Thesis (M.S.)--Ohio University, November, 1993. / Title from PDF t.p.

Thesis (Ph. D.)--McMaster University, 1997. / Includes bibliographical references. Also available via World Wide Web.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.S.)--Michigan State University. Dept. of Agricultural Economics, 2008. / Title from PDF t.p. (viewed on Aug. 5, 2009) Includes bibliographical references (p. 82-86). Also issued in print.

No description available.

The Association for Rural Advancement (AFRA) has run a Drought Project since October 1992. The project's primary focus was to monitor drought conditions in the AFRA's operational area and to assist communities to access relief through providing them with relevant information and helping them to submit proposals to relief agencies. In attempting to do this, it became clear that the effects of drought on rural black communities was not a well understood phenomenon. We also found that relief strategies were informed more by economic, agricultural and meteorological criteria than social ones. This Special Report aims to contribute to the development of a more appropriate drought management strategy, especially with regard to rural communities. In attempting to make this contribution, the Report examines the factors involved in redefining drought and drought relief perspectives in relation to rural communities. However, the range of factors involved and the scarcity of useful information on them, dictate that this is merely an introduction. The complexities and implications arising from the introduction of these factors into drought management in South Africa should be explored on an on-going basis. Because of the scarcity of relevant information about the effects of drought on black rural communities in South Africa, this Report has relied on AFRA's limited monitoring of such communities. Some information was also gathered through Participatory Rural Appraisal (PRA) methods. There were also difficulties in getting information about relief schemes and their operations as most relief agencies were reluctant to release this information. As a result, almost all the relief related information in this Special Report was obtained from publications and reports of the National Consultative Forum on Drought.

Streamflow records in many regions of Eurasia including South Asia are short and fragmentary. This makes it challenging to contextualise natural climate variability relative to anthropogenic climate change and evaluate the severity of recent extreme events. In the first section of the dissertation (Chapter 1 and 2) we use tree rings to reconstruct centennial-scale streamflow of the Indus and Brahmaputra Rivers in South Asia for the past six centuries. These two rivers and their tributaries are fed by Himalayan glaciers and the South Asian Monsoon and are the basis of economic, social, and cultural life of over 700 million people in the region. These centennial reconstructions of past discharge provide valuable information about long-term hydroclimate variability, drought and flood hazard. They also help us to interpret recent climate extremes relative to those in the past and benchmark projections of climate change for the region. Large tropical (and extratropical) volcanic eruptions can release large quantities of reflective sulphate aerosols into the stratosphere where they may persist for up to 3 years. In Chapter 3 we discuss how these aerosols can impact European and Mediterranean hydroclimate by causing dry conditions over northwestern Europe and the British Isles and wet conditions over the western Mediterranean. We examine this hydroclimate response using Superposed Epoch Analysis (SEA), a statistical method used to identify consistent responses to events by testing for the possibility of random occurrence. Finally, in Chapter 4 we describe in further detail (cf. Chapter 3) the modified double-bootstrap SEA that we developed in Chapter 3 to examine the uncertainty inherent in SEA within a probabilistic framework. We describe our modified SEA by applying it to two datasets, a reconstruction of northern hemisphere summer temperature for the past millennium, and a compilation of tree ring fire scar records for the western U.S. Using these two datasets we examine post-eruption northern hemisphere cooling following volcanism and the synchrony between drought conditions and fire events in the western U.S. respectively.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2016. / The drought-stricken, eastern Kalahari region of South Africa is a water stressed region that is solely dependent on groundwater for its water supply. This resource is of primary importance in supplying safe drinking water to the inhabitants of both the towns and rural areas within this region, there being no other alternative. This situation can prove precarious, as the poorly understood complexities of the nature and behaviour of groundwater in this region has often led to over utilisation of the resource in some parts. The efficient and sustainable use of groundwater is paramount to ensure the sustainable and equitable development of the region. As such, an attempt was made to contribute to the understanding of the groundwater potential of this region by examining a number of the hydrogeological factors at play. The total resource potential for the entire study area is estimated at 10,127.29 x 106 m3/a, with the Kalahari aquifer showing the greatest potential in the study area, comprising 50.67 % of the total resource. The storage capability of the Kalahari aquifer (5478.52 x 106 m3) is also impressive, estimated to be more than twice that of the dolomite (2727.99 x 106 m3). This significant storage space of the Kalahari aquifer can allow groundwater recharge to be stored for several decades or even millennia, thereby providing a vital buffer against climate variability. Despite having such great potential, the aquifer is not actively recharged and is often associated with very saline water that is not suitable for human and livestock consumption. As such, although showing the most potential for storage, exploitation of this resource is restricted. The limestones and dolomites of the Campbell Rand and Schmidtsdrif Subgroups are considered as the most prospective water bearing formations in the study area, largely owing to weathering and karstification processes that have made them prolific aquifers and have aided significantly in their resource potential estimated at approximately 1980.65 x 106 m3/a. Although this area shows potential for higher yielding boreholes (> 5 l/s), this particular aquifer does not display hydraulic continuity, with poor water exchange between compartments, resulting in variations in yield and the amount of recharge available. Unlike the Kalahari, these aquifers cannot sustain abstraction through periods of drought, there being no natural regulation to their outflow, as such, caution has to be exercised over how much of the groundwater can in fact be abstracted from this aquifer. The weathered granitic rocks of the Archaean basement within the south-central portion of the study area show favourable resource potential (1844.71 x 106 m3/a) and are typically associated with the better quality groundwater in the study area. The groundwater has moderate salinity and is not as “hard” as the water associated with the karstic and Kalahari aquifers. Unfortunately, however, it is this aquifer that is commonly exploited, particularly for intensive irrigated agriculture. Although isotopic evidence suggests the presence of recent recharge, this aquifer receives most of its recharge from the outcropping areas of the aquifer, with the remaining 70 % of the area being overlain by thick deposits (> 15 m) of Kalahari sediment, which retain a large amount of the recharge from where it is lost by evapotranspiration. As such, if this aquifer is to be utilised sustainably and its use ensured for future generations, stricter controls need to be placed on the volume of water abstracted, particularly by irrigated agriculture. Aquifers with the least potential in the study area generally comprise the fractured basement rocks of the Kraaipan - Amalia greenstone belt, with a resource potential of 26.45 x 106 m3/a, and the fractured sedimentary rocks of the Asbestos Hills Subgroup, with a resource potential of 108.33 x 106 m3/a. While these aquifers offer poor prospects of securing large volumes of groundwater, with the groundwater being primarily confined to their fracture systems, these aquifers offer some of the best recharge areas within the study area. Their isotopic signature seems to suggest that recharge is taking place from the surrounding high ground, where surface and structural controls are responsible for the regional hydraulic continuity. Under favourable conditions, these aquifers may also recharge the adjacent karstic and granitic aquifers, where local structures enable limited lateral and vertical displacement. Overall, the calculated groundwater storage and resource potential within the study area satisfies a large proportion of the water demand in the eastern Kalahari region of South Africa. If each aquifer could be sustainably utilised, a considerable volume of water could be abstracted at an assurance of supply similar to that of surface water. The emphasis, however, is placed on “sustainable exploitation”, as groundwater in this region is also vulnerable to quality degradation and over-exploitation. This often stems from the poorly understood nature of groundwater and the hydrogeological factors at play in the region. The key challenge, therefore, relates to the effective management of the resource, with all role players involved in this complex system working together to achieve the goal of maintaining the quality of the water and ensuring that it is used sustainably, protecting it for future generations. / LG2017

No description available.

Agricultural vulnerability is generally referred to as the degree to which agricultural systems are likely to experience harm due to a stress. In this study, an existing analytical method to quantify vulnerability was adopted to assess the magnitude as well as the spatial pattern of agricultural vulnerability to varying drought conditions in Southern Alberta. Based on the farm reported data and remote sensing imagery, two empirical approaches were developed to implement vulnerability assessment in Southern Alberta at the quarter-section and 30 meter by 30 meter pixel levels. Cereal crop yield and the Standardized Precipitation Index (SPI) were specified as the agricultural wellbeing and stress pair in the study. Remote sensing data were used to generate cereal crop yield estimations, which were then implemented in vulnerability quantification. The utility of the remote sensing data source for vulnerability assessment were proved. The spatial pattern of agricultural vulnerability to different severity and duration of drought were mapped. / xii, 127 leaves : ill. ; 29 cm.