MONITORING AND MANAGEMENT OF WATER LOGGING PHONOMENA USING GEOELECTRICAL AND HYDROLOGICAL TECHNIQUES IN EL BUSTAN AREA, WESTERN PART OF THE DELTA

The desert lands lying to the west of the Nile Delta represent the natural extension areas of the Nile Delta where the old agricultural reclamation projects are started since 1950s. El-Bustan area represents one of these areas where the reclamation process started in the last decade of the 20th century. The continuous rising of the groundwater level caused the problem of water logging and deterioration of the reclaimed lands in the area. The integrated geoelectrical and hydrological studies through the present study will help in the solution of such problems through the monitor of the groundwater parameters (depth to water, water levels and salinity) with time. The quantitative interpretation of the geoelectrical measurements and the hydrological data of the drilled wells in 1992 and the present work led to the detection of three main geoelectrical units (A, B, and C). Unit "A" consists of dry clayey sand, sand and gravels sometimes intercalated with clay lenses. The thickness of this unit represents the depth to water which ranging between 9 - 28 m in 1992 and 2 – 23 m in 2011 . The decrease in the thickness of this unit in 2011 was reflecting an increase of the water level with time through vertical percolations of irrigated water or lateral seepage from the surface canals that causing the problem of water logging. Unit "B" represents the water-bearing formation in the study area, the upper part of this unit consists of clayey sand and sand deposits changing at the lower part to clayey sand, gravely sand and gravels having higher resistivity than that of the upper part. Unit "C" represents the last detected geoelectrical layer exhibiting relatively low resistivity values compared with that of the upper two units reflecting an increase in clay content. The interpretation of the 2-Dimension electrical resistivity tomography (ERT) profiles that carried out perpendicular to El-Bustan Canal revealed the presence of seepage from El-Bustan canal to the aquifer. The water level varies from 3 to 15m in 1992 and from 8 to 25m in 2011 with general increase with time which considered as one of the main reasons that causing the problem of the water logging. The water salinity varies from 662 to 1571ppm in 1992 and from 505 to 1507ppm in 2011 with general decrease with time reflecting the seepage of the fresh surface water of El-Bustan Canal to the aquifer. The integration of the geoelectrical and hydrological studies led to define precisely the causes of the water logging problem in the area. Through the periodical monitor and good management of the groundwater parameters as well as constructing good drainage systems will solve the effect of the water logging problems and
36 Al Temamy, A. M.M. and Ibrahim, S. M.M.
consequently decrease the deterioration of the reclaimed areas which finally will disappear and leading to increase the land productivity of such areas.