Numerical modelling of tide-induced beach water table fluctuations

Field studies have shown that the elevation of the beach groundwater table varies with the tide and such variations affect significantly beach erosion or accretion. In this paper, we present a BEM (Boundary Element Method) model for simulating the tidal fluctuation of the beach groundwater table. The model solves the two-dimensional flow equation subject to free and moving boundary conditions, including the seepage dynamics at the beach face. The simulated seepage faces were found to agree with the predictions of a simple model (Turner, 1993). The advantage of the present model is, however, that it can be used with little modification to simulate more complicated cases, e.g., surface recharge from rainfall and drainage in the aquifer may be included (the latter is related to beach dewatering technique). The model also simulated well the field data of Nielsen (1990). In particular, the model replicated three distinct features of local water table fluctuations: steep rising phase versus flat falling phase, amplitude attenuation and phase lagging.

The alcohol withdrawal syndrome

The alcohol withdrawal syndrome (AWS) is a set of signs and symptoms that typically develops in alcohol-dependent people within 6–24 h of their last drink. It may occur unintentionally if abstinence is enforced by illness or injury, or deliberately if the person voluntarily stops drinking because of an alcohol-related illness, or as a prelude to becoming and remaining abstinent. The signs and symptoms of the syndrome (panel) are largely, but not exclusively, those of autonomic hyperactivity, the reverse of the effects of alcohol intoxication. They represent a homoeostatic readjustment of the central nervous system (CNS) to the neuroadaptation that occurs with prolonged alcohol intoxication.1 RC Turner, PR Lichstein and JG Peden et al., Alcohol withdrawal syndromes: a review of pathophysiology, clinical presentation and treatment, J Gen Intern Med 4 (1989), pp. 432–444. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (39)1 They vary in severity from mild to severe.1