Southwest Florida Water Management District, Brooksville, FL 34604, USA.
Ground Water. 2010 Jul-Aug;48(4):549-59. doi: 10.1111/j.1745-6584.2009.00673.x. Epub 2010 Jan 22.
The recent development of the Conduit Flow Process (CFP) by the U.S. Geological Survey (USGS) provides hydrogeologic modelers with a new tool that incorporates the non-Darcian, multiporosity components of flow characteristic of karst aquifers. CFP introduces new parameters extending beyond those of traditional Darcian groundwater flow codes. We characterize a karst aquifer to collect data useful for evaluating this new tool at a test site in west-central Florida, where the spatial distribution and cross-sectional area of the conduit network are available. Specifically, we characterize: (1) the potential for Darcian/non-Darcian flow using estimates of specific discharge vs. observed hydraulic gradients, and (2) the temporal variation for the direction and magnitude of fluid exchange between the matrix and conduit network during extreme hydrologic events. We evaluate the performance of CFP Mode 1 using a site-scale dual-porosity model and compare its performance with a comparable laminar equivalent continuum model (ECM) using MODFLOW-2005. Based on our preliminary analyses, hydraulic conductivity coupled with conduit wall conductance improved the match between observed and simulated discharges by 12% to 40% over turbulent flow alone (less than 1%).
美国地质调查局（USGS）最近开发的管道流过程（CFP）为水文地质模型提供了一种新工具，该工具结合了具有喀斯特含水层特征的非达西、多孔隙流特性。CFP 引入了新的参数，这些参数超出了传统的达西地下水流动代码的参数。我们对喀斯特含水层进行了特征描述，以收集在佛罗里达州中西部一个测试点评估该新工具的数据，该测试点具有管道网络的空间分布和横截面面积的信息。具体来说，我们对以下内容进行了特征描述：（1）使用比观测水力梯度的比流量估计值，对达西/非达西流动的可能性进行了描述；（2）在极端水文事件期间，基质和管道网络之间的流体交换的方向和幅度的时间变化。我们使用站点尺度的双重孔隙模型评估 CFP 模式 1 的性能，并使用 MODFLOW-2005 将其性能与可比的层流等效连续体模型（ECM）进行比较。根据我们的初步分析，水力传导率与管道壁传导率相结合，将观测流量与模拟流量的吻合度提高了 12%至 40%，而单独的紊流（小于 1%）则提高了 12%至 40%。
