Development of River-Stage Tomography for Characterizing Groundwater Basins

叶天琦，大学。亚利桑那州开发用于表征地下水基础的河流状态层析成像通过一种可靠的盆地尺度含水层表征的实用方法，将大大提高模拟地下水盆地中通量和运移的可实现的可靠性。在一个绵延数百平方公里的盆地中进行抽水测试以产生应力是不现实的，河流过程线的下游通道会产生可用的含水层应力。大范围的影响范围、发生频率和激发的空间缓解使河流水位变化成为用于流域尺度水力层析测量的理想能源，用于绘制含水层非均质性图，在那里监测含水层响应。以前的工作证明了二维深度-平均耦合河流和地下水模型用于地下水流域特征描述的可行性，这个新项目现在正在扩大这一过去的工作，以开发一个用于描述含水层特征的三维模型。该方法正通过在台湾中西部密集仪器的潮水河冲积扇上的应用进行测试和验证。该方法从海量数据出发，按顺序确定不同位置水位变化引起的应力，并在多口井中记录含水层响应。然后采用随机参数估计程序，使用基于地质统计学的方法来估计代表非均质含水层的参数。该方法引入了层析成像范例，认识到时间和空间可变的降水驱动的水文过程的重复性质为估计含水层水文地质参数提供了非完全重叠的信息。这项工作的目标是通过更好地了解河流和地下水流域之间的相互作用，从而产生广泛的影响，以支持水资源管理和通过联合用水加强环境保护。实践者还将大大受益于拥有一种非侵入性技术来表征流域水文异质性和与表征有关的不确定性。它们还将获得一个宝贵的工具，用于评估气候变化对地下水资源的影响。将努力通过传播宣传和解释这一方法，以促进这些贡献的应用。

Jim Tian-Chyi Yeh, Univ. of ArizonaDevelopment of River-State Tomography for Characterizing Groundwater BasinsThe achievable reliability in modeling fluxes and transport in groundwater basins would be greatly enhanced by a practical method for reliable basin-scale aquifer characterization. Where it is not practical to conduct pumping tests to induce stresses throughout a basin stretched over hundreds of square kilometers, the downstream passage of river hydrographs create aquifer stresses that can be used. The large area of influence, frequency of occurrence, and spatial mitigation of the excitation make river stage variation an ideal energy source for use in basin-scale hydraulic tomographic surveys to map aquifer heterogeneity where aquifer responses are monitored. Previous work has demonstrated the viability of a 2D depth-average coupled river and groundwater model for groundwater basin characterization and this new project is now engaged in expanding on this past work to develop a 3D model for aquifer characterization. The approach is being tested and validated through application to the intensely instrumented Cho-Shui River alluvial fan in central western Taiwan. The method starts from an immense amount of data to determine the stress induced by river-stage variation at various locations sequentially and aquifer responses recorded in numerous wells. It then employs a stochastic parameter estimating procedure using geo-statistically-based methodology to estimate parameters for representing a heterogeneous aquifer. The approach imports the tomography paradigm by recognizing that the recurrent nature of temporally and spatially variable precipitation-driven hydrologic processes provides non-fully overlapping information for estimating aquifer hydrogeologic parameters. The work is targeted to have broad impacts through greater understanding of the interactions between rivers and groundwater basins that would support water resources management and greater environmental protection through conjunctive water use. Practitioners will also greatly benefit by having a non-invasive technology for characterizing basin hydrologic heterogeneity and the uncertainty associated with the characterization. They will also gain a valuable tool for use in evaluating the effects of climate change on groundwater resources. An effort will be made to publicize and explain the methodology through communications that would facilitate applying these contributions.