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Each year, the urbanised population grows exponentially and due to this growth, cities are forced to expand beyond their manageable borders resulting in greater pressure on the surrounding urban environment. Many South African towns or cities are dependent on surface water for water supply. These resources are slowly being depleted and the dependence on groundwater resources is becoming increasingly important. Due to increased mining, industrial and agricultural activities in South Africa the surface water and groundwater environments have become vulnerable to contamination. This study aimed to develop a methodology in which the risks of urbanisation can be quantified. The conceptualisation and qualitative site impact and risk assessments focused on any environmental changes. The urban environment was sub-divided into three distinct areas and analysed separately in order to detect possible groundwater impacts of the water flowing through the urban area. Upstream river flow gauge chemistry by way of tri-linear grouping (piper diagram) of the major anions and cations showed already impacted water due to mining activities north of Potchefstroom. Uranium concentrations in the downstream surface water showed negligible impact as the concentrations remained within the relevant standards over time. Total coliform bacteria concentrations were found to be well above the acceptable levels and these high concentrations are an indicator of water purification inefficiency. Different qualitative risk assessment approaches i.e. the Environmental Risk Assessment method, Fuzzy Logic and the Depth to water, recharge, Aquifer media, Soil media, Topography, Impact of the vadose zone media and Conductivity of the aquifer (DRASTIC) approach risk assessments were compared and used to determine the most effective way to determine the most likely risks associated with urbanisation. Different modelling tools namely, analytical element modelling method (AEM) using the Visual AEM program, a finite difference numerical modelling method using Processing Modflow v.8 (PMWin) were evaluated, however due to insufficient data, an analytical approach had to be developed. This approach incorporated logical steps and associated processes to serve as a guide for future urban hydrogeological investigations. A case study (namely Potchefstroom) was used to test the developed methodology. The developed methodology provides a step by step approach to urban risk assessment, even in areas where there is insufficient data. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Each year, the urbanised population grows exponentially and due to this growth, cities are forced to expand beyond their manageable borders resulting in greater pressure on the surrounding urban environment. Many South African towns or cities are dependent on surface water for water supply. These resources are slowly being depleted and the dependence on groundwater resources is becoming increasingly important. Due to increased mining, industrial and agricultural activities in South Africa the surface water and groundwater environments have become vulnerable to contamination. This study aimed to develop a methodology in which the risks of urbanisation can be quantified. The conceptualisation and qualitative site impact and risk assessments focused on any environmental changes. The urban environment was sub-divided into three distinct areas and analysed separately in order to detect possible groundwater impacts of the water flowing through the urban area. Upstream river flow gauge chemistry by way of tri-linear grouping (piper diagram) of the major anions and cations showed already impacted water due to mining activities north of Potchefstroom. Uranium concentrations in the downstream surface water showed negligible impact as the concentrations remained within the relevant standards over time. Total coliform bacteria concentrations were found to be well above the acceptable levels and these high concentrations are an indicator of water purification inefficiency. Different qualitative risk assessment approaches i.e. the Environmental Risk Assessment method, Fuzzy Logic and the Depth to water, recharge, Aquifer media, Soil media, Topography, Impact of the vadose zone media and Conductivity of the aquifer (DRASTIC) approach risk assessments were compared and used to determine the most effective way to determine the most likely risks associated with urbanisation. Different modelling tools namely, analytical element modelling method (AEM) using the Visual AEM program, a finite difference numerical modelling method using Processing Modflow v.8 (PMWin) were evaluated, however due to insufficient data, an analytical approach had to be developed. This approach incorporated logical steps and associated processes to serve as a guide for future urban hydrogeological investigations. A case study (namely Potchefstroom) was used to test the developed methodology. The developed methodology provides a step by step approach to urban risk assessment, even in areas where there is insufficient data. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

Today, only 7 % of the Atlantic Rainforest, that once covered Brazil, remains scattered across the southern parts of the country. As the forest is rapidly disappearing, the government of Brazil has emerging interest of preservation. Thus more and more areas are turned into national parks and reserves. At the outskirts of one of these reserves, the Iracambi research station is situated. The center makes an effort to carry out applied research to find methods of preserving and learning about the forest. It is within that context the project described in this report has been performed. The project aimed to establish a water balance over Graminha Basin, the main river in the Iracambi research area. By doing this the understanding of the fluctuations of the amount of water in the ecosystem could increase. An important part of the objective was also to assess which methods can be used practically at Iracambi.The project was carried out during the rainy season from February 13th to April 12, 2012. During this time the water flow was measured at five stations along the river, using a current meter and instant slug-injection. Between six and fifteen flow measurements were made at each station. Slug- injection was generally the most suitable gauging method to use in the area. Precipitation was measured at two points. Evaporation was measured using an evaporation pan, and also calculated using the Penman-Monteith equation. Even though, the parameterization of the Penman-Monteith needs to be improved it was deemed to be the more suitable method for the area.The results give a rough estimate of the water balance during the period. It was concluded that the storage decreased during the project period. Based on the flow measurements and observations it was concluded that the areas covered by forest were less affected by the floods that occurred during heavy rainfalls than the areas covered by grass. Further on, the result of this report indicates that the Iracambi research station can continue to carry out assessments for changes in water flow, rainfall and evaporation with the simple equipment used in this project. However, more expensive and advanced equipment would be beneficial to establish a more accurate water balance. / Idag återstår endast 7% av den atlantiska regnskogen som en gång täckte Brasilien södra kust. Regnskogen försvinner snabbt vilket har lett till att Brasiliens regering de senaste åren visat ett ökat intresse att bevara regnskogen. Fler och fler områden har förvandlats till nationalparker och reservat. I utkanten till ett av dessa reservat ligger forskningsstationen Iracambi. Iracambi bedriver forskning i och runt området för att hitta metoder för att bevara regnskogen och öka kunskapen om området. Detta projekt är ett litet bidrag till detta arbete. Det övergripande syftet med projektet var att upprätta en vattenbalans över floden Graminhas avrinningsområde. Detta är huvudfloden i området och genom upprätta en vattenbalans kan förståelsen för förändringarna av vattentillgången i ekosystemet öka. Ett viktigt mål med projektet var också att finna verktyg som forskningsstationen Iracambi kan använda för kontinuerliga mätningar av de parametrar som ingår i vattenbalansen.Projektets genomfördes under regnperioden mellan den 13 februari och den 12 april, 2012. Flödesmätningarna utfördes vid fem mätstationer längs floden Graminha. Två typer av utrustning användes: flygel och konduktivitetsmätare. Rekommendationen för Iracambi var att fortsätta mätningarna med framförallt konduktivitetsmätaren. Uppskattningarna av avdunstningen genomfördes på två sätt: dels genom upprättandet av en evaporationspanna, dels genom beräkningar. Beräkningarna genomfördes med Penman-Monteith ekvationen och det kunde konstateras att även om de ingående parametrarna innehåller en del osäkerheter, så var detta den mest passande metoden för att beräkna avdunstningen. Nederbörd mättes på två platser med hjälp av enkla regnmätare konstruerade av pet-flaskor.Slutligen upprättades en vattenbalans för området. Utifrån denna kunde det konstateras att vattenmagasinet för hela orådet minskade under mätperioden. Utifrån flödesmätningar samt observationer kunde slutsatsen dras att skogsområdena drabbades mindre än de gräsbevuxna områdena av de kraftiga översvämningarna som uppstod under intensiva regn. Vidare visar resultaten att forskningsstationen Iracambi kan få en bra uppskattning av flödesförändringar, nederbörd och avdunstning med hjälp av den enkla utrustning som användes i detta projekt. / Minor Field Study

Made available in DSpace on 2014-06-11T19:31:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-10Bitstream added on 2014-06-13T20:01:24Z : No. of bitstreams: 1 oliveira_sms_dr_jabo.pdf: 285062 bytes, checksum: 2ff19f9c457a6961d50db465af94d58e (MD5) / Instituto Federal Triangulo Mineiro / A evapotranspiração de referência (ETo) é mais frequentemente obtida em diferentes situações e locais por meio de métodos de estimativa. A não verificação do erro da ETo, devido ao uso de instrumentos de medidas, pode conduzir os trabalhos de pesquisa a resultados não confiáveis e inconsistentes. Utilizando os Métodos de Hargreaves; Radiação Solar e Penman-Monteith, com os erros da ETo fixados em 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% e 10%, determinou-se as acurácias dos instrumentos de medidas necessárias para obter a estimativa da ETo, com os erros citados. Os dados foram coletados em uma Estação Meteorológica Automatizada, modelo Vaisala, da Usina Hidroelétrica de Nova Ponte, de propriedade da CEMIG, localizada no Rio Araguari. Estes valores foram registrados por meio da média diária de cada informação. A obtenção da ETo com erros propostos neste trabalho requer instrumentos de medidas com acurácias para os Métodos: de Hargreaves com temperatura do ar de 0,2645% a 2,6335% e radiação líquida de 0,0331% a 0,3315%; de radiação solar com temperatura do ar de 0,15% a 1,47%, velocidade do vento de 0,01% a 0,04%, umidade relativa do ar de 0,14% a 0,1,43% e radiação líquida de 0,02% a 0,23% e o de Penman-Monteith com Temperatura do ar de 0,33% a 3,2%, Velocidade do vento de 0,10% a 1,00%, de Umidade Relativa do ar de 0,06% a 0,58% e de Radiação Líquida entre 0,02% a 0,17%. As acurácias obtidas permitirão selecionar instrumentos de medidas para determinação da ETo, pelos métodos de Penman-Monteith, Hargreaves e Radiação Solar com erros máximos pré-estabelecidos. O método da Radiação Solar apresentou uma maior acurácia dos equipamentos meteorológicos utilizados em relação aos métodos PM (FAO 56) e Hargreaves / The reference evapotranspiration (ETo) is most often obtained in different situations and locations through estimation methods. The failure to find the error of ETo, due to the use of measuring instruments, can conduct research work to unreliable and inconsistent results. Using Hargreaves, Solar Radiation and Penman-Monteith methods, with ETo errors fixed in 1%, 2%, 3%, 4% ,5%, 6%, 7%, 8%, 9% and 10%, determined the accuracy of the instruments necessary to acquire the estimated ETo with the errors cited. The data were obtained in an Automated Weather Station, Vaisala model, of Nova Ponte Hydroelectric Plant, owned by Cemig, located in Araguari River. These values were recorded by the daily-average of each information. The attainment of ETo with errors proposed in this work requires measurement instruments with accuracies for the methods: Hargreaves with air temperature  0.2645% to  2.6335% and Net Radiation  0.0331% to  0, 3315% of solar radiation in air temperature  0.15% to 1.47%, wind speed  0.01% to 0.04%, Relative Humidity  0.14% of the  0,1,43% and Net Radiation  0.02% to  0.23% and the Penman-Monteith with air temperature  0.33% to 3.2%, wind speed  0 ,  10% to 1.00% RH air  0.06% to 0.58% and net radiation between  0.02% to 0.17%. The accuracy obtained will allow the selection of measurement instruments to determine the ETo by the Penman-Monteith, Hargreaves and Solar Radiation methods with pre-established maximum errors. The solar radiation method showned a greater accuracy of meteorological equipment used in the methods PM (FAO 56) and Hargreaves

The measurement of water in soil on a potential, gravimetric or volumetric basis is considered, with studies concentrating on the measurement of water by dielectric and neutron moderation methods. The ability of the time-domain reflectometry technique to measure water content simultaneously at different spatial locations is an important advantage of the technique. The reported apparent dielectric by the TRASE� time-domain reflectometer and Pyelab time-domain reflectometry systems is sensitive to change in extension cable length. In some soil, e.g. a commercial sand, the response to increasing extension length of extension cable is linear. For other soil a linear response occurs for certain lengths of cable at different moisture contents. A single model accounting for clay content, extension cable length, time-domain reflectometry system, probe type and inherent moisture conditions explained 62.2 % of variation from the control (0 m extension) cable. The extension cable causes a decrease in the returning electromagnetic-wave energy; leading to a decline in the slope used in automatic end-point determination. Calibration for each probe installation when the soil is saturated, and at small water contents is recommended. The ability of time-domain reflectometry, frequency-domain and neutron moderation techniques in measuring soil water content in a Brown Chromosol is examined. An in situ calibration, across a limited range of water contents, for the neutron moderation method is more sensitive to changing soil water content than the factory supplied 'universal' calibration. Comparison of the EnviroSCAN� frequency-domain system and the NMM count ratio indicates the frequency-domain technique is more sensitive to change in soil water conditions. The EnviroSCAN� system is well suited to continuous profile-based measurement of soil water content. Results with the time-domain reflectometry technique were disappointing, indicating the limited applicability of time-domain reflectometry in profile based soil water content measurement in heavy-textured soil, or soil with a large electrical conductivity. The method of auguring to a known depth and placement of the time-domain reflectometry probe into undisturbed soil is not recommended. A time-domain reflectometry system is adapted for in situ measurement of water in an iron ore stockpile. The laboratory calibration for water content of the processed iron ore compares favourably to a field calibration. In the field study, the 28 m extension cable used to connect the probes to the time-domain reflectometry affected the end-point determination of the time-domain reflectometry system. To account for this, 0.197 should be subtracted from the reported apparent dielectric before calculation of volumetric moisture content.

The estimation of evapotranspiration (ET), a key process within the Earth's surface water and energy balance, remains an important challenge for a wide range of disciplines such as surface hydrology, irrigation management and meteorology. However, notwithstanding the considerable progress recently made in our understanding of the physical and biological processes governing ET, the accurate quantification of ET is very tricky to achieve, even at a limited spatial scale. In this study, we combine field measurements with numerical experiments to tackle issues related to the quantification of ET and the associated uncertainties for a maize cropped field using two different approaches, i.e. the agro-hydrological modelling and the soil water balance approach. For the agro-hydrological modelling, we mainly focus on the estimation of field-scale soil water content and on the identification of root water uptake parameters. With regard to the field-scale soil water content, we put forward that the within-field variability is large and that the maize crop plays a non-negligible role in the development of the soil water content patterns both at the field and at the maize row scale. For deriving root water uptake parameters (RWUP), we develop and test two different approaches, i.e. the simplified soil water balance and the inverse modelling approach. Using numerical experiments, we show that the simplified soil water balance approach produces quite accurate RWUP. On the other hand, the inverse modelling approach is only successful for some soils and for some conditions due to instability and nonuniqueness issues. For the soil water balance approach, we show that the accuracy of the local ET estimate is strongly dependent on the estimation method used to derive the bottom fluxes and that the use of pedotransfer functions is of little interest. For field-scale ET estimates, we show that the variability of ET is large both at the field scale (due to the variable crop growth) and at the maize row scale (due to the maize row layout). To produce accurate field-scale ET estimates, we suggest to scale up maize row scale ET estimates using the concept of temporal stability or using a covariant such as the Leaf Area Index. The results of our study suggest that the estimation of water fluxes or associated state variables for a row cropped field requires a two-step upscaling strategy, from the local scale to the row, then from the row to the field scale.

The boreal forest forms a band that stretches across the continents of the northern hemisphere. Wildfire disturbances have helped transform this forest into stands of varying ages with varying soil drainage. It is well known that the boreal forest contributes greatly to the global water cycle, but less is known as to how variable these water fluxes are throughout the forest mosaic. Throughout the growing seasons of 2006 and 2007, meteorological measurements were taken during the growing season from three different aged black spruce stands near Thompson, MB. The stands that were burned in 1930 and 1964 each included upland and lowland sites with independent measurements. The stand burned in 1850 had measurements taken only from an upland site. Evapotranspiration (ET) was calculated from the residual energy after net radiation (Rn), sensible heat flux (H) and ground heat flux were measured. We sought to investigate whether ET varied with stand age and topographic location. Results indicate that there is a significant increase in Rn, H, and ET as forests age. ET levels range from being 4% to 19% lower for younger stands. It is assumed that the depth of the organic layer at older sites allows for mosses to more effectively wick up available moisture through capillary rise, and have higher transpiration levels. The larger tree density at the 1964 sites compared to the 1930 sites may account for a portion of the observed increase in ET for these ages. Differences in drainage between the 1930 and 1850 sites may also account for a portion of the increase in ET observed between these two ages. Wetland sites had H and ET that were significantly less than for the upland sites. ET rates were 11 to 20% higher at the upland sites than the wetland sites; part of this difference is thought to be due to the presence of larger trees, with an increased capacity to transpire water at upland sites. As the number of forest fires has been predicted to increase substantially in the future, the prospect of the boreal forest average stand age being younger would affect the boreal’s water and energy budgets. Our data helps to describe water and energy budgets for forest stands with different drainage capabilities, for stands between the ages of 45 and 160 years. This knowledge will be used to help predict the degree and speed of climate change that will be experienced in the boreal forest. / October 2008

This project was performed at Rochester Institute of Technology to get more understanding and knowledge about AM and FM screenings similarities and differences with considerations of the mottle. By designing a test form conformed to the specific measurements and printing it on Heidelberg's Sunday 2000 press, the project group has evaluated the questions that already existed and the ones that occurred during the project. Hence the first press run left some unexpected phenomenon therefore another press run was performed. Measurements were performed and graphs produced in Excel. The project group evaluated the results and from that able to establish facts and draw conclusions. It has been a great experience for the project group and they have learnt a lot.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.