (viešbučių, poilsinių, stovyklų ir kt.), automobilių stovėjimo aikštelių, maitinimo įstaigų, pramogų ir kt. skaičius, dažnai ir teikiamų paslaugų kokybė. Kadangi Šventosios miestelio šiaurinė dalis beveik trigubai mažesnė už pietinę, tai ir poilsiautojų jūros krante šioje zonoje ilsisi mažiau nei pietinėje: atitinkamai 34 ir 66 %. Prognozuojama, kad atstačius Šventosios uostą, šiaurinėje rekreacinės zonos dalyje rekreacinė apkrova mažės, o pietinėje – ženkliai padidės. Didžiausia poilsiautojų apkrova jūros krante susidaro ties pagrindiniais keliais link jūros, kadangi čia ne tik trumpiausias bei patogiausias priėjimas prie jūros, bet ir telkiasi rekreacinės infrastruktūros objektai. Nutolusiuose nuo pagrindinių kelių ir neišvystytos rekreacinės infrastruktūros kranto ruožuose poilsiautojų apsilanko mažiausiai. Continuously increasing flow of holidaymakers in the Šventoji recreational zone and the impact this phenomenon has on the physical condition of the coastal territories are gaining special importance in the context of sustainable development. This study concerning the unequal distribution of the flow of holidaymakers on the beaches of the northern and southern parts of the Šventoji recreational zone was carried out in the summers of 2008 and 2009. The investigation was implemented by three observers who simultaneously counted and recorded the numbers of holidaymakers in the locations listed above. The data collection procedure included the following elements: the counting of holidaymakers in two of the above-mentioned areas, i.e. the northern and southern parts of the Šventoji recreational zone and started on the same day at the same time (one o’clock, which is the hour when the numbers of people on the beach reach their maximum); the numbers were recorded every hundred meters (the exact distance being measured by a GPS), and the collected numerical data were later converted into percentages. The study also included the mapping and recording of infrastructure elements in the recreation zones of the marine coast, as well as of the area behind the dunes (approaches to the sea, lifeguard stations, dressing-boxes, benches, garbage bins, litterbins, toilets, public catering facilities, parking lots, etc). This information was used for estimating the impact of recreational infrastructure on the dispersion of holidaymakers on the marine coast. The following conclusions were drawn from the analysis of the collected data. The size of each of the above-mentioned parts of the Šventoji recreational zone, which determines the numbers of rest places (hotels, motels, resorts, etc), catering facilities, entertainment and cultural events, as well as the quality of services, is the main factor responsible for the unequal distribution of the flow of holidaymakers in different coastal areas. The study has indicated that 66% of all holidaymakers in the Šventoji recreational zone concentrate on the beaches of the southern part of Šventoji, which is three times more than in the northern part (with a 34% concentration of all holidaymakers). The largest clusters of holidaymakers occur near the main road accesses to the sea. These areas have greater numbers of parking lots, catering facilities, sanitary units, lifeguard stations and other objects. The recreational load further away from these territories is proportionally smaller. To attain a more even distribution of the flow of holidaymakers along the coastal areas of the Šventoji recreational zone, changes are to be made in the existing infrastructure. More paved roads leading to the beach access (as well as new parking lots) need to be built, and the network of interconnecting trails between these roads should be expanded. [...]

Straipsnyje, remiantis 2008-2009 m. vykdytų tyrimų metu Klaipėdos rekreacinėje zonoje surinktais duomenimis, analizuojami poilsiautojų srauto sklaidos ypatumai tiek visoje zonoje, tiek ją sudarančiose vasarvietėse: I ir II Melnragėje bei Giruliuose. Nustatyta, kad didžiausią įtaką poilsiautojų srauto pasiskirstymui tarp vasarviečių turi jų dydis. Nuo jo priklauso apsistojimo poilsiui vietų (viešbučių, poilsinių, stovyklų ir kt.), automobilių stovėjimo aikštelių, maitinimo įstaigų, pramogų ir kt. skaičius, dažnai ir teikiamų paslaugų kokybė. Todėl didžiausios jų – Girulių pliažuose ilsisi daugiausia poilsiautojų – net 43 % visų besiilsinčiųjų Klaipėdos rekreacinėje zonoje. I Melnragės (mažesnės) pliažuose ilsisi 32 %, o II Melnragės (mažiausios) pliažuose – tik 25 % poilsiautojų. Visose vasarvietėse didžiausia poilsiautojų santalka jūros krante susidaro ties pagrindiniais keliais link jūros. Kadangi čia ne tik trumpiausias bei patogiausias priėjimas prie jūros, bet telkiasi ir rekreacinės infrastruktūros objektai: automobilių stovėjimo aikštelės, maitinimo įstaigos, sanitarijos ir higienos mazgai, vaikų žaidimo aikštelės, gelbėjimo stotys ir kiti objektai. Nutolusiuose nuo pagrindinių kelių ir neišvystytos rekreacinės infrastruktūros kranto ruožuose poilsiautojų apsilanko mažiausiai. Continuously increasing flow of holiday-makers in the Klaipėda recreational zone and the impact of this phenomenon on the physical condition of coastal territories are gaining special importance in the context of sustainable development. This study, concerning the unequal distribution of the flow of holiday-makers in the beaches of three major summer resort areas within Klaipėda’s recreational zone – Melnragė I, Melnragė II and Giruliai – was carried out during the summers of 2008 and 2009. The investigation was implemented by three observers who simultaneously counted and recorded the numbers of holiday-makers in the locations listed above. The data collection procedure included the following elements: the counting of holiday-makers in all three began on the same day at the same time (one o’clock p. m. which is the hour when the number of people on the beach reach their maximum), the calculations were recorded every one hundred meters (the exact distance being measured by a GPS), and the collected numerical data were later converted into percentages. The study included also the mapping and recording of infrastructure elements in the recreation zones of the marine coast, as well as of the area behind the dunes (approaches to the sea, life-saving stations, dressing-booths, benches, garbage bins, waste containers, toilets, public catering facilities, parking sites, etc.). This information was used for estimating the impact of recreational infrastructure on the dispersion of holiday-makers on the coast. The following conclusions were drawn from the analysis of the collected data. The size of each of the above mentioned summer resort settle ments, which determines the numbers of rest places (hotels, motels, resorts, etc.), catering facilities, entertainment and cultural events, as well as the quality of services, is the main factor responsible for the unequal distribution of the flow of holiday¬makers in different coastal areas. The study has indicated that 43% of all holiday-makers in the Klaipėda recreational zone concentrate on the beaches of Giruliai which is the largest of the three summer resort areas, while 32% are estimated in Melnragė I which is lesser in size, and only 25% in Melnragė II. The largest clusters of holiday-makers occur near the main road accesses to the sea. These areas have greater numbers of parking lots, catering facilities, sanitary units, life-saving stations and other objects. The recreational load further away from these territories is proportionally smaller. To attain a more even distribution of the flow of holiday-makers along the coastal areas of Klaipėda’s recreational zone, changes are needed to be made in the existing infrastructure. More paved roads leading to the beach (as well as new parking lots) need to be built, and the network of interconnecting trails between these roads should be expanded. [...]