Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 50-53). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 83-88). Also available on the World Wide Web.

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2006. / Title from first page of PDF document. Includes bibliographical references (p. 32-35).

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 263 p.; also includes graphics (some col.). Includes bibliographical references (p. 241-263). Available online via OhioLINK's ETD Center

Thesis (Ph. D.)--Texas State University-San Marcos, 2007. / Vita. Appendix: 1 folded map in sleeve. Includes bibliographical references (leaves 95-100).

Thesis (MScEng)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: This study sets out to describe the incipient motion process in cobble/boulder bed rivers in terms of the unit applied power approach. This objective has been met through the collection of data on stone movement from a total of thirteen flood events observed in two undisturbed rivers in the Western Cape, namely the Molenaars and Berg Rivers. The data were plotted on the original modified Liu diagram for incipient motion and it was found that the threshold of movement for the smaller stones did not conform with the portion of the Liu diagram which represents fully turbulent flow (i.e. where ~ gDs tv: = 0.12 for Re. >13). It was concluded that the only reason that could explain this deviation is the fact that the original modified Liu diagram had been derived for uniform particle size beds while the data of the Molenaars and Berg Rivers represent non-uniform particle size beds. This was proved through re-deriving the y-axis function of the original modified Liu diagram to include a factor that makes provision for the roughness of a non-uniform particle size bed. It was found that the average absolute roughness of the non-uniform particle size beds in the Molenaars and Berg Rivers is reasonably well approximated by a value of k=da. Design curves (in terms of the original modified Liu diagram parameters) for intensity of motion were also produced. Although it is not possible to read off accurate percentages of movement values directly from these curves, it should be possible to deduce reasonably accurate values in practical situations. / AFRIKAANSE OPSOMMING: Die studie poog om die begin van beweging proses in klip/rotsbed riviere te beskryf in terme van die eenheids aangewende drywing metode. Hierdie doel is bereik deur die insameling van klipbewegingdata in 'n totaal van dertien vloedgebeurtenisse in twee ongerepte riviere in die Wes-Kaap, naamlik die Molenaars en Bergriviere. Die data was geplot op die oorspronklike aangepaste Liu diagram vir begin van beweging en dit was gevind dat die grens van beweging vir die kleiner klippe nie ooreenstem met die gedeelte van die Liu diagram wat volle turbulente vloei verteenwoordig nie (waar ~ gDs tv; = 0.12 vir Re. >13). Daar was tot die gevolgtrekking gekom dat die enigste rede wat die afwyking kan beskryf is die feit dat die oorspronklike aangepaste Liu diagram afgelei was vir uniforme partikelgrootte beddens terwyl die data van die Molenaars and Bergriviere nie-uniforme partikelgrootte beddens verteenwoordig. Dit was bewys deur die heratleiding van die y-as funksie van die oorspronklike aangepaste Liu diagram om 'n faktor in te sluit wat voorsiening maak vir die ruheid van 'n nie-uniforme partikelgrootte bed. Dit was gevind dat die gemiddelde absolute ruheid van die nieuniforme partikelgrootte beddens in die Molenaars en Bergriviere word redelik goed benaderd met 'n waarde van k=ds4• Ontwerpkurwes (in terme van die oorspronklike aangepaste Liu diagram parameters) vir intensiteit van beweging was ook ontwikkel. Alhoewel dit nie moontlik is om baie akkurate persentasies van beweging af te lees van die kurwes nie, is dit moontlik om akkuraat genoeg waardes te verkry in praktiese situasies.

1. Realigning rivers is becoming common as a solution to conflicting needs of land development and ecosystem preservation. Although an increasing number of projects are monitored, exactly how these channels develop as functional stream ecosystems is still poorly understood. Mining in the upper catchment of the River Nith (Scotland) required the realignment of 3km (approx.) of river. The engineered channel was designed around sound geomorphological principles of sediment transport and supply with a sinuous planform and pool-riffle sequences along the installed gravel-bed. 2. A comprehensive survey covering biotic and abiotic development was devised and implemented to test models and hypotheses relating to the development riverine habitats over the first three years. 2. Physical habitat development at the reach scale was investigated using fixed-point photography and differential GPS surveys of the thalweg and of cross-sectional form every 100m. This revealed the development of a relatively diverse streambed habitat in response to both the channel slope and planform. However, other than at meander bends where asymmetry developed over several years, little change was observed to the form of the engineered riverbanks. 3. Kick-net surveys of benthic invertebrate communities at 10 sites showed a negative relationship between specific measures of diversity and downstream distance during the early stages of development. (e.g. Richness with chainage at the 6 month stage) but the relationship degrades rapidly and is likely in part to appear as a result of low population densities. 4. Survey of transects through the riparian zone perpendicular to the river indicated that colonisation by vegetation is also related to distance along the realignment but physical habitat and geographical factors play a more dominant role over development (Canonical correspondence analysis of vegetation data in 2007) 5. Many of the indices of diversity for both biotic and abiotic elements of the ecosystem proved ineffective at detecting development at the reach scale. This may be because significant changes occur at a smaller scale than was detected by the surveys. It is likely that greater resolution is required to detect more ecologically meaningful relationships and patterns. 6. Overall study shows constructed realignments can rapidly develop a diverse streambed community within 24 months. Riparian communities are slower to develop because of the slow development of riverbank habitat diversity. Other ecosystem properties such as resilience and connectivity may take much longer.

Pre-flood (1995), and post-flood (1996) channel stability surveys were conducted on 22 reaches along Oak Creek, Benton County, Oregon in an effort to note if the flood of February 1996 altered the channel and if the channel stability survey that was being used accurately predicted the channels resistance to change resulting from a flood. The channel stability survey that was used was the method described in the 'Channel Stability Evaluation and Stream Reach Inventory' designed by the USDA Forest Service, Northern Region, in Colorado (Pfankuch, 1978). This was a non-parametric study, based on an opportunity to reoccupy survey locations from a previous study. A model was proposed to describe the 1995 ratings as predictions for change should a flood event occur. This predicted change was compared to the actual change that occurred as a result of the 1996 flood in order to test the surveys ability to accurately predict change. Changes in the survey totals, the 15 channel stability indicator items that compose the survey, and the sediment distribution were evaluated within and between years at the reach, station and stream scale. An increase in the percentage of fine gravel occurred at all scales when post-flood and pre-flood sediment distribution was compared. Except for an increase in fine gravel, the stream remained similar to its pre-flood state. In 1995, the stream's channel stability was rated as 'fair', indicating that a moderate amount of change should take place if a flood occurred. The 1995 predictions for change did not match the actual change observed after the February 1996 flood at the three scales when defined by the survey totals. When independently evaluating the fifteen individual channel stability indicator items, a considerable amount of change was detected at the reach level. Although change occurred in the indicator items at each reach, the stream average for each of the independent indicator items was similar between the two years. This may indicate that, although change occurred at the reach level, the stream maintained its physical diversity after the flood. The survey method was unable to accurately predict changes to Oak Creek incurred by the February 1996 flood when viewed at the entire stream level, yet it may be more applicable at the reach level when viewing specific changes to channel stability indicator items. In general, the Stream Reach Inventory and Channel Stability Evaluation is designed for observational efficiency but does not have sufficient scientific basis or measurement precision to accurately predict the extent or type of channel change. / Graduation date: 1998

No description available.

According to the National Water Act No. 36 of 1998 (DWAF 1999), classification of the water resources in South Africa is the initial step towards the implementation of protection or management programmes. This study reviews different methods and systems of classifying river environments, in order to recommend a convenient, efficient and flexible classification scheme for describing the conditions of river environments. To meet this challenge, the study proposes the use of Geographical Information System (GIS) as a tool to link different controlling variables of river environments and thereafter analyse their spatial relationships. The study supports the use of GIS in river environment classification, with special emphasis on its functionalities that make it possible to explore and manipulate data interactively and easily. The GIS allows the user a flexible way to analyse the geomorphologic and ecological controlling variables of the river system. Thus , it enables different arrangements of these controlling variables for a number of classification purposes. The methodology used involves the GIS (database) analyses and map analyses to explore the relationships between geomorphologic and ecological controlling-variables of the river ecosystem. A case study of the KwaZulu-Natal Rivers demonstrates that valuable information for river environments could be derived from available geomorphologic and ecological datasets using methods of analyses within the GIS. In addition, the case study illustrates that it is possible to develop a working classification scheme for a particular purpose. The developed classification scheme can be improved by considering influential factors such as, the use of up-to-date datasets, consistent projection parameters and relevant scale. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.