Estudo sistemático de sítios com estruturas de terra em vala (mais conhecidos por \"geoglifos\") na calha direita do médio rio Guaporé, entre as cidades de São Francisco do Guaporé e Costa Marques, estado de Rondônia. Nesta região - nos limites sudoeste da floresta tropical que recobre a maior parte da bacia Amazônica - o conhecimento prévio de tais estruturas levou à prospecção e, com efeito, identificação de novos sítios a partir da análise de imagens aéreas disponibilizadas pelo programa Google Earth 5.1. Posteriormente, a recuperação de uma série de dados sobre estes sítios foi analisada de forma comparada aos demais sítios arqueológicos com estruturas de terra similares conhecidos no sudoeste da bacia Amazônica através de um SIG (Sistema de Informações Geográficas) criado com o auxílio do programa ArcGIS 10.1. Além dos dados desse levantamento e da análise cruzada entre os atributos físicos e formais dos sítios levantados (tanto através da bibliografia consultada quanto através dos novos levantamentos remotos) esta dissertação apresenta também pequeno histórico de pesquisas sobre o tema, os conceitos teóricos que norteiam o seu estudo bem como a metodologia empregada durante seu levantamento e análise. / This work presents the general survey for new archaeological sites with anthropogenic ditched earthworks (also known as \"geoglyphs\" in Brazil) founded at the right margin of the middle Guaporé river, estate of Rondonia, Brazil. In this region - at the limits of the southwestern boarder of the Tropical Rain Forest in the Amazon river basin - the preview knowledge of structures like the ones cited above lead to the discovery of new sites out of the satellite imagery recovered from Google Earth software. After the discovery of these sites, their physical and formal attributes were analyzed comparatively with similar archaeological sites founded in western amazon with the help of an GIS (Geographical Information System) created in the ArcGIS ArcGIS 10.1 software platform. Beside the data from this survey and the comparative analysis made of them, this work also presents a little summary of the research focused on the theme, the theoretical concepts and the methodology used in the survey and analysis of these archaeological sites.

Magistrantūros studijų baigiamajame darbe analizuojama Klaipėdos rajono melioruotų žemių ir melioracijos statinių būklė. Darbo apimtis 48 puslapiai kompiuteriu spausdinto teksto, įskaitant 2 lenteles ir 29 paveikslus. Naudotos literatūros sąrašą sudaro 21 literatūros šaltiniai. Darbo tikslas - atlikti melioruotų žemių ir melioracijos statinių būklės analizę. Nepriklausomybės metais, skiriant melioracijos darbams mažiau lėšų, melioracijos statinių būklė palaipsniui blogėjo. Remiantis naujausiais 2009 metų duomenimis, Klaipėdos rajone neveikiančio arba blogai veikiančio drenažo plotas sudarė 5579,28 ha, o išbrauktas iš apskaitos plotas sudarė 867,45 ha. Viso to pasekmė yra ta, kad melioruota žemė nebuvo dirbama, drenažo rinktuvai užsikimšo medžių ir augmenijos šaknimis, pamiškėje drenuoti plotai užaugo menkaverčiu mišku, krūmais. Šiuo metu magistralinių griovių ilgis Klaipėdos rajone yra 1280 km, iš kurių 70,87 km blogos būklės. Kaip ir visi melioraciniai statiniai, taip ir grioviai nėra amžini. Nuslinkus šlaitui, nusėdus dugne nešmenims, priaugus žolių, patekus įvairiems kliuviniams, sugriuvus pralaidoms ir drenažo žiotims, grioviai praranda savo paskirtį ir patvenkia drenažo sistemas, sumažina drenažo veikimo efektyvumą, pablogindami dirbamų žemių sausėjimą. Taigi, tvarkingas griovys sąlygoja normalų vandens ištekėjimą iš drenažo žiočių ir daugeliu atvejų padeda išvengti brangių drenažo sistemos rekonstrukcijos darbų. Lietuvoje yra 56808 pralaidų, iš kurių 23322 yra blogos... [toliau žr. visą tekstą] / In the final work of master studies, we analyse a state of reclaimed lands and reclaimation constructions in Klaipėda region. The work consists of 48 pages of printed text, including 2 tables and 29 pictures. Twenty-one references have been used. The aim of the final work is to analyse a state of reclaimed lands and reclaimation structures. During the years of independence, with less means being assigned for land reclamation works, the technical state of land reclamation structures gradually became worse. According to the newest inventory data of 2009, the area of badly functioning or non-functioning drainage made up 5579,28 ha, whereas the area deleted from the accounting made up 867,45 ha. Consequences of all that are: reclaimed lands were not cultivated, drainage manifolds became obstructed with roots of trees and vegetation, and the drained areas on the forest outskirts overgrew with not valuable forests and shrubs. At present the length of main ditches in Klaipėda district is 1280 km, 70,87 km of which are in bad state. All land reclamation structures, ditches as well, are not everlasting. Ditches lose their purpose due to slope slippage, sediment deposition, grass overgrowth, and culvert or drainage mouth collapse. They overflow drainage systems as well as decrease the efficiency of drainage systems and reduce the draining of cultivated lands. Thus, ditches that are in good condition determine the regular water outflow from the drainage mouth and, in many cases help to... [to full text]

Magistrantūros studijų baigiamajame darbe analizuojama griovių ir juose esančių statinių būklė Šakių rajone. Darbo apimtis 61 puslapis kompiuteriu spausdinto teksto, įskaitant 8 lenteles ir 29 paveikslus. Naudotos literatūros sąrašą sudaro 24 literatūros šaltiniai. Darbo tikslas – atlikti griovių ir juose esančių statinių būklės analizę Šakių rajone. Nepriklausomybės metais, skiriant melioracijos darbams mažiau lėšų, melioracijos statinių būklė palaipsniui blogėjo. Remiantis naujausiais 2007 metų inventorizavimo duomenimis, Šakių rajone neveikiančio arba blogai veikiančio drenažo plotas sudarė 5641,32 ha, o išbrauktas iš apskaitos plotas sudarė 144,7 ha. Viso to pasekmė yra ta, kad melioruota žemė nebuvo dirbama, drenažo rinktuvai užsikimšo medžių ir augmenijos šaknimis, pamiškėje drenuoti plotai užaugo menkaverčiu mišku, krūmais. Šiuo metu magistralinių griovių ilgis Šakių rajone yra 1239,30 km, iš kurių 613,77 km blogos būklės. Kaip ir visi melioraciniai statiniai, taip ir grioviai nėra amžini. Nuslinkus šlaitui, nusėdus dugne nešmenims, priaugus žolių, patekus įvairiems kliuviniams, sugriuvus pralaidoms ir drenažo žiotims, grioviai praranda savo paskirtį ir patvenkia drenažo sistemas, sumažina drenažo veikimo efektyvumą, pablogindami dirbamų žemių sausėjimą. Taigi, tvarkingas griovys sąlygoja normalų vandens ištekėjimą iš drenažo žiočių ir dageliu atveju padeda išvengti brangių drenažo sistemos rekonstrukcijos darbų. Lietuvoje yra 56808 pralaidų, iš kurių 23632 yra blogos... [toliau žr. visą tekstą] / In the final work of master studies is analysed the state of trenches and theirs constructions in Sakiai region. The work consists of 61 pages of printed text, including 8 tables and 29 pictures. 24 references have been used. The aim of the final work – to summarize the whole information about trenches and their existent buildings in Sakiai region. During the independent years, with less means being assigned for land reclamation works, the technical state of land reclamation structures worsened in time. According to the newest inventory data of 2007, the area of badly functioning or non-functioning drainage made up 5641,32 ha, whereas the area deleted from the accounting made up 144,7 ha. Such situation occurred because of the following facts: reclaimed lands were not cultivated, drain manifolds became obstructed with the roots of trees and vegetation, on the forest outskirts the drained areas overgrew with not valuable forests and shrubs. At present the length of the main ditches in Sakiai district is 1239,30 km, of which 613,77 km are in bad state. Ditches, as all land reclamation structures, are not imperishable. After the slope slipping, the depositing of sediments, the overgrowing with grasses, the collapse of culverts and drainage mouth ditches loose their purpose and overflow drainage systems as well as decrease the efficiency of drainage systems and worsen the draining of cultivated lands. So, ditches that are in good condition determine the regular water outflow from... [to full text]

Estudo sistemático de sítios com estruturas de terra em vala (mais conhecidos por \"geoglifos\") na calha direita do médio rio Guaporé, entre as cidades de São Francisco do Guaporé e Costa Marques, estado de Rondônia. Nesta região - nos limites sudoeste da floresta tropical que recobre a maior parte da bacia Amazônica - o conhecimento prévio de tais estruturas levou à prospecção e, com efeito, identificação de novos sítios a partir da análise de imagens aéreas disponibilizadas pelo programa Google Earth 5.1. Posteriormente, a recuperação de uma série de dados sobre estes sítios foi analisada de forma comparada aos demais sítios arqueológicos com estruturas de terra similares conhecidos no sudoeste da bacia Amazônica através de um SIG (Sistema de Informações Geográficas) criado com o auxílio do programa ArcGIS 10.1. Além dos dados desse levantamento e da análise cruzada entre os atributos físicos e formais dos sítios levantados (tanto através da bibliografia consultada quanto através dos novos levantamentos remotos) esta dissertação apresenta também pequeno histórico de pesquisas sobre o tema, os conceitos teóricos que norteiam o seu estudo bem como a metodologia empregada durante seu levantamento e análise. / This work presents the general survey for new archaeological sites with anthropogenic ditched earthworks (also known as \"geoglyphs\" in Brazil) founded at the right margin of the middle Guaporé river, estate of Rondonia, Brazil. In this region - at the limits of the southwestern boarder of the Tropical Rain Forest in the Amazon river basin - the preview knowledge of structures like the ones cited above lead to the discovery of new sites out of the satellite imagery recovered from Google Earth software. After the discovery of these sites, their physical and formal attributes were analyzed comparatively with similar archaeological sites founded in western amazon with the help of an GIS (Geographical Information System) created in the ArcGIS ArcGIS 10.1 software platform. Beside the data from this survey and the comparative analysis made of them, this work also presents a little summary of the research focused on the theme, the theoretical concepts and the methodology used in the survey and analysis of these archaeological sites.

Large areas of northern Sweden have been ditched to promote forest growth by draining wet soils and peatlands. These ditches have greatly added to length of Sweden’s stream and river network, but the ecological properties of these man-made aquatic environments is poorly understood. The aim of this thesis was to evaluate the extent to which forest ditches support benthic macroinvertebrate communities, test the factors might influence variation in these communities across ditches, and evaluate how these communities differ from those observed in more natural headwater streams. To do this, I analysed macroinvertebrate family richness and community composition from 16 sampling sites distributed across two ditch networks in northern Boreal Sweden. At each site, I also compiled information related to channel structure, water depth, and the upstream distance from more typical headwater streams. I then tested whether variation in community metrics among ditch sites was related to differences in local habitat properties as well in the spatial position of sites within the ditch network.  Finally, I used existing data from four headwater streams within the same broader catchment to evaluate how these communities compare with those observed in forest drainage ditches. Results showed that macroinvertebrate family richness and community composition varied among ditch sampling sites, but that these systems supported a range of aquatic taxa that are typically found in headwater streams.  Overall, family richness tended to increase among ditch sampling locations that had greater water depth at the time of sampling and that were located further downstream in the ditch network. In addition, sampling locations with mineral substrate tended to support communities with a greater representation of more sensitive aquatic orders when compared to sites dominated by peat sediments. Finally, while family richness was not significantly different between ditches and headwater streams, benthic communities in streams were dominated by different set of taxa that reflect greater flow velocity and better overall water quality conditions.  Overall, my results suggest ditches in the boreal forest landscape can support benthic communities that closely resemble what is observed in headwater streams. However, ditch habitats were also highly variable, with several sites indicating poor local habitat conditions for many benthic organisms.  Hydrological patterns, including water depth, but also unmeasured variables like flow velocity and the potential for seasonal drying likely play a key role in influencing the ecological properties of ditches in these landscapes.

No description available.

Low grade rip rap weirs installed in agricultural surface drainage ditches manage downstream eutrophication by slowing water flow, allowing sediments time to settle out of the water column and phosphorus (P) to sorb to soil. A laboratory experiment was conducted in microcosm chambers to simulate increased hydraulic residence time caused by weirs and two field studies were conducted to compare experimental data with field data and determine sediment deposition rates. One field study monitored weirs monthly after installation and the other measured weirs of varying ages. Weirs retained significantly more water and sediment than controls. Longer inundation times led to abiotic factors known to release P during hydrologic flux, but did not translate to reduced P storage. By converting intermittently inundated sediments into more consistently saturated sediments, weirs function as a viable conservation practice for about a year until temporary P retention mechanisms and sediment retention capacities are reached.

No description available.

The state of roadside ditch design and performance has become a topic of concern for the Virginia Department of Transportation. Erosion failures of roadside ditches have occurred frequently enough to indicate that it may be desirable to revise the current design practice. Through the Virginia Transportation Research Council, VDOT has sponsored this research to investigate the state of design practice for these structures and to explore revisions to the design process resulting in a more economical design. To investigate the erosion problems, various VDOT personnel at each of Virginia's nine Construction Districts were interviewed with the intent to gain an understanding of roadside ditch performance in each District. When possible, field visits were made to sites experiencing erosion failure and soil samples were collected for analysis. In addition, experiences and design procedures in neighboring states were reviewed, with the objective of determining if similar problems have been experienced, and if so, how they have been addressed. The survey of other states included nine states, and a site visit to the Mount Airy District of the North Carolina Department of Transportation. A study of the literature relating to the hydraulic performance of unlined and lined ditches was also performed, with the objective of researching available stability criteria used in ditch design and determining if suitable values of Manning's n are being used in Virginia design. The results of this study presented in this thesis represent the best recommended roadside ditch design practice based on current available research. Recommendations include revisions to the current relationship of soil type and maximum allowable velocity, revisions to the application of Manning's n for various lining conditions, and suggestions to improve the overall design and construction process based on surveyed VDOT experience, surrounding states and current research. Future research will be necessary to improve the scientific bases for these recommendations / Master of Science

Die Hochmoore des Erzgebirges sind auf Grund ihrer jahrhunderte langen Nutzung und der ökosystemaren Wandelprozesse der vergangenen 10 - 15 Jahre unterschiedlich stark degradiert. Gleichzeitig sind sie durch den Austrag vergleichsweise hoher Austräge von DOC (Dissoloved Organic Carbon) gekennzeichnet. Um den Zusammenhang zwischen dem Zustand der Hochmoore, als Ergebnis in erster Linie der unterschiedlich nutzungsbedingten Degradation und den Stoffausträgen speziell den DOC-Austrägen zu erfassen, wurden mittels landschaftsökologischer Methoden Hochmoortestflächen verschiedener Zustände vergleichend untersucht. Die Ergebnisse lieferten erste Hinweise, dass in Flächen mit natürlicher Regeneration oder anthropogener Wiedervernässung vergleichsweise hohe DOC-Konzentrationen und – Austräge zu beobachten waren. Demgegenüber standen stärker degradierte Flächen mit zum Teil aktueller forstlicher Nutzung (geräumte Entwässerungsgräben), die durch geringere DOC-Konzentrationen und – Austräge charakterisiert waren. Da die gefundenen Zusammenhänge nicht endgültig belegt werden konnten, besteht insbesondere Forschungsbedarf hinsichtlich landschaftshaushaltlicher Untersuchungen unterschiedlich degradierter Hochmoore im Erzgebirge. / Natural peat bogs are known as a sinks especially for carbon because of theire special matter and water balance. The use of peat bogs requiers their drainage, but consequently the peat will decompose unreversible and peatlands turn to a source esspecially for carbon. The peat bogs in the “Erzgebirge Mountains” were used over several centuries. Thats why the peatlands existing nowadays have different states dependent on the duratian of their use. Beside the use peatlands were mostly negativly effected by processes of ecological change in the “Erzgebirge Maountains” in the last 10 to 15 years. As one result of ecological change the increased output of DOC (Dissolved Organic Carbon) into surface waters can be seen. The main source for DOC are peatlands. By the way it seems to exist a connection between the output of DOC and other dissolved substances and the state of the peatlands especially of their ditches. To research this hypothesis four test areas of different state were chosen. Their state and the output of DOC and other dissolved substances were investigated with methods from landscape ecology from 2001-2003. It was the first time, that peatlands in the “Erzgebirge Mountains” were investigated in such a way. The badest state had the test area where the ditches were cleaned in 2000/ 2001 (“Weiße Mulde”, Western “Erzgebirge Mountains”). This test area showed the lowest but constant DOC-concentrations and DOC-output during the investigation period. The test areas “Carlsfeld” and “Löffelsbach” (Western “Erzgebirge Mountains”) had the best state. The state of “Carlsfeld” is related to the narueal closed ditches, which cause the processes of self regeneration. Due to such processes the DOCconcentrations were distinctly higher but very variable in dependence on weather and runoff. The same was supposed to DOC-output. The same valuation got the test area “Löffelsbach”, because of rewetting by technical closed ditches in 2001. During the investigation period the highest DOC-concentrations of all test areas were measured there. Similar to “Carlsfeld” DOC-concentrations and –output were highly variable in dependence on weather and runoff. The state of the test area “Salzflüßchen” (Eastern “Erzgebirge Mountains”) is also related to processes of self regeneration but was valuated bader than “Carlsfeld”, because the effect of former drainage was stronger in this area. In 2005 the rewetting of the test area is planed by “Naturpark Erzgebirge/ Vogtland”. In the consequence the DOC-concentrations and –output will increase similar to “Löffelsbach”. The results of the investigations indicate that a connection exists between state of peatlands and output of dissolved substances esspecially DOC. The results are supported by national and international literature. It will be clear, that more research is necessary especially on the field of comparative investigations of peatlands with different states in the “Erzgebirge Mountains”.