COLLABORATIVE RESEARCH: Evaluating Long-Term Impacts on Final Covers -- Exhumation of the ACAP Test Sections

合作研究：评估对最终封面的长期影响——ACAP 测试部分的挖掘

• 批准号: 0625850
• 负责人: Craig Benson
• 金额: --
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0625850&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Evaluating; Long; Term

Abstract The objective of this study is to evaluate the effects of pedogenesis on the properties of soils and geosynthetics in landfill final covers and the mechanisms that control pedogenic changes. This objective will be met by conducting physical experiments while exhuming large-scale test sections simulating final covers that were constructed in 1999-2000 for the Alternative Cover Assessment Program (ACAP). Field hydraulic conductivity tests will be conducted on each test section to identify the magnitude and variability in saturated hydraulic conductivity, and dye and salt tracer tests will be conducted to assess preferential flow. Data from these tests will be analyzed with a variably saturated flow and transport model that accounts for coupling between the matrix and preferential flow paths, and using data collected regarding state variables (matric suction, water content, temperature, etc.). Large block samples will be removed from each test section at various locations and depths and tested to evaluate how the hydraulic properties vary spatially and with scale. Geomorphic mapping will be conducted to provide quantitative information on soil structure that can be used to interpret the magnitude and scale-dependence of changes in hydraulic properties. Vegetation surveys will be conducted to evaluate transitions in species distribution, rooting depth and density, and other characteristics affecting transpiration, and to assess whether transitions are coupled to pedogenesis. The results will be used to identify physical, hydrological, and biological mechanisms that affect cover performance and to provide insight into how covers change over time. The lessons learned will be used to improve cover design and construction and for assessments of long-term performance. The findings will also apply to other hydrologic problems (e.g., natural recharge, urban watershed hydrology, infiltration and runoff in engineered landscapes). Additional broader impacts will be obtained by enhanced student learning via inter-disciplinary and inter-institutional collaboration, development of a hydrology module for a middle school environmental science curriculum, and by recruiting diversity students to the project.

摘要本研究旨在探讨成土作用对垃圾填埋场终盖层土壤和土工合成物性质的影响，以及控制成土作用变化的机制。这一目标将通过进行物理实验来实现，同时挖掘1999-2000年为替代覆盖评估计划（ACAP）建造的模拟最终覆盖的大型测试部分。将对每个测试段进行现场水力导电性测试，以确定饱和水力导电性的大小和变化，并进行染料和盐示踪剂测试，以评估优先流动。这些试验的数据将使用可变饱和流动和输运模型进行分析，该模型考虑了基质和优先流动路径之间的耦合，并使用关于状态变量（基质吸力、含水量、温度等）收集的数据。将从每个测试段的不同位置和深度取出大块样品，并进行测试，以评估水力性能在空间和尺度上的变化。地貌测绘将提供土壤结构的定量信息，这些信息可用于解释水力特性变化的幅度和尺度依赖性。植被调查将评估物种分布、生根深度和密度以及其他影响蒸腾的特征的转变，并评估这些转变是否与土壤形成有关。研究结果将用于确定影响覆盖性能的物理、水文和生物机制，并深入了解覆盖如何随时间变化。吸取的经验教训将用于改进掩体的设计和建造，并用于评估长期业绩。研究结果也将适用于其他水文问题（例如，自然补给、城市流域水文学、工程景观中的渗透和径流）。通过跨学科和机构间的合作促进学生的学习，为中学环境科学课程开发水文学模块，以及招募多元化的学生参加该项目，将会产生更广泛的影响。