School of Environment and Technology, University of Brighton, Lewes Road, Brighton BN2 4GJ, UK.
J Environ Manage. 2013 Nov 15;129:628-34. doi: 10.1016/j.jenvman.2013.08.030. Epub 2013 Sep 13.
Improvements in computing speed and capacity and the increasing collection and digitisation of geological data now allow geoscientists to produce meaningful 3D spatial models of the shallow subsurface in many large urban areas, to predict ground conditions and reduce risk and uncertainty in urban planning. It is not yet clear how useful this 3D modelling approach is at smaller urban scales, where poorly characterised anthropogenic deposits (artificial/made ground and fill) form the dominant subsurface material and where the availability of borehole and other geological data is less comprehensive. This is important as it is these smaller urban sites, with complex site history, which frequently form the focus of urban regeneration and redevelopment schemes. This paper examines the extent to which the 3D modelling approach previously utilised at large urban scales can be extended to smaller less well-characterised urban sites, using a historic landfill site in Sheepcote Valley, Brighton, UK as a case study. Two 3D models were generated and compared using GSI3D™ software, one using borehole data only, one combining borehole data with local geological maps and results from a desk study (involving collation of available site data, including ground contour plans). These models clearly delimit the overall subsurface geology at the site, and allow visualisation and modelling of the anthropogenic deposits present. Shallow geophysical data collected from the site partially validate the 3D modelled data, and can improve GSI3D™ outputs where boundaries of anthropogenic deposits may not be clearly defined by surface, contour or borehole data. Attribution of geotechnical and geochemical properties to the 3D model is problematic without intrusive investigations and sampling. However, combining available borehole data, shallow geophysical methods and site histories may allow attribution of generic fill properties, and consequent reduction of urban development risk and uncertainty.
计算速度和容量的提高，以及地质数据的不断收集和数字化，现在使地球科学家能够在许多大城市地区生成有意义的浅层地下 3D 空间模型，预测地面条件，降低城市规划中的风险和不确定性。目前尚不清楚这种 3D 建模方法在较小的城市规模上有多有用，在这些规模较小的城市中，特征较差的人为沉积物（人工/造地和填土）构成了主要的地下物质，并且钻孔和其他地质数据的可用性不太全面。这很重要，因为正是这些具有复杂场地历史的较小城市场地，经常成为城市再生和再开发计划的焦点。本文以英国布莱顿的 Sheepcote Valley 历史垃圾填埋场为例，研究了在较小、特征较差的城市场地中，以前在较大城市规模上使用的 3D 建模方法在多大程度上可以扩展。使用 GSI3D™软件生成并比较了两个 3D 模型，一个仅使用钻孔数据，另一个将钻孔数据与局部地质图和桌面研究的结果（包括可用场地数据的整理，包括地面等高线图）相结合。这些模型清楚地划定了该场地的整体地下地质，并允许对存在的人为沉积物进行可视化和建模。从该场地收集的浅层地球物理数据部分验证了 3D 模型化数据，并且可以在人为沉积物的边界可能无法通过表面、等高线或钻孔数据清楚地定义的情况下，改善 GSI3D™的输出。如果没有侵入性调查和采样，将岩土和地球化学特性归因于 3D 模型是有问题的。但是，结合可用的钻孔数据、浅层地球物理方法和场地历史记录，可能可以对通用填土特性进行归因，并相应降低城市发展的风险和不确定性。
