The dynamic behavior of groundwater flow and salt transport is affected by tide and pumping in coastal multilayered aquifers. In this paper, two groups of experiments were conducted considering different constant head inland boundaries. The fluctuation of the groundwater level and the process of seawater intrusion in the multilayered aquifers were observed. A two-dimensional SEAWAT model is developed to simulate the seawater intrusion to coastal aquifers under the influences of tidal fluctuation and groundwater exploitation. The hydrogeological parameters in the model are calibrated by the records of the groundwater level and salinity measurements. The results showed that the simulated groundwater level and salt concentration match the observation well. The groundwater level has the characteristics of periodic fluctuation with tide. The lag time of the groundwater level fluctuation in each monitoring point increases slightly with the increasing distance from the saltwater chamber. For the low tide, the inland freshwater recharge has main effect on groundwater level fluctuation. The rising tide has a negative effect on the drawdown of the groundwater level induced by pumping. For the high tide, the tide plays a major role on groundwater level fluctuation, compared with the inland freshwater recharge. Compared with the condition of high head of inland recharge, larger saltwater intrusion lengths and area have been observed and simulated in the aquifer, which means that faster inland motion of the seawater wedge would occur when the inland recharge is small in the coastal aquifers. It revealed that inland recharge plays a major role in the seawater intrusion for the same pumping rate of groundwater in different seasons. The analysis provides insights into how the tide fluctuation, groundwater pumping, and inland recharge effect on the area and rates of seawater intrusion.

Large scale 3D seepage analysis of whole pumped storage power station project area Hongwei Zhang, Zhenzhong shen, Meng Tian et al. Abstract In this paper, the finite element software FEFLOW is used to simulate the seepage field of the interlayer staggered zone C2 in the basalt of Jinsha River Basin. The influence of the interlayer staggered zone C2 on the building is analyzed. Combined with the waterproof effect of current design scheme of anti-seepage curtain, the seepage field in the interlayer staggered zone C2 is discussed under different design schemes. The optimal design scheme of anti-seepage curtain is put forward. The results showed that the case four can effectively reduce the head and hydraulic gradient of underground powerhouse area, and improve the groundwater seepage field in the plant area. IntroductionIn the study of last 20 years, the shape of fault is not described as only a single shear zone. It may has multiple parallel shear zones simultaneously, with the fracture zone around it (Wibberley et al, 2008). The primary lens may be even formed in the shear zone (Faulkner et al, 2003). The permeability of the shear zone is larger than that of the surrounding rock fracture zone. Recently, there are many numerical simulation methods for the development of the interlayer staggered zones and their hydraulic characteristic (Brown and Bruhn, 1998;Jourde et al., 2002; Matthai and Belayneh, 2004;Lunn et al., 2008). In these methods, the faults are considered as a collection of multiple fractures of different size. For example, Odling et al. (2004) simulated the faults using the discrete element method, based on the development and distribution of the main water conducting fracture. It is particularly important to evaluate the permeability of the interlayer staggered zones of basalt, in order to analyze and evaluate the effect of groundwater movement on the engineering problem, such as the water gushing from the underground power house, seepage deformation of the interlayer staggered zones, and the slope stability, etc. The permeability of the interlayer staggered zone will affect the stability of the underground buildings. In this paper, the finite element software FEFLOW is used to simulate the seepage field of the interlayer staggered zone C 2 in the basalt of Jinsha River Basin. The influence of the interlayer staggered zone C 2 on the building is analyzed. Combined with the waterproof effect of current design scheme of anti-seepage curtain, the seepage field in the interlayer staggered zone C 2 is discussed under different design schemes. The optimal design scheme of anti-seepage curtain is put forward.