Hettiaratchi, Joseph Patrick A.Jalilzadeh, Hiva2019-09-182019-09-182019-09-16Jalilzadeh, H. (2019). Field Performance and Water Balance Predictions of Evapotranspirative Landfill Biocovers (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/111000The present research aims to extend the application of Evapotranspirative (ET) covers to Canadian landfill biocovers and assess their performance under climatic conditions present in Canada. Seven large-scale lysimeters were constructed simulating a capillary barrier landfill biocover and monitored for water balance from May 2018 to May 2019. Two soil types (Topsoil and Compost mixture) and three types of vegetation (Native grass species, Alfalfa, and Japanese Millet) were used to investigate the most effective design. Rainfall simulations were carried out to assess the performance of vegetated and non-vegetated covers. Water balance predictions made using two codes (SEEP/W and HYDRUS) were compared to water balance data from lysimeters over the growing season. The rainfall simulation results suggested that the compost mixture was able to hold 40 % more moisture than topsoil, on average. Percolation as a percentage of rainfall (percolation percentage) was significantly lower for vegetated media compared to bare or poorly vegetated media. During the growing season, Alfalfa had the highest average ET rate, followed by Japanese Millet and Native grass species. Among soil, plant and meteorological factors, solar radiation, surface cover fraction, rooting depth and plant height had a significant effect on ET rates. The results suggested that as plants became established, the average percolation percentage decreased for all crop types. Annual percolation percentage was 13-14 % for lysimeters which were not subjected to rainfall simulations. Among lysimeters subjected to rainfall simulations, lysimeters with Japanese Millet transmitted the lowest amount of percolation (10 %-17 %), followed by Native Grass species and Alfalfa (23 %-28 %). Under the same vegetation coverage, lysimeters with compost mixture generally transmitted lower or equal percolation compared to lysimeters with topsoil. Modelling results from June 2018 to September 2018 (110 days) showed that predicted evapotranspiration was in better agreement with field results when the Penman-Monteith (PM) method was used instead of Penman-Wilson (PW). In general, soil water storage and percolation were overpredicted by both codes using the PM method and underpredicted using the PW method. Model limitations included predictions under high-intensity rainfall events, estimating canopy interception and considering preferential pathways associated with plant roots.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.EvapotranspirationLandfillBiocoverWater balanceartificial rainfallrainfall simulationalfalfavegetative covercapillary barrierunsaturated soilSEEP/WHYDRUSroot water uptakemethanotrophyEngineering--CivilEngineering--Environmentalmaster thesishttp://dx.doi.org/10.11575/PRISM/37065