Thesis (Ph. D.)--University of New South Wales, 1999. / Also available online.

Thesis (Ph. D.)--University of Washington, 1986. / Vita. Bibliography: leaves [157]-174.

Bibliography: pages 122-129. / Soil erosion is regarded as a serious problem throughout the world. Erosion is caused by both water and wind. Although the two usually occur together, wind erosion has received little attention with the exception of the problems associated with croplands. Wind erosion can, however, also be a serious problem in natural grazing lands. In this research project an attempt is made to determine the areas of potential wind erosion in the Cape Province through the use of two different models. The models used were developed and applied in semi-arid areas and thus were considered to be applicable in South Africa. The models used are: The Wind Erosion Equation developed by Chepil, Woodruff and Siddoway in the United States; and Lynch and Edward's Model for the Analysis of Limited Climatic Data, developed in Australia. There are two aspects to soil erosion by wind - the erodibility of the soil as determined by moisture, grains size, aggregates, plant cover and surface topography; and soil erosivity as determined by wind strength and duration. Methods to control wind erosion are based on decreasing erosivity through the establishment of shelterbelts and by decreasing erodibility through improving plant cover, aggregate stability and moisture retention properties. Efforts at wind erosion measurement are generally ineffective. A number of models have been developed to overcome these difficulties and to allow for prediction of soil loss. Two of these models are applied to conditions in the Cape Province. This area covers a wind range of climatic, soil and agricultural conditions and as such provides an appropriate area for their application. It is, however, concluded that neither of these models can be directly applied to conditions in the Cape Province. The seasonal rainfall distribution and the uneven distribution of the data points contribute to the ineffectiveness of the models. The greatest problem, however, is the importance of management in determining whether or not wind erosion occurs. As a result, although the models illustrate the general climatic trends affecting the susceptibility of an area to wind erosion, the lack of a management factor accounts for the lack of detail.

Call number: LD2668 .T4 1959 L95

No description available.

Thesis (Ph. D.)--Washington State University. / Includes bibliographical references.

Call number: LD2668 .T4 1962 A74

This study uses a very high resolution numerical weather prediction (NWP) model to investigate the complex structure and behaviour of cold fronts along the New South Wales coast during the warmer months of the year, the complex interaction between the wind flow and coastlines and elevated areas as well as the lee-trough effect, particularly the way it affects waters off the east coast of Tasmania, The study also investigates the utility of the higher resolution NWP model to better predict wind fields compared to a lower resolution model. The University of New South Wales very high resolution model (HIRES), nested in the Australian Bureau of Meteorology's coarse NWP model (GASP), was run at various horizontal resolutions (from 15 to 25km) in order to investigate the above-mentioned features. It was found to bave very good skill in resolving the features and was also found to be very accurate in the prediction of surface wind fields for various yacht race events out to at least four days ahead. It can be concluded that there is considerable skill in the ability of high-resolution NWP models such as HIRES, to predict the major features of the wind fields over the ocean out to several days ahead. Moreover, it was also able to more accurately simulate the complex structure of the summer-time cool change as it progressed along the NSW coast than the lower resolution model runs. The influence of coastlines, particularly ones with complex topographical features, on the wind flow was demonstrated to a limited extent throughout the study. Finally the following concepts were also verified as a result of the study: - air flow takes the path of least resistance - the shape of topography can help generate local turbulence - the orientation of the wind flow to a mountain range is important in determining turbulent effects. - under certain airflow and stability situations, standing wave activity and a lee trough can be observed in the lee of mountains, hills or even high coastal cliffs.

Thesis (M.S. in biological systems engineering)--Washington State University, December 2007. / Includes bibliographical references (p. 41-45).

Master of Science / Department of Agronomy / DeAnn R. Presley / Through the 2007 Energy Independence and Security Act, the U.S. government has set goals to decrease fossil fuel use and sustainably produce ethanol from biomass, rather than existing corn grain-based ethanol. In southwest Kansas, crop residues are necessary to protect soil from erosion and to contribute to soil organic carbon (SOC) levels, a key factor in most desirable characteristics of soil quality, and are positively related to soil and crop productivity. Our objective was to quantify the effect of different residue management treatments (residue continuously retained, residue continuously removed, and alternating year residue removal) on soil physical properties, chemical properties, and corn yield. For 2.5 years, measurements and samples were collected from a Hugoton loam (L) and Bigbow fine sandy loam (FSL) in southwest Kansas. Residue continuously removed decreased water stable aggregates ≥ 0.25 mm and mean weight diameter of aggregates in contrast to residue continuously retained treatments following two winter seasons at the Bigbow FSL site. In residue continuously removed treatment for the Bigbow FSL, dry aggregate size distribution (ASD) measurements at the soil surface in the fine sandy loam had higher levels of soil % < 0.84 mm (wind erodible fraction) during the winter season of 2008-2009 and 2009-2010 by 6% and 15%, respectively. No significant differences in wet aggregate stability and ASD were measured at the Hugoton L site. Soil temperature and moisture levels monitored during the winter season showed a higher frequency of freeze-thaw cycles, which can be destructive to aggregates, in residue continuously removed plots. During the winter seasons of 2008-2009 and 2009-2010, the residue continuously removed treatments experienced three more freeze-thaw cycles than the residue continuously retained treatments in the Bigbow FSL soil. Bulk density measurements were variable, and no significant differences due to residue treatment were observed in both the loam and fine sandy loam. Total C, N, and exchangeable K were significantly different in residue continuously retained and removed plots due to residue treatment following 1 year of establishment of the study in the FSL. Total C was 14 g kg-1 and 8.7 g kg-1 in the residue continuously retained and removed treatments, respectively. Total N was 0.3 g kg-1 higher in the residue continuously retained versus the residue continuously removed treatment in the FSL. Irrigated continuous corn in southwest Kansas produces a lot of biomass, and has been reported to create emergence problems in the past. Corn emergence was slightly higher in residue continuously removed treatments in both the spring of 2009 and 2010, but differences were insignificant. No significant treatment effects on corn grain yield were observed in the duration of the study.