Water redistribution and the fate and transport of chemicals in nonlevel landscapes

非平面景观中水的再分配以及化学物质的归宿和运输

• 批准号: 238444-2010
• 负责人: Si, BingCheng
• 金额: $ 2.55万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=524335
• 关键词: Water; redistribution; fate; transport; chemicals

Soil water is a key variable in crop production, flooding, runoff, and greenhouse gas emission from soils. Also affected are the fate and transport of agrochemicals or wastes, via runoff to surface water, leading to groundwater, emission to the atmosphere, or uptake by plants. Canadian prairies landscapes are not level, which will change water pathways and increase both spatial and temporal variability of soil water. The long term objective to this work is to quantify, and develop theories to predict soil water dynamics and the fate of chemicals in non-level landscapes. In the short term, the objectives and the research approach will be to (1) develop single probe, and cylindrical probe heat pulse methods for measuring thermal properties and soil water content; (2) measure soil water content and thermal properties over the landscape scales using the distributed temperature sensor; (3) quantify the dominant controls of soil water and thermal dynamics at the pedon, slope, and landscape scales. Soil water content will be measured along a transect in a landscape. The spatial variation of and scaling relationships between soil water, root water uptake, and the topography will be evaluated and dominant scales of variation be identified; and (4) develop and validate models for soil water and thermal dynamics under different vegetation covers, and soil properties and topographies. Based on objective 3, a model taking into account of intermittent rainfall infiltration will be developed, and will then be used as a tool for predicting the general trend in soil water dynamics on a hillslope and at a landscape scale. The knowledge gained through this study will further the understanding of the landscape hydrology, and eventually the soil water dynamics in ecosystems. The latter will be useful for quantifying plant succession, biodiversity, and water quality in semi-arid environments.

土壤水分是作物生产、洪水、径流和土壤温室气体排放的关键变量。也受到影响的还有农用化学品或废物的去向和运输，通过径流进入地表水，导致地下水，排放到大气，或被植物吸收。加拿大草原地貌不平坦，这将改变水路，增加土壤水分的空间和时间变异性。这项工作的长期目标是量化和发展理论，以预测土壤水动态和非水平景观中化学物质的命运。在短期内，目标和研究方法将是：(1)开发单探头和圆柱形探头热脉冲方法来测量热特性和土壤水分含量；(2)利用分布式温度传感器测量景观尺度上的土壤水分和热特性；(3)在土壤、坡度和景观尺度上量化土壤水和热动力的主要控制因素。土壤水分将沿着景观中的一条横断面进行测量。将评估土壤水分、根系吸水量和地形之间的空间变异和尺度关系，并确定变异的主要尺度；以及(4)开发和验证不同植被覆盖、土壤性质和地形下的土壤水热动态模型。在目标3的基础上，将建立一个考虑间歇性降雨入渗的模型，并将其用作预测坡面和景观尺度上土壤水分动态的一般趋势的工具。通过这项研究所获得的知识将进一步加深对景观水文学的理解，并最终加深对生态系统中土壤水动力学的了解。后者将有助于量化半干旱环境中的植物演替、生物多样性和水质。