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: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=454922
• 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.

土壤水是作物生产、洪水、径流和土壤温室气体排放的关键变量。农用化学品或废物的归宿和运输也受到影响，通过径流进入地表水，导致地下水、排放到大气中或被植物吸收。加拿大大草原景观不平坦，这将改变水的路径并增加土壤水的空间和时间变化。这项工作的长期目标是量化和发展理论来预测土壤水动态和非水平景观中化学物质的命运。短期内，目标和研究方法将是（1）开发用于测量热性质和土壤含水量的单探头和圆柱形探头热脉冲方法； (2)利用分布式温度传感器测量景观尺度的土壤含水量和热特性； （3）量化土壤水和热动力学在土壤、坡度和景观尺度上的主导控制。将沿着景观中的样线测量土壤含水量。将评估土壤水、根系吸水量和地形之间的空间变化和尺度关系，并确定变化的主要尺度； (4) 开发并验证不同植被覆盖、土壤性质和地形下的土壤水和热动力学模型。基于目标 3，将开发一个考虑间歇性降雨入渗的模型，然后将其用作预测山坡和景观尺度土壤水动态总体趋势的工具。通过这项研究获得的知识将进一步了解景观水文学，并最终了解生态系统中的土壤水动态。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。