Simulations based on a month of radar data from Florida, and a summer of radar data from Nelspruit, South Africa, were used to quantify the errors in the measurement of mean areal rainfall which arise simply as a result of the extreme variability of convective rainfall, even with perfect remote sensing instruments. The raingauge network measurement errors were established for random and regular network configurations using daily and monthly radar-rainfall accumulations over large areas. A relationship to predict the measurement error for mean areal rainfall using sparse networks as a function of raining area, number of gauges, and the variability of the rainfield was developed and tested. The manner in which the rainfield probability distribution is transformed under increasing spatial and temporal averaging was investigated from two perspectives. Firstly, an empirical relationship was developed to transform the probability distribution based on some measurement scale, into a distribution based on a standard measurement length. Secondly, a conceptual model based on multiplicative cascades was used to derive a scale independent probability distribution.

Queensland and much of eastern Australia have had significant rainfall declines since ~1951, causing economic hardship on rural and urban communities. However, no significant attempt has been made to identify and understand the physical causes of the rainfall declines over southeast Queensland (SE QLD) and whether they are likely to continue into the 21st century under higher levels of global warming.In this research, climate observations, models and global climate data as well as palaeoclimate information are used to investigate past, present and future rainfall trends in SE QLD. Five global climate models (GCMs) from the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC–AR4) show a significant decrease in rainfall will occur over the SE QLD region during the 21st century. Observations since ~1951 show the mean sea level pressure (MSLP) has been increasing over much of Queensland, indicating the subtropical ridge has been expanding. This study attributes the increase in the MSLP and some of the rainfall decline to changes in the subtropical ridge and the Southern Annular Mode (SAM). Projections show increases in the MSLP over the region are likely to continue during the 21st century associated with the positive polarity of SAM. Land cover changes over SE QLD were investigated using a regional climate model and show rainfall decreases with higher surface albedo values. Finally, a palaeoenvironmental record developed using lake sediments from Lake Broadwater in SE QLD, indicates a gradual rainfall decline has occurred during the last ~3.2 kyr B.P. Hence SE QLD has undergone a slow rainfall decline since the late Holocene and also since ~1951, with these conditions likely to continue and intensify during the 21st century.

Thesis (M.S. - Renewable Natural Resources)--University of Arizona, 1983. / Includes bibliographical references (leaves 50-52).

Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references.

Thesis (M.S. - Hydrology)--University of Arizona, 1984. / Includes bibliographical references (leaves 122-123).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1986. / Includes bibliographical references (leaves 56-57).

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1986. / Includes bibliographical references (leaves 102-104).

Thesis (M.S. - Hydrology and Water Resources) -- University of Arizona. / Includes bibliographical references (leaves 162-169).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 97-105). Also available in electronic version.

Thesis (M.S. - Hydrology) - University of Arizona. / Includes bibliographical references (leaves 102-105).