The ability to identify, at potential managed aquifer recharge sites, the presence of connected pathways of hydraulically conductive sediments from the ground surface to the water table could help minimize costs and risks associated with recharge operations. A spatially dense dataset had previously been acquired in an almond [Prunus dulcis (Mill.) D.A. Webb] grove in Tulare, CA, using tTEM, a towed transient electromagnetic (tTEM) geophysical method. In order to interpret reliable information about sediment type from the tTEM data, a transform from the tTEM-derived property, electrical resistivity, to sediment type is required. The uncertainty associated with derived models of sediment type can be significantly reduced if a site- and dataset-specific transform is used. Cone penetrometer testing (CPT) was conducted at five locations, strategically selected based on a review of the tTEM data. Co-located measurements of sediment type, derived from the CPT, and electrical resistivity, derived from the tTEM data, were used to create a resistivity-to-sediment-type transform, with sediment type classified as either coarse-grain-dominated (sand and gravel) or fine-grain-dominated (silt and clay) material. The transform captured the uncertainty associated with variable water salinity and content, the resolution of the tTEM data, and other components of the tTEM measurement workflow. Using this transform, models of sediment type were generated for the unsaturated zone at the site. Within these models are features, which we interpret as potential recharge pathways, corresponding to high fractions of coarse-grain-dominated material amongst regions of fine-grain-dominated material. The workflow developed at this site can provide a framework for using tTEM and CPT for recharge site assessment.

中文翻译：

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通过整合地表地球物理学和锥形贯入仪测试进行补给场评估

在潜在的受管理含水层补给点，识别从地表到地下水位的导水沉积物的连接路径的能力有助于最大限度地降低与补给操作相关的成本和风险。先前已在杏仁中获得了空间密集的数据集 [ Prunus dulcis(Mill.) DA Webb] Grove in Tulare, CA，使用 tTEM，一种拖曳瞬态电磁 (tTEM) 地球物理方法。为了从 tTEM 数据中解释有关沉积物类型的可靠信息，需要从 tTEM 派生属性、电阻率到沉积物类型的转换。如果使用特定于站点和数据集的转换，可以显着降低与沉积物类型派生模型相关的不确定性。锥入度计测试 (CPT) 在五个位置进行，根据对 tTEM 数据的审查进行战略选择。来自 CPT 的沉积物类型和来自 tTEM 数据的电阻率的共同定位测量用于创建电阻率到沉积物类型的转换，沉积物类型分为粗粒为主（砂和砾石）或细粒为主（粉砂和粘土）材料。转换捕获了与可变水盐度和含量、tTEM 数据的分辨率以及 tTEM 测量工作流程的其他组件相关的不确定性。使用这种变换，可以为现场的非饱和带生成沉积物类型模型。这些模型中有一些特征，我们将其解释为潜在的补给途径，对应于细颗粒主导材料区域中粗颗粒主导材料的高比例。该站点开发的工作流程可以为使用 tTEM 和 CPT 进行充电站点评估提供框架。tTEM 数据的分辨率以及 tTEM 测量工作流程的其他组成部分。使用这种变换，可以为现场的非饱和带生成沉积物类型模型。这些模型中有一些特征，我们将其解释为潜在的补给途径，对应于细颗粒主导材料区域中粗颗粒主导材料的高比例。该站点开发的工作流程可以为使用 tTEM 和 CPT 进行充电站点评估提供框架。tTEM 数据的分辨率以及 tTEM 测量工作流程的其他组成部分。使用这种变换，可以为现场的非饱和带生成沉积物类型模型。这些模型中有一些特征，我们将其解释为潜在的补给途径，对应于细颗粒主导材料区域中粗颗粒主导材料的高比例。该站点开发的工作流程可为使用 tTEM 和 CPT 进行充电站点评估提供框架。对应于细晶粒主导材料区域中粗晶粒主导材料的高比例。该站点开发的工作流程可以为使用 tTEM 和 CPT 进行充电站点评估提供框架。对应于细晶粒主导材料区域中粗晶粒主导材料的高比例。该站点开发的工作流程可以为使用 tTEM 和 CPT 进行充电站点评估提供框架。