<p> This is the first study of the karst features found at Moira River karst. This study intends to investigate a number of different karst features of the area rather than concentrating on one highly specific problem. Hopefully this will enable the reader to appreciate the wide diversity of karst able to form within a small area such as Moira karst.</p> <p> The variation in karst features encountered at Moira River ranged from a relatively rare form of karst, called a draped karst, to dissolution patterns (scallops), found within a cave. The draped karst dominates much of the area and is formed by the preferential removal of thin, recessive limestone beds. The overlying, massive bedded unit remains and is "draped" over an underlying massive unit.</p> <p> The river plays a dominant role in the formation of karst features at Moira Karst. It floods quite frequently as evidenced by the number of runoff channels found in the area. The caves at Moira River karst have developed as a short cut across a bend in the river and are fully inundated when the river reaches high flow rates. Karst development does not extend much beyond a range of 300 m from either bank of the river and is concentrated on the east side of the river.</p> / Thesis / Bachelor of Science (BSc)

The dissertation investigates the influence of anthropogenic activities to rivers runoff and water quality. The main object of research is international, the second largest river basins in Lithuania – Lielupė river basin district (RBD). An exclusive trait of Lielupė RBD is especially intensive agricultural activities and karst processes. The primary purpose of this dissertation is estimate the influence of anthropogenic activities to impacts of rivers runoff and water quality in Lielupė river basin district, according to European Union directives, the Republic of Lithuania laws and regulations requirements on water quality. Following tasks are solved in the work: the impact of too wet lands drainage on the river runoff changes, the impact from different pollution sources of anthropogenic activities to rivers water quality. The dissertation is composed of introduction, six chapters, general conclusions, recommendations and references. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the paper, research methodology, scientific novelty and defended statements. The introduction ends in presenting the author’s publications on the subject of the defended dissertation and defining the structure of the dissertation. Chapter 1 revises used literature. It analysis anthropogenic impact of rivers runoff and nutrient migration in the rivers water. It performs the part of mathematical modeling of... [to full text] / Disertacijoje nagrinėjama antropogeninės veiklos įtaka upių nuotėkiui ir vandens kokybei. Tyrimo objektas yra tarptautinis, antrasis pagal dydį Lietuvoje Lielupės upių baseinų rajonas (UBR). Išskirtiniai Lielupės UBR bruožai – ypač intensyviai vykdoma žemės ūkio veikla ir aktyviai vykstantys karstėjimo procesai. Pagrindinis tyrimų tikslas – įvertinti antropogeninės veiklos Lielupės upių baseinų rajone kaitos tendencijas ir įtaką upių nuotėkiui bei vandens kokybei, atsižvelgiant į gamtosauginius ir Europos Sąjungos direktyvų, Lietuvos Respublikos įstatymų ir poįstatyminių aktų reikalavimus vandens kokybei. Darbe sprendžiami šie uždaviniai: pernelyg drėgnų žemių sausinimo įtaką upių vandeningumo kaitai, antropogeninės veiklos sąlygotos sutelktosios ir pasklidosios taršos poveikis upių vandens kokybei. Disertaciją sudaro įvadas, šeši skyriai, bendrosios išvados, rekomendacijos, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Įvadiniame skyriuje aptariama tiriamoji problema, aktualumas, tyrimų objektas, darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos bei disertacijos struktūra. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta antropogeninės veiklos įtakos upių nuotėkiui ir biogeninių medžiagų migracijai analizė. Analizuojamas matematinio modeliavimo vaidmuo upių kokybės išsaugojimo procese. Apibūdinamos... [toliau žr. visą tekstą]

Disertacijoje nagrinėjama antropogeninės veiklos įtaka upių nuotėkiui ir vandens kokybei. Tyrimo objektas yra tarptautinis, antrasis pagal dydį Lietuvoje Lielupės upių baseinų rajonas (UBR). Išskirtiniai Lielupės UBR bruožai – ypač intensyviai vykdoma žemės ūkio veikla ir aktyviai vykstantys karstėjimo procesai. Pagrindinis tyrimų tikslas – įvertinti antropogeninės veiklos Lielupės upių baseinų rajone kaitos tendencijas ir įtaką upių nuotėkiui bei vandens kokybei, atsižvelgiant į gamtosauginius ir Europos Sąjungos direktyvų, Lietuvos Respublikos įstatymų ir poįstatyminių aktų reikalavimus vandens kokybei. Darbe sprendžiami šie uždaviniai: pernelyg drėgnų žemių sausinimo įtaką upių vandeningumo kaitai, antropogeninės veiklos sąlygotos sutelktosios ir pasklidosios taršos poveikis upių vandens kokybei. Disertaciją sudaro įvadas, šeši skyriai, bendrosios išvados, rekomendacijos, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Įvadiniame skyriuje aptariama tiriamoji problema, aktualumas, tyrimų objektas, darbo tikslas bei uždaviniai, aprašoma tyrimų metodika, darbo mokslinis naujumas, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos bei disertacijos struktūra. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta antropogeninės veiklos įtakos upių nuotėkiui ir biogeninių medžiagų migracijai analizė. Analizuojamas matematinio modeliavimo vaidmuo upių kokybės išsaugojimo procese. Apibūdinamos... [toliau žr. visą tekstą] / The dissertation investigates the influence of anthropogenic activities to rivers runoff and water quality. The main object of research is international, the second largest river basins in Lithuania – Lielupė river basin district (RBD). An exclusive trait of Lielupė RBD is especially intensive agricultural activities and karst processes. The primary purpose of this dissertation is estimate the influence of anthropogenic activities to impacts of rivers runoff and water quality in Lielupė river basin district, according to European Union directives, the Republic of Lithuania laws and regulations requirements on water quality. Following tasks are solved in the work: the impact of too wet lands drainage on the river runoff changes, the impact from different pollution sources of anthropogenic activities to rivers water quality. The dissertation is composed of introduction, six chapters, general conclusions, recommendations and references. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the paper, research methodology, scientific novelty and defended statements. The introduction ends in presenting the author’s publications on the subject of the defended dissertation and defining the structure of the dissertation. Chapter 1 revises used literature. It analysis anthropogenic impact of rivers runoff and nutrient migration in the rivers water. It performs the part of mathematical modeling of... [to full text]

Abstract Kaohsiung Harbor is one of the most important international sea ports in the world. Due to the long-standing lack of in-situ current data, the complex variations of the flow field in this basin still remain unclear. As a consequence, the related environmental problems such as oil spills, water quality management and ship maneuvering safety , have long been a great concern in this harbor. The present study is conducted to better understand the flow field in the Kaohsiung Harbor. A series of synoptic flow observations of the Kaohsiung Harbor were conducted by using towed-ADCP or EM current meters. From these observations it can be shown that the flow field of the Kaohsiung Harbor is¡GWater entering the harbor through the second entrance and exiting the harbor through the first entrance during ebbs. During floods the flows are reversed. A 3-D numerical model (from POM) is developed for the Kaohsiung Harbor. The flows are more complicated by the M2 tide driven than by the mixed tide driven. From the results by the M2 tide driven show the ocean current is variable, especially the south ocean current. Therefore, the flows are more complicated owing to the mixed tidal characteristics and shoreline geometry. The maximum current speeds amount to 30 - 40 cm/s in the narrow first entrance and 10 - 20 cm/s in the second entrance. It is clearly demonstrated from the model results that drainage from the Chien-Chen River affects greatly the salinity and circulation patterns of the Kaohsiung Harbor, causing the salinity of the first entrance to be lower than that of the second entrance, and the surface layers flowing outward toward the ocean while the lower layers displaying tidal oscillations. From the modeling results, the influence of the wind on the harbor flows is insignificant and the tide is main force in the harbor. Under the simultaneous forcing of river and wind, flood and ebb tidal streams leaving the two entrances are found to diverge in a flow stagnation area inside the harbor near Pier 45 and 61, respectively. Based on the modeling results, it can be concluded that the main factors affecting the flow patterns of the Kaohsiung Harbor are (1) mixed tidal nature, (2) shoreline geometry and (3) river runoff

The variation of the composition of assemblages and the relative abundance of commercial prawns collected from the coastal waters of Yunlin was studied. The data of shrimp fishery was collected from Jan 1997 to Dec 2008 through the program of Integrated Assessment and Management of Environmental Resources for the Industrial District on the Outer-Bank of Yunlin Islands. The dominant species landed in this area are Parapenaeopsis hardwickii, Metapenaeus ensis, and Penaeus penicillatus. Their peak catch seasons are November to May, March to August, and July to March, respectively. The composition of the assemblages of commercial shrimps belonged to three groups according to the seasons: winter (December to February), spring to summer (March to July), and late summer to autumn (August to November). According to time series analysis, the relative abundance is auto-regressed to that of the previous month and the same month one year age. In addition, Jhuo-Shuei river runoff ware correlated to a significant decrease of the shrimp abundance five months later. Based on this information, we obtained a seasonal and factored ARIMA time series equation of the relative abundance of commercial shrimps.

River discharge can affect ocean surface temperature by altering stratification within the oceanic mixed layer. A hitherto unexplored aspect of present climate is the feedback of river runoff onto climate. This thesis presents an investigation of the impact of global river runoff on oceans and climate using a fully coupled global climate model, Community Climate System Model (CCSM). Two model simulations for a period of 100 years have been carried out: 1) a reference run (CTRL) that incorporates all the features of a global coupled model with river runoff into the ocean embedded in it, and 2) a sensitivity run (NoRiv) in which the global river runoff into the ocean is blocked. Comparison of model climate devoid of fluvial discharge with the reference run reveals the significance of fluvial discharge in the present climate. By the end of 50 years of NoRiv experiment, salinity growth slows down and reaches a quasi-stable state. Regions close to river mouths exhibited maximum salinity rise that can potentially alter local density and stratification. On an average, denser and saltier waters in the NoRiv run annihilate barrier layer and form a deeper mixed layer, compared to CTRL run. Density gradient created by the modulation in salinity set forth anomalous currents and circulation across coastlines that carries coastal anomalies to open ocean, preventing local salinity buildup. Arctic Ocean, Bay of Bengal, northern high latitude Pacific and the Atlantic are the most affected regions in terms of changes in salinity and temperature. Model simulations demonstrate that major transformation in Arctic freshwater budget can have potential impact on northern Pacific and Atlantic climate. In the absence of runoff, global average sea surface temperature (SST) rise by about ~ 0.5oC, with major contribution from northern higher latitude oceans. In the Pacific, high latitude warming is related to deepening of mixed layer as well as the northward transport of low latitude warmer waters. Substantial cooling in the central equatorial Pacific (~1oC during winter) can alter large-scale ocean-atmosphere circulation, including El Niño-Southern Oscillation (ENSO). The reinforcement of Pacific and Atlantic western boundary currents aids the transport of warm saline water from low latitudes to higher latitudes. The results suggest that the river runoff can have potential impact on oceanic climate. Response of Indian summer monsoon rainfall to global continental runoff is also examined. In the NoRiv run, average summer monsoon rainfall over India increased by ~ 0.55 mm day−1. Consistent with the increase in annual average Indian monsoon rainfall, all other northern hemispheric monsoon systems showed an increase, while southern hemispheric monsoons weakened. Associated with enhanced monsoon, the periodicity of ENSO in the NoRiv run changes as a result of cooling tendency in the equatorial Pacific, a sign of consistent La Niña. Equatorial Pacific cooling, in spite of a global ocean warming trend, is found to be primarily because of the enhanced local easterly winds and resultant strong equatorial upwelling. Cold anomaly due to upwelling spread entire equatorial Pacific basin within a span of 50 years. The La Niña situation in the Pacific favored increased monsoon rainfall over Indian subcontinent. Another surprising result of this study is the strengthening of ENSO-monsoon relationship in the NoRiv run. This suggests that the river discharge can be considered as a dampening force in the ENSO-monsoon relationship. Northern hemisphere showed a clear warming in the NoRiv simulation compared to CTRL, the result of which is an enhanced trans-hemispheric gradient. Cross-equatorial winds triggered by this gradient blow from southern hemisphere and shift the Inter Tropical Convergence Zone (ITCZ) northward, increasing the precipitation in the northern hemisphere. The cooling in the eastern equatorial Indian Ocean and the warming in the west, reflected in the increase in number of positive Indian Ocean Dipole (IOD) events (9 positive and 5 negative IOD events in the last 50 years), also favored summer-time rainfall over India.