ABSTRACT In the recent times, due to the increasing rate of global warming, the Southern African region, especially, Lesotho has been experiencing continuous climatic change characterized by drastic reduction in rainfall, increase in the rate of dryness and heat, with depletion of the amount of water, flora and fauna resources. The situation has been so for years without many questions and answers with regard to how it affects food production and security in the country. Against this background, this paper investigates the chain of interactions between climatic change, expressed in the rate of rainfall and drought condition, the indigenous adaptation mechanisms and food production in Lesotho. The paper addresses the estimate of drought condition in Lesotho, Southern Africa, the nature of food production activities in the area and the extent to which continuous climatic change has affected the state of food production.

<p> Low-level clouds found over the eastern subtropical oceans have a substantial cooling effect on Earth&rsquo;s climate since they strongly reflect solar radiation back to space, and their simulation in climate models contributes to large uncertainty in global warming projections. This thesis aims to increase understanding of these marine boundary layer clouds through observational analysis, theoretical considerations, and an evaluation of their simulation in climate models. Examination of statistical relationships between cloud properties and large-scale meteorological variables is a key method employed throughout the thesis. The meteorological environment of marine boundary layer clouds shapes their properties by affecting the boundary layer&rsquo;s depth and structure. </p><p> It is found that enhanced subsidence, typically thought to promote boundary layer cloudiness, actually reduces cloudiness when the confounding effect of the strength of the temperature inversion capping the boundary layer is taken into account. A conceptual model is able to explain this result. Next, fundamental deficiencies in the simulation of subtropical clouds in two generations of climate models are identified. Remarkably, the newer generation of climate models is in some ways inferior to the older generation in terms of capturing key low-level cloud processes. Subtropical mid- and high-level clouds are also found to contribute more to variability in the radiation budget at the top of the atmosphere than previously thought. In the last portion of the thesis, large inter-model spread in subtropical cloud feedbacks is shown to arise primarily from differences in the simulation of the interannual relationship between shortwave cloud radiative effect and sea surface temperature. An observational constraint on this feedback suggests that subtropical marine boundary layer clouds will act as a positive feedback to global warming.</p>

<p> The focus of this mixed-methods study was to identify waste reduction strategies that reduced the impact of California jails and prisons on the environment through waste diversion and reduction. This study also sought to identify barriers that hindered jail and prison personnel from developing such strategies, and pursued recommendations on how those barriers could be overcome.</p><p> Traditionally, California county jails and state prisons are resource intensive, overcrowded housing locations for about 200,000 adult men and women (Glaze &amp; Herberman, 2013). California jails and prisons operate 24 hours a day, seven days a week and utilize resources such as electricity, personnel, food, and other products. Accordingly, they generated significant waste (California Department of Resources and Recovery [CalRecycle], 2012). The prisoners alone generated about four pounds of waste per person each day, consistent with societal averages (CalRecycle, 2012; Corrections Corporation of America, 2007; Environmental Protection Agency [EPA], 2012a). Because of this, jails and prison must do more to reduce waste.</p><p> This study provided examples of organizations currently reducing waste through strategic initiatives and highlighted areas where jails and prisons could begin or further improve waste diversion practices. The study utilized archival data, a web-based survey, and interviews for data collection and analysis. The data from California jails and prisons were analyzed to identify strategies, barriers, and ways to eliminate or reduce barriers to waste reduction programs in California jails and prisons.</p><p> The findings conclude, California state-operated prisons and sheriff-operated county jails are using two primary strategies to divert waste from landfills. The number one strategy is recycling. The second strategy being used is waste prevention and material reuse. The barriers identified by California state-operated prisons and sheriff-operated county jails include finding vendors to collect certain materials as well as finding vendors to travel to remote locations. Other barriers include a lack of personnel and in some instances a lack of knowledge. Sheriff-operated jails and state-operated prisons in California identified waste management program support from leadership as a primary method to eliminate or reduce barriers to implementing a waste reduction program. Implications for action and future research are also discussed as part of this study.</p>

Ice is both an important indicator, and agent, of climate change. In this work we consider conceptual and numerical models of ice in the global climate system on two ends of the climate modeling spectrum. On the simple end of the spectrum, we introduce a low-dimensional global climate model to investigate the role of oceanic heat transport on ice cover, particularly in the initiation of global ice cover, known as Snowball Earth events. We find that oceanic heat transport is effective at keeping the ice margin at high latitudes, and neglecting to include oceanic heat transport can lead to drastically different climate states. On the complex end of the climate modeling spectrum, we implement an iceberg parameterization in the Los Alamos National Laboratory's sea ice model CICE. Novel to our approach is we model icebergs in two frameworks - as Lagrangian particles, and as an Eulerian field. We allow icebergs to interact dynamically with the surrounding sea ice, and the modeled iceberg thermodynamics allow them to melt as they drift, serving as vehicles of freshwater injection into the ocean from land ice sheets. We focus on Antarctic icebergs, which tend to be larger than those found in the Arctic and are more likely to encounter substantial sea ice pack.

<p> Combined effects of socio-economic, environmental, technological and political factors impact fresh cooling water availability, which is among the most important elements of thermoelectric power plant site selection and evaluation criteria. With increased variability and changes in hydrologic statistical stationarity, one concern is the increased occurrence of extreme drought events that may be attributable to climatic changes. As hydrological systems are altered, operators of thermoelectric power plants need to ensure a reliable supply of water for cooling and generation requirements. The effects of climate change are expected to influence hydrological systems at multiple scales, possibly leading to reduced efficiency of thermoelectric power plants. This study models and analyzes drought characteristics from a thermoelectric systems operational and regulation perspective. A systematic approach to characterize a stream environment in relation to extreme drought occurrence, duration and deficit-volume is proposed and demonstrated. More specifically, the objective of this research is to propose a stochastic water supply risk analysis and projection methods from thermoelectric power systems operation and management perspectives. The study defines thermoelectric drought as a shortage of cooling water due to stressed supply or beyond operable water temperature limits for an extended period of time requiring power plants to reduce production or completely shut down. It presents a thermoelectric drought risk characterization framework that considers heat content and water quantity facets of adequate water availability for uninterrupted operation of such plants and safety of its surroundings. In addition, it outlines mechanisms to identify rate of occurrences of the said droughts and stochastically quantify subsequent potential losses to the sector. This mechanism is enabled through a model based on compound Nonhomogeneous Poisson Process. This study also demonstrates how the systematic approach can be used for better understanding of pertinent vulnerabilities by providing risk-based information to stakeholders in the power sector.</p><p> Vulnerabilities as well as our understanding of their extent and likelihood change over time. Keeping up with the changes and making informed decisions demands a time-dependent method that incorporates new evidence into risk assessment framework. This study presents a statistical time-dependent risk analysis approach, which allows for life cycle drought risk assessment of thermoelectric power systems. Also, a Bayesian Belief Network (BBN) extension to the proposed framework is developed. The BBN allows for incorporating new evidence, such as observing power curtailments due to extreme heat or lowflow situations, and updating our knowledge and understanding of the pertinent risk. In sum, the proposed approach can help improve adaptive capacity of the electric power infrastructure, thereby enhancing its resilience to events potentially threatening grid reliability and economic stability.</p><p> The proposed drought characterization methodology is applied on a daily streamflow series obtained from three United States Geological Survey (USGS) water gauges on the Tennessee River basin. The stochastic water supply risk assessment and projection methods are demonstrated for two power plants on the White River, Indiana: Frank E. Ratts and Petersburg, using water temperature and streamflow time series data obtained from a nearby USGS gauge. </p>

In the United States, the flood frequency analysis guidelines described in Bulletin 17B are followed to provide reliable flood discharge magnitude estimates for urban floodplain planning and flood insurance studies. The statistical analysis in Bulletin 17B has various assumptions, including that floods are generated by the same type of atmospheric mechanism (flood homogeneity). However, these assumptions should be carefully assessed before proceeding since they might not always be valid and could increase the potential for flood risk. This study focuses on flood frequency analysis from the perspective of flood heterogeneity, the hydrometeorological genesis of each flood event, in Arizona. This was done by analyzing the occurrence and magnitude of individual flood events, which were classified by their flood-producing atmospheric mechanism. Flood frequency curves were derived for each mechanism and combined using a new approach involving the Partial Duration Series peaks. The combined frequency curves were then compared to curves derived from the standard Bulletin 17B method. Results showed that in southern Arizona, the dominant flooding mechanism is characterized by brief, intense, and localized convective precipitation in the summer. However, the dominant flood-producing mechanism in the central Arizona topographic transition zone and at higher elevations is characterized by prolonged and widespread precipitation from synoptic activity in the winter. Tropical cyclone-enhanced precipitation is also an important, but infrequent, flood-producing mechanism throughout the state. Overall, the dominant mechanism does not necessarily produce the largest floods. In such cases flood heterogeneity can have a strong influence on the discharge estimates for the most extreme upper tail probabilities calculated from the flood frequency analysis. Thus, the most frequent floods may impose very little risk of flooding while uncommon floods can impose a much larger one. These results suggest that the flood homogeneity assumption is not valid in many Arizona watersheds. To produce the most accurate discharge estimates possible, it is critical that both analysts and flood managers become aware of the potential repercussions if these details are overlooked.

No description available.

To study the quality response of beetroot to nitrogen fertilizers, a pot trial was conducted in the glasshouse facility of the Department of Soil, Crop and Climate Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, during the 2011 season. The effect of five nitrogen sources (limestone ammonium nitrate, ammonium nitrate, urea, ammonium sulphate and urea ammonium nitrate) at five nitrogen levels (0, 50, 100, 150 and 200 kg N ha-1) on beetroot (Detroit Dark Red) on a Bainsvlei soil type was investigated. The data collected was analyzed using Tukeyâs Least Significant Difference test, at 5% level of significance to determine statistically significant differences between means. The results showed that all fertilizers used resulted in a reduction in plant height for the first six weeks of growth. Nitrogen application only increased plant height significantly from week 8 where the height of plants that received nitrogen, irrespective of the fertilizer used, were significantly taller than control plants. At week 8 no significant differences in height were noted between various nitrogen application rates, but by week 10 significant differences in plant height were noted between the 50 kg N ha-1 and 150 kg N ha-1 or 200 kg N ha-1 application rates. The findings showed that beet plants reacted better to N-fertilization using ammonium sulphate nitrate and urea ammonium nitrate than other nitrogen sources, although limestone ammonium nitrate and ammonium nitrate also produced improvements in plant growth, whereas plants that received urea showed no improvements. Nitrogen at 100 kg ha-1 resulted in more leaves per plant than its application at other levels. Urea ammonium nitrate as a nitrogen source significantly improved plant leaf area, leaf fresh mass, total fresh mass and root diameter. Application of nitrogen at 200 kg ha-1 also increased leaf area, leaf fresh mass, total fresh mass, beet diameter and beet volume. Urea ammonium nitrate increased leaf dry mass by an average of 397% while the lowest leaf dry mass by (139.42% of control) was observed with the use of limestone ammonium nitrate as a nitrogen source. The greatest leaf dry mass was obtained at the highest rate of nitrogen application (200 kg ha-1) and the lowest leaf dry mass was observed at the control level. Beet yields were found to increase as the nitrogen application rate increased, from 2.99 t ha- 1 in the control treatments to 14.37 t ha-1 in the treatments that received 200 kg N ha-1. Fertilizing with urea ammonium nitrate gave the highest yields (12.17 t ha-1), while using limestone ammonium nitrate gave the lowest yields (9.00 t ha-1). Application of nitrogen at 50 kg ha-1 resulted in firmer beets than nitrogen application at other levels. Beets from plants that did not receive any nitrogen were significantly softer than those that received nitrogen at higher levels. The darkening of beet colour (decrease of L*) was experienced at the control level while the highest changes of colour (increase of L*) was obtained at the highest nitrogen level. Nitrogen at 100 kg ha-1 influenced the lowest change of coefficient a from red to green while the control level resulted in more intensive change. The results showed that nitrogen at the control level led to more intensive changes of coefficient b colours from yellow to blue and its application at the highest level resulted in less intensive changes of coefficient b colours from yellow to blue. Neither nitrogen source nor nitrogen level had any effect on the pH, sucrose or fructose contents of the roots. Application of nitrogen at 150 kg ha-1 resulted in greater total soluble solids content in the roots, while the starch content of plants that received no nitrogen was significantly greater than that of plants receiving nitrogen. Nitrogen application at 100 kg ha-1 and at the control level influenced the glucose content, which was significantly higher in these plants than in those that received 50, 150 and 200 kg N ha-1, however, the highest glucose content of the roots was observed at the control level. Nitrogen application at 200 kg ha-1 resulted in higher nitrogen content in the leaves as compared to application of other nitrogen sources at different levels. Limestone ammonium nitrate influenced potassium content of the leaves more than other nitrogen sources. Nitrogen application at 200 kg ha-1 resulted in a greater calcium content in the leaves than other nitrogen sources. The highest sodium content of the leaves was observed at 150 kg N ha-1 while the lowest sodium content was observed at 50 kg N ha-1. Urea ammonium nitrate had a greater positive influence on the manganese content of the leaves than other nitrogen sources. Plants that received no nitrogen had significantly greater levels of iron in the leaves than at all nitrogen levels. Ammonium nitrate as a nitrogen source influenced the calcium content of the beets more than other nitrogen sources. Other root minerals such as phosphorus, potassium, sodium, magnesium, manganese, copper, iron and zinc were not significantly influenced by nitrogen source or nitrogen level, or the interaction between these factors.

Wetland hydrology controls the function of the wetland ecosystem and hence it is the principal parameter for delineation and management of wetlands. It is defined as the water table depth, duration, and frequency required for an area to develop anaerobic conditions in the upper part of the soil profile leading to the formation of iron and manganese based soil features called redoximorphic features. The redoximorphic features must occur at specific depths in the soil profile with specific thickness and abundance to qualify for a hydric soil indicators. Therefore, hydric soil indicators are used to evaluate the wetland hydrology if such a relationship has been verified. The aims of the study were i) to determine soil variation and hydric soils indicators along a toposequence, ii) to determine the relationships between soil water saturation, redox potential and hydric soil morphological properties and iii) to determine the distribution of soil properties and accumulation of soil organic carbon in hydric and non-hydric soils. The study was conducted at the upper head-water catchment of the Bokong wetlands in the Maloti/Drakensberg Mountains, Lesotho. The soil temperature ranged between -10 and 23°C. The soils had a melanic A overlying an unspecified material with or without signs of wetness, or a G horizon. The organic O occurred in small area. Soil profiles were dug along a toposequence and described to the depth of 1000 mm or shallower if bedrock was encountered. Redoximorphic features were described using standard soil survey abundance categories. Soil samples were collected from each horizon and analysed for selected physical and chemical soil properties. The soils had low bulk density ranging from 0.26 in the topsoil to 1.1 Mg m-3 in the subsoil. Significantly low bulk density was observed in the valleys and highest bulk densities were observed on the summits. The soil organic carbon content ranged between 0.18% in the subsoil and 14.9% in the topsoil. The soil also had a high dithionite extractable Fe (mean 93±53 g kg-1) and low CEC (mean 26±9 cmolc kg-1). Soil pH and CEC were relatively lower in the valleys and higher on the summits. Principal component analysis indicated four principal components accounted for 60% of the total variance. The first principal component that contributed 23% of the variation showed high coefficients for soil properties related to organic matter turnover, the second components were related to inherent fertility, the third and fourth were related to acidity and textural variation. Hydric indicators identified in Bokong were histisols (A1), histic epipedon (A2), thick dark surfaces (A12), redox dark surfaces (F6), depleted dark surfaces (F7), redox depressions (F8), loamy gleyed matrix (F2) and umbric surfaces (F13). The thick dark surfaces with many prominent depletions and gley matrix (A12 and F7) occurred in the valleys, while the midslopes and footslopes were dominated by umbric surfaces (A13). The indicators F6, F7 and F8 were not common. Indicators that were related to the peat formation (A1, A2 and F13) were frequently observed. The relationship between soil water saturation and redoximorphic features was verified by monitoring the groundwater table with piezometers, installed in ten representative wetlands at depths of 50, 250, 500, 750, and 1000 mm for two years from September 2009 to August 2011. Redoximorphic feature abundance categories were converted into indices. Strong correlations were observed between redoximorphic indices and cumulative saturation percentage. The depth to chroma 3 and 4 (d_34) and depth to the gley matrix (d_gley) correlations were R2 = 0.77 and R2 = 74 respectively. All redoximorphic indices were poorly correlated with average seasonal high water table. Strong correlation were also observed between profile darkening index (PDI) and cumulative saturation (R² = 0.88) and weak correlations were observed between PDI and average seasonal high water table (R² = 0.63). A paired t test indicated that soil pH, exchangeable Mg and Na, dithionite extractable Fe and Al were significantly different between hydric and non-hydric soils. Hydric soils had significantly higher Mg, Na and Fe content, and significantly low soil pH and Al content. Generally it appeared that soluble phosphorus, Fe and exchangeable bases accumulated in hydric soils, while the soil pH and Al content decreased. The mean soil organic carbon contents were 3.61% in hydric soils and 3.38% in non-hydric soils. However, non-hydric soil relatively stored more organic carbon (174.4 Mg C ha-1) than hydric soils (155.1 Mg C ha-1). The mean soil organic carbon density of the study area was 166±78.3 Mg C ha-1) and the estimated carbon stored was 21619 Mg C (0.022 Tg C; 1Tg = 1012g) within the 1000 mm soil depth. About 384.9 Mg C was stored in the hydric soils within the study area, which was about 1.9% of the total carbon stored in the area to the bedrok or depth of 1000 mm. Among the wetland types, bogs had significantly higher organic carbon levels (6.17%) and stored significantly higher carbon (179 Mg C ha-1) with at least 44% was store in the A1 horizon. It was concluded that the strong correlation observed between PDI, d_34, d_gley and cumulative saturation representing hydric indicators such as histisols (A1), histic epipedon (A2), umbric surfaces (F13), loamy gleyed matrix (F2) can be used to determine the duration and frequency of the water table in the landscape studied. These hydric indicators can be used to delineate wetlands, however, more indicators can be developed.

A soil surface under production gives a certain yield of a certain crop. In our modern society, any kind of industry must be efficient and has to give profits to its owner. Efficiency of the plant production industry varies greatly from year to year and from place to place. [...]