Variation of Soil Properties of Unsaturated Zone with Depth and Time at an Agricultural Site in Kuwait

To assess the feasibility of recovering water from the unsaturated zone, the soil data from this zone at three sites in an agricultural research station in Kuwait and the meteorological data from the station at the nearby location were analysed to investigate the variation of soil properties with depth and any relationship that might exist between these and some of the meteorological parameters. Automatic sensors were set at several depths within the three boreholes installed at the sites, to record the soil water content, temperature, and electrical conductivity (EC) at one-hour intervals. The results of the grain size analysis of the drill cuttings from different depths of these boreholes were used to determine the lithology of the sediment sequence penetrated. The extracts from the drill cuttings were chemically analysed. Graphical and statistical methods were used for the analysis of these data. It was concluded that down to the depth investigated (25 m), the depth and meteorology did not have much influence on the quantity and quality of the soil water content. A continuous increase in the soil water content with time was, however, observed over the monitoring period that was surmised to be related to the infiltration of winter rain and the irrigation water that might lead to water mounding. It was further concluded that there would be sufficient quantity and quality of soil water in the unsaturated zone of the study area that could be profitably recovered.