Advancements in computation and development of physically based hydrologic models to simulate complex vadose zone scenarios helped the research community to evaluate different scenarios easily compared to long-term field experiments. However, some field data collection is necessary to obtain input data such as soil properties, water usage and land management practices to validate the model performance specific to the site. Data obtained from field experiments conducted in 2011 at Hespler farms, Winkler, MB was used in this research for model calibration and validation. The hydrologic model, HYDRUS (2D/3D) was evaluated using parameters such as visual and statistical analysis. Model evaluation during the calibration and validation stage gave RMSE values of 0.019 and 0.015 cm3 cm-3; PBIAS values of -1.01 and -0.14, respectively, suggesting that the model was efficient in simulating soil water content similar to the field observed data. The validated models were then used to simulate outcomes for different scenarios such as 30-year rainfall data (1986 – 2015), different soil physical properties, and drainage system design parameters. Models simulating free drainage predicted lower soil water content compared to controlled drainage leading to 6 – 60 more trafficable days for 8 m spacing and 0.9 drain base depth. Free drainage predicted 8 – 110 additional trafficable days compared to controlled drainage for 15 m spacing and 1.1 drain depth. Heavier than normal rainfall events caused high water contents leading to a few years with a very low to no trafficable days under controlled drainage conditions. The comparisons are presented based on models using free drain conditions. Models with 8-m drain spacing predicted a 1 to 10-day increase in the number of trafficable days compared to the 15-m drain spacing. Drains placed at a base depth of 1.1 m below the soil surface predicted 4 - 40 more trafficable days compared to those installed at a base depth of 0.9 m. / October 2017

Made available in DSpace on 2016-06-02T20:00:55Z (GMT). No. of bitstreams: 1 5728.pdf: 4886967 bytes, checksum: 9a66021bc6eec94037ca58204cb8fb84 (MD5) Previous issue date: 2013-08-23 / Financiadora de Estudos e Projetos / Stormwater flooding in urban centers today is the direct result of ground impermeabilization and the ineffective dimensioning of stormwater drainage systems. In order to control these events, innovative low impact stormwater drainage facilities are used in Brazil, which are efficient in controlling sharp peak flows in urban watersheds without, however, affecting the aesthetic appearance of the landscape in these environments. The purpose of this study is to model and estimate the volume of water infiltrated into the soil where a compensatory stormwater drainage system is inserted, which can contribute to groundwater recharge. Modeling was performed by means of a physical storage method and storage variation in soil using a tensiometer, and in digital form using the Hydrus 2D/3D software package. The monitored drainage system and the digitally designed system consist of a water retention basin, a ditch or filter, and an infiltration trench. Groundwater recharge was estimated based on soil analyses, geophysical investigations, flow measurements, and rainfall data, in addition to data collected during 454 days of continuous monitoring of the system by means of tensiometers installed on-site, rain gauges, and the construction of bimodal soil water retention curves using the filter paper method. The moisture content at different depths, the zero water flow plane, and the volumes moving in the soil matrix were calculated based on the identification of the soil water content and matric potential, the hydraulic conductivity in saturated conditions at the monitored depths, and the soil s characteristic curves. The results of the Soil Water Retention Curves (SWRC) and soil moisture content were negligible starting from a depth of 80cm. However, the groundwater recharge rate estimated by the tensiometer method and by the Hydrus digital model was about 45% of the total volume of rainfall. / Atualmente, eventuais problemas de enchentes e inundações, são causas diretas da impermeabilização de áreas nos centros urbanos e do ineficaz dimensionamento da drenagem pluvial nas cidades. No intuito de se controlar estes eventos, equipamentos de drenagem de baixo impacto são inovadoras no Brasil e eficientes no controle de vazões de pico acentuadas em bacias urbanas, sem sobretudo, renunciar à estética e à paisagem nestes ambientes. Neste trabalho objetivou-se modelar e estimar o volume de água infiltrado no solo, onde um sistema de drenagem pluvial compensatória está inserido, que é capaz de contribuir com a recarga freática. A modelagem foi realizada por meio do método de armazenamento e variação da armazenagem no solo com utilização de tensiômetro e de forma digital utilizando-se do software Hydrus 2D/3D. O sistema de drenagem monitorado e o diagramado digitalmente são constituídos de uma bacia de retenção de água, uma vala ou filtro gramado e uma trincheira de infiltração. Na tentativa de estimar a recarga freática realizaram-se, conjuntamente, análises de solo, investigações geofísicas, medidas de vazão, coleta de dados de chuva, além do monitoramento contínuo em 454 dias do sistema através da instalação de tensiômetros no local, pluviógrafos, além da construção de curvas bimodais de retenção de água nos solos por meio do método do papel filtro. A partir da identificação dos potenciais mátricos do solo, da condutividade hidráulica em condições saturadas para as profundidades monitoradas e da obtenção das curvas características do solo, foi possível calcular o teor de umidade em diferentes profundidades, identificar o plano de fluxo zero e calcular os volumes em movimento na matriz do solo. Os resultados obtidos pela verificação das Curvas de Retenção de Água no Solo (CRAs) e umidades de campo foram pouco expressivos a partir de 80cm de profundidade, entretanto, a recarga estimada obtida pelo método dos tensiômetros e pelo modelo digital Hydrus ficou em torno de um valor médio de 45% do volume total precipitado.