In this study, the spatial distribution of measured soil moisture was analyzed on the platform of multivariate modeling. Soil moisture time series for two seasons were selected and used for analysis to reveal similarities and differences in soil moisture responses for a few rainfall events. The development of a soil moisture transport process that considers the representative element volume and uncertainty of soil media provides the hydrological basis for time series modeling. The systematic procedure of Box–Jenkins with noise modeling was used to delineate the final models for all monitoring points. The physical basis of mass balance and the continuity in inflow contribution, as well as statistical criteria, were used in the model selection procedure. Heuristic approaches provide the spatial distribution of selected models along the transect of a hillside. Comparative analysis for two different depths and seasons provide an understanding of the variation in soil moisture transfer processes at the hillslope scale. Differences in soil moisture models for both depths and seasons are associated with eco-hydrological processes. The relationships between distributed topographic features and modeling results were explored to configure dominant hydrological processes for each season. 相似文献
We present a framework for the coupling of fluid-filled fracture propagation and a genetic inverse algorithm for optimizing hydraulic fracturing scenarios in porous media. Fracture propagations are described by employing a phase field approach, which treats fracture surfaces as diffusive zones rather than of interfaces. Performance of the coupled approach is provided with applications to numerical experiments related to maximizing production or reservoir history matching for emphasizing the capability of the framework. 相似文献
A phase-field approach for fluid-driven fracture propagation in porous media with varying constant compatible stress boundary conditions is discussed and implemented. Since crack opening displacement, fracture path, and stress values near the fracture are highly dependent on the given boundary conditions, it is crucial to take into account the impact of in situ stresses on fracturing propagation for realistic applications. We illustrate several numerical examples that include the effects of different boundary conditions on the fracture propagation. In addition, an example using realistic boundary conditions from a reservoir simulator is included to show the capabilities of our computational framework. 相似文献
Partitioning tracer tests, as an alternative to the core sampling method, were conducted to quantify the degree of saturation
of water and nonaqueous phase liquids (NAPL) in the vadose zone. Hydrocarbon gases, which have less effect on global warming
than conventional tracers, were used as partitioning tracers. Column tests using CH4, C3H5, and C4H10 as non-partitioning and partitioning tracers were performed to determine the retardation factor and partition coefficient
of the tracer into water and NAPL. The retardation factors of these tracers were estimated to be in the range of 1.0–7.0 based
on breakthrough curves of the tracers. The partition coefficient of C3H5 to water and diesel phase was calculated to be 0.57 and 8.45, respectively. For a heavier tracer, C4H10, the partition coefficient to the water and diesel phases was 1.2 and 40.5, respectively. The average value of water and
diesel saturation estimated from column tests agreed well with known values in unsaturated soil. A residence time longer than
7.5 h within soil pores was found to provide local equilibrium partitioning of the tracer to the diesel phase. The concentration
of tracer had no effect on the partitioning process. 相似文献
The salinity of groundwater in an estuarine delta plain is sometimes related to the presence of an estuarine dam. To understand groundwater processes and salinity variation, time series data on the river water level, groundwater level, and groundwater electrical conductivity were collected for the Nakdong River in southeastern Republic of Korea. Sampling was undertaken upstream of the estuarine barrage system, which is opened and closed depending on upstream flow and seawater level. Comprehensive correlation analysis was performed between the groundwater and river water levels using bubble plots between groundwater electrical conductivity and the hydrological variables. Comparative analysis between the correlations and the field measurements of the hydrological variables indicated a negligible flux connection between the river and groundwater. Oscillatory pressure wave propagation from the river boundary explains the response patterns of the groundwater level. There were different response times for the rising and falling of the river water. Electrical conductivity in groundwater is not directly associated with that of the river except in one well close to the river boundary. The response patterns of groundwater electrical conductivity were explained by potential anthropogenic activity. Further transfer modeling results also indicate a spatial explanatory response pattern for the groundwater level. No spatial patterns in the models of electrical conductivity indicate that the hydrological processes are different with respect to the groundwater level and electrical conductivity.