Made available in DSpace on 2015-03-26T13:32:12Z (GMT). No. of bitstreams: 1 texto completo.pdf: 500078 bytes, checksum: 214f761ce3ebbbbfdafedbd488eff22d (MD5) Previous issue date: 2011-07-25 / This study evaluated, through data simulation, the performance of fractional factorial designs of resolutions III, IV and V, the design of Cotter (1979) and UFPV method to estimate the main effects of the factors studied on an answer, presence or absence of only double interactions between them. For this, we estimated the main effects of three, four, five and ten factors with two levels. In the study of three factors, the main effects were estimated by the factorial and the UFPV. In order to study the four factors, the main effects were estimated by the fractional factorial, the UFPV and the design of Cotter (1979). For five factors were estimated by the main effects fractional factorial and at UFPV and the design of Cotter (1979). For the study of the ten factors, the main effects were estimated by the fractional factorial and at UFPV and the design of Cotter (1979). In all cases, 100 simulations were performed. To evaluate the performance of proposed designs, the main effects were estimated and applied separately for each situation, the Student t test for an average of 5% probability with 100 repetitions, according to the following hypothesis: Ho: p = parameter defined for each main effect separately. After analyzing the results, it was concluded that under the double presence of interactions, the fractional factorial resolution III UFPV and the method should not be used. Since the fractional factorial designs of resolutions IV and V and the design of Cotter (1979) study were satisfactory for three, four, five and ten factors, with or without the presence of double interactions. / O presente trabalho avaliou, por meio da simulação de dados, os desempenhos dos fatoriais fracionados de resoluções III, IV e V, do delineamento de Cotter (1979) e do método UFPV, para estimar os efeitos principais dos fatores estudados sobre uma resposta, na presença ou não de apenas interações duplas entre eles. Para tanto, foram estimados os efeitos principais de três, quatro, cinco e dez fatores com dois níveis. No estudo de três fatores, foram estimados os efeitos principais pelo fatorial e pelo UFPV. Para estudar os quatro fatores, os efeitos principais foram estimados pelo fatorial fracionado, pelo UFPV e pelo delineamento de Cotter (1979). Para cinco fatores foram estimados os efeitos principais pelos fatoriais fracionados, pelo UFPV e pelo delineamento de Cotter (1979). Para o estudo dos dez fatores, os efeitos principais foram estimados pelos fatoriais fracionados, pelo UFPV e pelo delineamento de Cotter (1979). Em todos os casos foram realizadas 100 simulações. Para avaliar o desempenho dos delineamentos propostos, foram estimados os efeitos principais e aplicado, para cada situação separadamente, o teste t de Student para uma média a 5% de probabilidade com 100 repetições, de acordo com a seguinte hipótese: Ho: ep = parâmetro definido para cada efeito principal, separadamente. Após a análise dos resultados, concluiu-se que sob a presença das interações duplas, o fatorial fracionado de resolução III e o método UFPV não devem ser utilizados. Já os fatoriais fracionados de resoluções IV e V e o delineamento de Cotter (1979) foram satisfatórios para estudarem três, quatro, cinco e dez fatores, sem ou com a presença das interações duplas.

Existing terrestrial carbon accounting models have mainly investigated atmosphere-vegetationsoil stocks and fluxes but have largely ignored the hydrological flux of organic carbon. It is generally assumed that biomass and soil carbon are the only relevant pools in a landscape ecosystem. However, recent findings have suggested that significant amounts of organic carbon can dissolve (dissolved organic carbon or DOC) or particulate (particulate organic carbon or POC) in water and enter the hydrological flux at the catchment scale. A significant quantity of total organic carbon (TOC) sequestered through photosynthesis may be exported from the landscape through the hydrological flux and stored in downstream stocks.¶ This thesis presents a catchment-scale case study investigation into the export of organic carbon through a river system in comparison with carbon that is produced by vegetation through photosynthesis. The Cotter River Catchment was selected as the case study. It is a forested catchment that experienced a major wildfire event in January 2003. The approach is based on an integration of a number of models. The main input data were time series of in-stream carbon measurements and remotely sensed vegetation greenness. The application of models to investigate diffuse chemical substances has dramatically increased in the past few years because of the significant role of hydrology in controlling ecosystem exchange. The research firstly discusses the use of a hydrological simulation model (IHACRES) to analyse organic carbon samples from stream and tributaries in the Cotter River Catchment case study. The IHACRES rainfall-runoff model and a regionalization method are used to estimate stream-flow for the 75 sub-catchments. The simulated streamflow data were used to calculate organic carbon loads from concentrations sampled at five locations in the catchment.¶ The gross primary productivity (GPP) of the vegetation cover in the catchment was estimated using a radiation use efficiency (RUE) model driven by MODIS TERRA data on vegetation greenness and modeled surface irradiance (RS). The relationship between total organic carbon discharged in-stream and total carbon uptake by plants was assessed using a cross-correlation analysis.¶ The IHACRES rainfall-runoff model was successfully calibrated at three gauged sites and performed well. The results of the calibration procedure were used in the regionalization method that enabled streamflow to be estimated at ungauged locations including the seven sampling sites and the 75 sub-catchment areas. The IHACRES modelling approach was found appropriate for investigating a wide range of issues related to the hydrological export of organic carbon at the catchment scale. A weekly sampling program was implemented to provide estimates of TOC, DOC and POC concentrations in the Cotter River Catchment between July 2003 and June 2004. The organic carbon load was estimated using an averaging method.¶ The rate of photosynthesis by vegetation (GPP) was successfully estimated using the radiation use efficiency model to discern general patterns of vegetation productivity at sub-catchment scales. This analysis required detailed spatial resolution of the GPP across the entire catchment area (comprising 75 sub-catchment areas) in addition to the sampling locations. Important factors that varied at the catchment scale during the sampling period July 2003 – June 2004, particularly the wildfire impacts, were also considered in this assessment. ¶ The results of the hydrologic modelling approach and terrestrial GPP outcome were compared using cross correlation and regression analysis. This comparison revealed the likely proportion of catchment GPP that contributes to in-stream hydrological flux of organic carbon. TOC Load was 0.45% of GPP and 22.5 - 25% of litter layer. As a result of this investigation and giving due consideration to the uncertainties in the approach, it can be concluded that the hydrological flux of organic carbon in a forested catchment is a function of gross primary productivity.