Mechanics of soil erosion by water: Mathematical modelling and laboratory experimentation

水土流失机理：数学模型和实验室实验

• 批准号: RGPIN-2020-06271
• 负责人: Gumiere, Silvio
• 金额: $ 1.89万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741128
• 关键词: Mechanics; soil; erosion; water; Mathematical

Soil erosion by water is foremost to an accelerated loss of the world's food-producing lands, threatening global food security and water quality. Soil erosion is increasing as a result of long-term human-related activities and its erosion-prone landforms and climate change. The FAO led Global Soil Partnership reports that 75 billion tonnes per year of soil are eroded from arable lands worldwide. Anthropogenic forces that alter the physical landscape cause substantial soil erosion, which harms surface water bodies and therefore necessitating sediment control as essential aspects of catchment management planning. Simulation models are a vital component of attempts to understand the impact of agricultural processes, land-use and climate change on soil erosion. However, nowadays approaches to modelling soil erosion, despite an endless number of available models, have shown little overall improvement in their ability to predict erosion processes. Due to the complexity, multiple scales and time dependence erosion processes are hard to be thoroughly characterized. That is why most of the nowadays models are only based on soil loss experiments in steady-state conditions, with constant-intensity rainfall rater then phenomenological ones. What makes predictive models very limited to the date and soil types they were calibrated The proposed research program is designed to gain deeper insights into the fine-scale physical mechanisms governing soil erosion using cutting edge experimental technics and new modelling frameworks. The uniqueness of this research program lies in the integrated analysis of hydrological and soil conditions (initial and boundary) and subsequent effects on contaminant transport. More specifically, the short-term objectives of the present research program are to develop: (i) high-speed, high-resolution imaging and CT-Scan techniques to simultaneously track sediment particles in shallow overland flow under controlled laboratory conditions; (ii) a very detailed discrete element model associated with the Lattice Boltzmann method (LBM) of the main processes governing soil detachment and transport by water and (iii)a modified version of the model for field and research applications in the form of a WEB-based version for field and research applications, decision maker's, agronomists and engineers.

水土流失是导致世界粮食生产土地加速流失的首要因素，威胁着全球粮食安全和水质。由于长期的人类活动及其易受侵蚀的地貌和气候变化，土壤侵蚀正在加剧。粮农组织领导的全球土壤伙伴关系报告称，全世界每年有 750 亿吨土壤被耕地侵蚀。改变自然景观的人为力量会导致严重的土壤侵蚀，从而损害地表水体，因此需要将沉积物控制作为流域管理规划的重要方面。模拟模型是了解农业过程、土地利用和气候变化对土壤侵蚀影响的重要组成部分。然而，当今的土壤侵蚀建模方法，尽管有无数可用的模型，但在预测侵蚀过程的能力方面几乎没有显示出总体改进。由于复杂性，多尺度和时间依赖性侵蚀过程很难彻底表征。这就是为什么现在大多数模型仅基于稳态条件下的土壤流失实验，采用恒强降雨率，然后是现象学模型。是什么使得预测模型非常局限于校准的日期和土壤类型拟议的研究计划旨在利用尖端实验技术和新的建模框架更深入地了解控制土壤侵蚀的精细物理机制。该研究项目的独特性在于对水文和土壤条件（初始和边界）以及污染物迁移的后续影响进行综合分析。更具体地说，本研究计划的短期目标是开发：（i）高速、高分辨率成像和 CT 扫描技术，以在受控实验室条件下同时跟踪浅层地表流中的沉积物颗粒； (ii) 与控制土壤分离和水运移的主要过程的格子玻尔兹曼方法 (LBM) 相关的非常详细的离散元模型，以及 (iii) 以 WEB 形式用于现场和研究应用的模型的修改版本适合现场和研究应用、决策者、农学家和工程师的版本。