Water and Solute Fluxes and their Structural Controls at Margins of Floodplain Aquifers

洪泛区含水层边缘的水和溶质通量及其结构控制

• 批准号: 518484432
• 负责人: Professor Dr.-Ing. Olaf A. Cirpka
• 金额: --
• 依托单位: Arbeitsgruppe Umwelt- und Ingenieurgeophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/518484432?language=en
• 关键词: Water; Solute; Fluxes; their; Structural

In typical midland catchments in moderate climate, groundwater flow in floodplains is mainly down-valley oriented. However, the hydrological functioning of floodplain aquifers also depends on the presence or absence of major hydrogeological features, and the local groundwater systems are strongly influenced by water and solute fluxes across their margins. The goal of this project is to elucidate the hydrogeological drivers that determine these fluxes and assess the relative importance of the margins for the overall water balance and solute turnover in floodplain aquifers. The research will be conducted in the Ammer floodplain close to Tübingen (Southwest Germany), which is a typical representative for a mid-section floodplain in moderate climate and has already been studied by the applicants within CRC1253 CAMPOS. To reliably model and predict the hydrological functioning of a floodplain aquifer including its margins, it is essential to know the spatial position, geometry, and hydrogeological properties of water-transmitting structural features at these margins. We will therefore characterize the structural controls at the floodplain margins determining the flux of water and solutes through the floodplain aquifers. In this regard, we aim at labor- and cost-efficient methods to map the spatial extent and geometry of structural features at floodplain margins (using geophysical surveying) and characterize their hydraulic connectivity to the floodplain aquifers (using hydraulic tests). With special focus on the identified structural controls at the floodplain margins, we investigate the water fluxes and corresponding loads of solutes crossing the floodplain margins to quantify their relative contributions within the floodplain aquifer. We will especially investigate the temporal dynamics of the hydrological boundary conditions to identify under which conditions significant water exchange occurs. The experimental findings will inform a consistent numerical model of the floodplain aquifer for predicting signals of hydrogeological measurements and interpreting the results of the estimated dynamic exchange fluxes. Finally, we will compile the geological information gathered in the different investigation steps and in our previous work to perform a comprehensive geological interpretation to identify the guiding geological processes that determine the presence and effectiveness of permeable features at floodplain margins controlling exchange fluxes. This step will facilitate generalizing our findings and transferring it to other sites.

在气候温和的典型米德兰流域，洪泛区的地下水流主要是沿山谷向下的。然而，洪泛区含水层的水文功能也取决于主要水文地质特征的存在或不存在，当地地下水系统受到其边缘的水和溶质通量的强烈影响。本项目的目标是阐明水文地质驱动因素，确定这些通量和评估的相对重要性的利润率的整体水平衡和溶质周转在洪泛区含水层。本研究将在蒂宾根（德国西南部）附近的Ammer洪泛区进行，该洪泛区是中等气候下中段洪泛区的典型代表，申请人已在CRC1253 CAMPOS内进行了研究。为了可靠地模拟和预测洪泛区含水层（包括其边缘）的水文功能，必须了解这些边缘的输水结构特征的空间位置、几何形状和水文地质特性。因此，我们将描述河漫滩边缘的结构控制，确定通过河漫滩含水层的水和溶质通量。在这方面，我们的目标是劳动力和成本效益的方法来映射的空间范围和几何结构的特点在洪泛区边缘（使用地球物理测量）和表征其水力连通性的洪泛区含水层（使用水力测试）。特别注重在河漫滩边缘确定的结构控制，我们调查的水通量和相应的负载的溶质穿过河漫滩边缘，以量化其相对贡献内的河漫滩含水层。我们将特别研究水文边界条件的时间动态，以确定在哪些条件下发生显着的水交换。实验结果将通知一致的数值模型的洪泛区含水层预测信号的水文地质测量和解释的结果估计的动态交换通量。最后，我们将汇编在不同的调查步骤中收集的地质信息，并在我们以前的工作中进行全面的地质解释，以确定指导地质过程，确定控制交换通量的河漫滩边缘渗透特征的存在和有效性。这一步骤将有助于概括我们的调查结果，并将其转移到其他网站。