Hydrogeological-Geophysical Methods for Subsurface Site Characterization

本项目重点关注污染场地环境管理的三个关键问题：降低成本、降低风险和提高地下修复方案的有效性。这项建议的意义在于它解决了场地特征的问题：这个问题不仅是场地清理工作中非常重要的预算项目，而且现在人们认识到，准确可靠的场地特征是任何清理工作成功的关键。我们的目标是为自然非均质性的低成本高分辨率成像，以及将这些非均质性与控制流量和污染物运移的水文地质参数联系起来，开发“成像”水文地质参数的方法，发展科学基础和示范方法。我们的重点是通过(a)可行性研究，(b)沉积岩物理学，以及(c)改进地球物理和水文地质数据共同解释的程序，帮助建立将浅层地球物理应用于水文地质问题的科学基础。一项重要的任务将是识别这些共同解释的局限性、陷阱和不确定性。，以量化将浅层地球物理应用于水文地质地点表征的风险。该方案结合了理论建模、实验室测量分析和集成技术。我们的方法是联合使用地震和电磁方法来绘制由一组井眼定义的三维体中的地震速度、衰减和电导率分布。粗略地说，速度和导电性都取决于孔隙度，在较小程度上取决于渗透率、粘土含量、饱和度和孔隙流体性质。实验室研究已经非常详细地显示了这些关系，我们现在建议改进这些结果，利用它们来解释水文地质性质分布图方面的调查数据。本课题综合了水文地质与地质统计学、地球物理、岩石物理等学科，是一项跨学科的研究。研究人员团队为这个项目带来了大量的理论、实地和实验室工作的集体经验。为了应对原始预算的削减，我们减少了实验室测试的范围和我们将在可行性研究中调查的各种地质环境。？?

9628306 Yoram Rubin This project focuses on three issues that are critical to environmental management of contaminated sites: reducing cost, reducing risk, and increasing the effectiveness of subsurface remediation schemes. The significance of this proposal is that it addresses the issue of site characterization: not only that this issue is a very significant budget item in the site cleanup effort, but also it is now realized that accurate and reliable site characterization is the key to the success of any cleanup effort. Our objective is to develop the scientific basis and demonstrate methodologies for inexpensive high resolution imaging of natural heterogeneities and for relating these heterogeneities to the hydrogeologic parameters that control flow and contaminant transport--in effect, to develop methods for "imaging" hydrogeologic parameters. Our focus is to help establish the scientific basis for applying shallow geophysics to hydrogeological problems, through (a) feasibility studies, (b) sediment-rock physics, and (c) improvements in the procedures for co-interpretation of geophysical and hydrogeological data. An essential task will be to identify limitations, pitfalls, and uncertainties of these co-interpretation--i.e., to quantify the risks in applying shallow geophysics to hydrogeological site characterization. The proposal combines theoretical modeling, analysis of laboratory measurements, and integration techniques. Our approach is to use seismic and electromagnetic methods jointly to map the distribution to seismic velocity and attenuation and electrical conductivity in the the 3-D volume defined by a set of boreholes. In a rough sense, both velocity and conductivity depend on porosity and to a lesser extent on permeability, clay content, saturation and nature of pore fluid. Laboratory studies have shown these relationships in great detail and we now propose to refine these results to utilize them to interpret survey data in terms of map of the distribution of t he hydrogeologic properties. This proposal is an interdisciplinary study, since it integrates the fields of hydrogeology and geostatistics, geophysics, and rock physics. The team of researchers brings to this project a large collective experience in performing theoretical, field, and lab work. In response to cuts in the original budget, we reduced the scope of lab testing and the variety of geological setting that we shall investigate under Feasibility Studies. ??