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A Research Report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, October 2016. / Rainfall is a complex phenomenon, which has previously been explored by assessing rainfall patterns in time and space, typically using ground-based weather stations. Rainfall patterns in southern Africa tend to have a direct impact on vegetation growth and surface water availability, and an indirect impact on animal movement. This study investigated rainfall in Botswana by analysing changes in spatial and temporal patterns from 1998 to 2013, using satellite imagery. Tropical Rainfall Measuring Mission (TRMM) 3B43 dataset (1998-2013) was used to document monthly rainfall magnitude and variability over the 15-year period. Additionally, a GIS spatial analysis approach, the Anselin Local Moran’s I tool, was used to determine changes (i.e. persistence) of rainfall conditions on a year by year basis during the study period. WorldClim precipitation data (1950-2000) were utilised as a longer term average reference dataset against which TRMM data could be compared. This study found that the rainy season consisted of relatively high rainfall magnitudes and variability, while the post rainy season consisted of relatively lower rainfall magnitudes and variability across Botswana. Higher magnitudes persisted into April, indicating the occurrence of late summer rainfall during this observation period. From a regional perspective, the Okavango Delta remained a region of relatively higher rainfall magnitude and variability compared to surrounding regions, regardless of the season. The rainy season was associated with a high frequency of rainfall events above the long term WorldClim average, and the post rainy season with a high frequency of rainfall below the long term WorldClim average. The spatial analysis indicated an annual persistence of high rainfall clusters in northern Botswana, and a persistence of low rainfall clusters in southern Botswana throughout the 15-year analysis. In addition, a progressive drying trend towards the end of the time series was observed. These findings suggest that Botswana has experienced both wetter conditions and drier conditions within the 15-year analysis period, than have been historically documented. The progressive drying trend towards the end of the time series may be indicative of a changing climate in Botswana. However, due to the length of this analysis period it cannot be proven conclusively that the detected wetter and drier conditions, than historically documented, are a signal of climate change. This rainfall analysis provides a comprehensive understanding of recent spatial and temporal rainfall patterns and changes in Botswana. More specifically, this rainfall study fits into a bigger research project focused on herbivore conservation in Botswana. Together, these studies will collectively enable protected areas authorities to better manage herbivore migration, improving conservation in Botswana over time. Ultimately, this study stands to make a positive contribution towards the development of existing conservation practices in Botswana. / LG2017

No presente estudo foi realizado monitoramento de radônio em cavernas distribuídas em três parques estaduais de São Paulo. As concentrações de radônio foram determinadas nas cavernas Morro Preto e Santana pertencentes ao Parque Estadual Turístico do Alto Ribeira (PETAR), na caverna do Diabo pertencente ao Parque Estadual de Jacupiranga (PEJ) e na caverna Colorida localizada no Parque Estadual Intervales (PEI). O monitoramento abrangeu medidas entre Abril de 2009 e Junho de 2010. As concentrações de radônio foram determinadas utilizando a técnica de detecção passiva com detectores de traços nucleares do estado sólido tipo CR-39 e câmaras de difusão NRPB. Os detectores foram expostos em períodos variando desde 30 até 150 dias. As concentrações de radônio variaram de 132 Bq/m3 a 9456 Bq/m3. Os resultados das concentrações de radônio foram analisados juntamente com informações sobre quantidade de chuvas no local monitorado, valores de temperatura interna e externa ao ambiente da caverna Santana e informações da literatura de chuva e temperatura na região para uma possível relação entre as variações nos níveis de radônio e informações climáticas. A determinação de 226Ra em amostras de água coletadas em algumas cavernas e rios da região e de radônio emanado da estalactite coletada na caverna Santana permitiu verificar que o radônio nas cavernas é proveniente das rochas das paredes. A verificação do equilíbrio radioativo entre 222Rn, 218Po e 214Po nos detectores expostos foi prejudicada pelas altas densidades de traços, comprometendo a eficácia da metodologia empregada. A dose efetiva anual foi calculada adotando três valores obtidos da literatura para o fator de equilíbrio. Para o cenário mais realista com fator de equilíbrio igual a 0,5 e considerando 52 semanas de trabalho, a dose efetiva anual foi de 5,1 mSv/a. Para o pior cenário que simula uma situação extrema adotando fator de equilíbrio igual a 1 e 52 semanas de trabalho, a dose efetiva anual é 10,2 mSv/a. Também com informações recebidas de uma empresa de monitoria da região sobre as horas que seus guias turísticos gastam mensalmente no interior das cavernas, foi feita estimativa de dose que resultou em uma dose efetiva anual total de 8,5 mSv/a para fator de equilíbrio 0,5 e, para a pior situação o resultado foi de 17,0 mSv/a para fator de equilíbrio 1. Todas as estimativas de doses mantiveram-se abaixo do limite para dose efetiva anual para exposição ocupacional de 20 mSv/a recomendado pela Comissão Internacional de Proteção Radiológica. / In the present study it was carried out the monitoring of radon in caves distributed among three state parks of Sao Paulo. The radon concentration were determinate in Morro Preto and Santana caves, located at PETAR Parque Estadual Turístico do Alto Ribeira (High Ribeira River Tourist State Park), Diabo cave, situated in PEJ Parque Estadual de Jacupiranga (Jacupiranga State Park) and Colorida cave located in PEI Parque Estadual Intervales (Intervales State Park PEI). The monitoring covered measurements between April 2009 and June 2010. Radon concentrations were carried out by using the technique of passive detection with CR-39 solid state nuclear track detectors and NRPB diffusion chambers. The detectors were exposed in periods ranging from 30 to 150 days. Radon concentrations varied from 132 Bq/m3 to 9456 Bq/m3. The values of radon concentrations were analyzed together with information about rainfall and internal and external temperature values of the Santana cave environment and regional literature values for a possible relationship between radon variations and weather information. Both the determinations of 226Ra in water samples collected in some caves and rivers and radon emanation from a stalactite collected at Santana cave allowed to verify that the radon in the caves comes from the walls rocks. The verification of the radioactive equilibrium between 222Rn, 218Po and 214Po in the exposed detectors was prejudiced by the high tracks densities, committing the methodology effectiveness. The annual effective dose was calculated for three values obtained from the literature for the equilibrium factor. Considering the most realistic scenario, with equilibrium factor of 0.5 and 52 working weeks, the annual effective dose was 5.1 mSv/y. Concerning the worst scenario, which simulates an extreme case, adopting an equilibrium factor equal to 1 and 52 weeks of work per year, the annual effective dose is 10.2 mSv/y. Also with information received from a monitoring company in the region about the hours their touristic guides spent monthly inside the caves, it was estimated the received dose that resulted in a total annual effective dose of 8.5 mSv/y, considering an equilibrium factor 0.5 and, for the worst scenario of an equilibrium factor of 1, the result was 17.0 mSv/y. All estimated doses values are below 20 mSv/y, which is the upper limit of annual effective dose for occupational exposure recommended by the International Commission on Radiological Protection.

O presente trabalho teve por objetivo realizar a caracterização silvigênica de um trecho de Floresta Ombrófila Densa Sub Montana em conjunto com o estabelecimento de possíveis relações entre as alterações espaciais do mosaico silvático e os fatores abióticos (solo e topografia). O método utilizado foi o de interceptação de linhas de inventário, com identificação das ecounidades descrito por Torquebiau (1986). Foram dispostas linhas paralelas entre si e distantes 10 m uma da outra. Todos os indivíduos dominantes (mais altos naquele ponto), cujas projeções horizontais das copas interceptaram as linhas, foram amostrados na caracterização silvigênica. Foram tomadas medidas, de no mínimo quatro pontos, da projeção horizontal da copa destes indivíduos até as linhas de inventário, em um sistema de eixos ortogonais (coordenadas x e y). Cada árvore marcada no campo foi classificada, quanto à sua arquitetura, em: árvores do futuro, árvores do presente e árvores do passado (OLDEMAN,1987). As áreas de clareira que interceptaram as linhas também foram amostradas, medidas e mapeadas. O estabelecimento das diversas ecounidades em cada trecho amostrado é feito a partir da união das copas de árvores de mesma categoria. O desenho do mosaico e o cálculo das áreas das ecounidades foram feitos por meio do programa TNTmips, a partir das coordenadas das copas dentro das linhas de inventário. Este trabalho resultou na representação gráfica da cobertura vegetal da área estudada e a sua correlação com os fatores abióticos. Para avaliar o papel dos fatores abióticos na composição espacial do mosaico vegetacional, foram analisadas e combinadas as diversas informações em um Sistema de Informações Geográficas (SIG). Para tal, cada \"classe\" de informação constitui um plano de informação ou um \"layer\" dentro do SIG. De acordo com os resultados pode-se concluir que a caracterização silvigênica indicou que a área estudada representa uma floresta em fase de pré-maturidade por apresentar sinais de perturbações recentes, traduzidas nas altas proporções de ecounidades 1A e em reorganização observadas. Conclui-se ainda quepode ser estabelecida uma relação entre a distribuição das ecounidades e os fatores abióticos estudados. / This study aimed to realize the silvigenic characterization of a Dense Rain Forest in according to the establishment of possible relationships between spatial changing\'s on the silvatic standards and some abiotic factors, such as soil and topography. The method applied was the inventory line interception, identifying the ecounits described by Torquebiau (1986). There were set parallel lines in every 10 meters. All dominant trees (the highest in that point), whose horizontal canopy projections intercepted the inventory line, were sampled in the silvigenic characterization. To measure the canopy projection, there were used at least four points on the inventory line as an orthogonal axis system (X and Y coordinates). Each sampled tree was classified based on its architecture features as: trees of the future, trees of the present or trees of the past (OLDEMAN, 1987). The gap surface crossing inventory lines were also measured and mapped. The ecounit establishment is created by the connection of canopies from the same category (future, present or past). The ecounits design were mapped and its surface measured using the TNTmips software, based on all canopies coordinates over the inventory lines. The study resulted in the graphic representation of vegetation coverage and its correlation with abiotic factors. To evaluate the contribution of the abiotic factors on the vegetation mosaic`s spatial composition, a Geographic Information System (GIS) was settled to combine and analyze all data. Different information classes were overlapped as layers on the GIS environment. According to the results it`s possible to conclude that silvigenic characterization indicates that the studied area represents a pre mature forest, based on recent disturbances sings, confirmed on high rates of ecounits as 1A or reorganization types. It is concluded that the silvigenic mapping represented the architectural behavior of the species related to the soil classification.

No presente estudo foi realizado monitoramento de radônio em cavernas distribuídas em três parques estaduais de São Paulo. As concentrações de radônio foram determinadas nas cavernas Morro Preto e Santana pertencentes ao Parque Estadual Turístico do Alto Ribeira (PETAR), na caverna do Diabo pertencente ao Parque Estadual de Jacupiranga (PEJ) e na caverna Colorida localizada no Parque Estadual Intervales (PEI). O monitoramento abrangeu medidas entre Abril de 2009 e Junho de 2010. As concentrações de radônio foram determinadas utilizando a técnica de detecção passiva com detectores de traços nucleares do estado sólido tipo CR-39 e câmaras de difusão NRPB. Os detectores foram expostos em períodos variando desde 30 até 150 dias. As concentrações de radônio variaram de 132 Bq/m3 a 9456 Bq/m3. Os resultados das concentrações de radônio foram analisados juntamente com informações sobre quantidade de chuvas no local monitorado, valores de temperatura interna e externa ao ambiente da caverna Santana e informações da literatura de chuva e temperatura na região para uma possível relação entre as variações nos níveis de radônio e informações climáticas. A determinação de 226Ra em amostras de água coletadas em algumas cavernas e rios da região e de radônio emanado da estalactite coletada na caverna Santana permitiu verificar que o radônio nas cavernas é proveniente das rochas das paredes. A verificação do equilíbrio radioativo entre 222Rn, 218Po e 214Po nos detectores expostos foi prejudicada pelas altas densidades de traços, comprometendo a eficácia da metodologia empregada. A dose efetiva anual foi calculada adotando três valores obtidos da literatura para o fator de equilíbrio. Para o cenário mais realista com fator de equilíbrio igual a 0,5 e considerando 52 semanas de trabalho, a dose efetiva anual foi de 5,1 mSv/a. Para o pior cenário que simula uma situação extrema adotando fator de equilíbrio igual a 1 e 52 semanas de trabalho, a dose efetiva anual é 10,2 mSv/a. Também com informações recebidas de uma empresa de monitoria da região sobre as horas que seus guias turísticos gastam mensalmente no interior das cavernas, foi feita estimativa de dose que resultou em uma dose efetiva anual total de 8,5 mSv/a para fator de equilíbrio 0,5 e, para a pior situação o resultado foi de 17,0 mSv/a para fator de equilíbrio 1. Todas as estimativas de doses mantiveram-se abaixo do limite para dose efetiva anual para exposição ocupacional de 20 mSv/a recomendado pela Comissão Internacional de Proteção Radiológica. / In the present study it was carried out the monitoring of radon in caves distributed among three state parks of Sao Paulo. The radon concentration were determinate in Morro Preto and Santana caves, located at PETAR Parque Estadual Turístico do Alto Ribeira (High Ribeira River Tourist State Park), Diabo cave, situated in PEJ Parque Estadual de Jacupiranga (Jacupiranga State Park) and Colorida cave located in PEI Parque Estadual Intervales (Intervales State Park PEI). The monitoring covered measurements between April 2009 and June 2010. Radon concentrations were carried out by using the technique of passive detection with CR-39 solid state nuclear track detectors and NRPB diffusion chambers. The detectors were exposed in periods ranging from 30 to 150 days. Radon concentrations varied from 132 Bq/m3 to 9456 Bq/m3. The values of radon concentrations were analyzed together with information about rainfall and internal and external temperature values of the Santana cave environment and regional literature values for a possible relationship between radon variations and weather information. Both the determinations of 226Ra in water samples collected in some caves and rivers and radon emanation from a stalactite collected at Santana cave allowed to verify that the radon in the caves comes from the walls rocks. The verification of the radioactive equilibrium between 222Rn, 218Po and 214Po in the exposed detectors was prejudiced by the high tracks densities, committing the methodology effectiveness. The annual effective dose was calculated for three values obtained from the literature for the equilibrium factor. Considering the most realistic scenario, with equilibrium factor of 0.5 and 52 working weeks, the annual effective dose was 5.1 mSv/y. Concerning the worst scenario, which simulates an extreme case, adopting an equilibrium factor equal to 1 and 52 weeks of work per year, the annual effective dose is 10.2 mSv/y. Also with information received from a monitoring company in the region about the hours their touristic guides spent monthly inside the caves, it was estimated the received dose that resulted in a total annual effective dose of 8.5 mSv/y, considering an equilibrium factor 0.5 and, for the worst scenario of an equilibrium factor of 1, the result was 17.0 mSv/y. All estimated doses values are below 20 mSv/y, which is the upper limit of annual effective dose for occupational exposure recommended by the International Commission on Radiological Protection.

Climatic trends in most parts of the world show a significant increase in rainfall amount, intensity and its frequency. Similarly, these trends are likely to continue in future as well. The major catastrophe caused by these rainfall trends comes as flooding, which is getting harder to predict, and mainly over the mountainous regions. Modelling these extreme rainfall events is crucial, which needs better forecasting skills and more understanding of existing Numerical Weather Prediction (NWP) modelling setup. Although, recent developments in NWP models increase the capabilities to simulate rainfall more precisely but the strengths and weaknesses of model need to be evaluated based on climatic conditions, terrain characteristics -- which include landuse, topography, new physical schemes and static datasets. Therefore, we have conducted comprehensive sensitivity and qualitative analysis with a numerous model setup, physical schemes and terrain datasets. / We contemplate various physical parameterizations and updated terrain datasets to simulate the rainfall over the complex topography using WRFV3-ARW modelling system. Additionally, the impact of topography and landuse on rainfall are discussed in detail along with a several combinations of newly available land surface, planetary boundary layer (PBL), cumulus, and cloud microphysics (MP) schemes. As a case study, we select the north region of Pakistan, which includes Khyber-Pakhtunkhwa (KPK) province and part of Hindukush-Karakoram-Himalaya (HKH), and this region have diversified the landscape and complex topographic features. For the sake of better understanding and comparative discussions, we study three extreme rainfall events; two of them occurred during monsoon period (i.e., July), while one in post monsoon period (i.e., September). / WRF-ARW 3.5.1 model is tuned and tested with GFS0.5 and CFSR/CFSv2 as forcing and lateral boundary conditions with a number of parameterization schemes. Similarly, to minimize the errors induced by terrain features, we apply wind correction and drag parameterizations. Furthermore, 3-arc-second hydrologically corrected SRTM digital elevation model (DEM), modified MODIS IGBP 30-arc-second, MODIS 15-arc-second and GLCNMO2008 landuse datasets were also integrated to WRF along with default datasets in WRF modelling system. / We verify the simulated rainfall by using observed, the Tropical Rainfall Measuring Mission (TRMM) and the Climate Prediction Centre morphing method (CMORPH) rainfall datasets. The GIS-based verification technique, called fisher-net is also introduced which is more compatible and flexible with other tools as well. / 隨著全球氣候變化的加劇，強暴雨極端天氣事件呈現突發、多發、併發的特點，其頻次、強度、持續時間、籠罩範圍近年來均呈現急速上升的趨勢。如何構建高時效性、高精度和高可用的極端天氣事件模擬工具，已經成為災害應急管理與回應等領域迫切需要解決的關鍵科學問題。作為極端天氣事件類比的核心，數值氣象模型對極端暴雨事件的模擬能力日益完善；然而，到目前為止，氣象模型的可靠性和有效性評價仍是其推廣應用的關鍵，特別是如何顧及土地利用類型、地形、新型物理機制和多源靜態資料庫前提下的模型可靠性評價仍面臨很多挑戰。因此，本文提出了顧及不同物理機制、地形特徵的模型構建、模型敏感性評價和定量分析方法。 / 首先，本文在顧及不同的物理參數和地形特徵的基礎上，利用WRFV3-ARW 建模系統實現了對複雜地形特徵下降雨過程的類比與分析。在此基礎上，本文充分考慮和利用新的土地下墊面、行星邊界層、積雲以及雲微物理機制，以詳細分析了地形和土地利用類型對降雨影響。實驗選用具有複雜地形結構和特徵的巴基斯坦北部的Khyber-Pakhtunkhwa (KPK)省和部分Hindukush-Karakoram-Himalaya (HKH) 區域；為了獲取更充分的分析結果，本位對該實驗區域內三次極端降雨事件進行了模擬和分析，包括季風期（例如七月）的兩次降雨事件和季風期過後（例如九月）的一次降雨事件。 / 其次，本文利用GFS0.5 和 CFSR/CFSv2 作為強迫和側邊界條件，設置多參數方案對WRF-ARW 3.5.1 模型進行了優化和測試。與此同時，為了降低由地形特徵導致的類比誤差，本文引入了風向糾正參數和風阻參數。除此之外，本文充分利用了水文糾正過後的3 弧秒精度的SRTM DEM 資料、30 弧秒精度的MODIS IGBP 資料、15 弧秒精度的MODIS 資料、GLCNMO2008 格式的土地利用資料、以及WRF 建模系統的預設資料，支撐WRF 的建模過程。 / 最後，為了驗證本文實驗結果的可靠性，本文利用TRMM 獲取的實測降雨量資料以及TRMM 提供的降雨資料庫驗證，基於GIS 的漁網驗證法，對上述模擬結果進行了詳細的分析 / Sultan, Shahzad. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 111-125). / Abstracts also in Chinese. / Title from PDF title page (viewed on 09, September, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.