Periodic behavior of groundwater level fluctuations in residential areas

Abstract

For residential cities and their suburbs the continuous increase in groundwater level constitutes a common problem that can threaten the buried pipeline systems and structures, as well as road pavements. In this paper, the periodic pattern of groundwater level fluctuations is investigated for six monitoring wells located in residential areas in Kuwait. Monthly water level measurements obtained from the monitoring wells for periods varying from 8 to 10 years are employed to examine the relationship with monthly-averaged temperature and -totaled rainfall. The periodograms of the water level, rainfall, and temperature data are also determined. The results reveal that the annual periodicity typically observed in the last two climatological data sets can significantly be identified in all the series of subsurface water level examined here. Other periodicities of 27 and 18 months existing in the periodogram of rainfall are identified in two and four water level series, respectively. It is advocated here that the 27-month period present in the rainfall data of Kuwait is attributed to the well-known Quasi-Biennial Oscillation in zonal wind, which has been reported by many researchers for areas near the equator such as India and Indonesia. A time series model that triggers the influence of the detected periodicities is developed for the water level data to show an example of exploiting the fluctuation pattern for providing forecasts of groundwater table changes. The model can possibly be used to set a time plan for starting a continuous dewatering process to avoid problems related to groundwater level rise in residential areas.