Lakhasly

4.Results and Discussion

Hydrogeologically, the various litho-units of the shallow aquifer in the study area can be grouped by coarse sand, sandy clay, silt and fractured limestone underlined by impervious clay (P1, P2, P3, P6, P9, P10 and P11) or li- mestone (P4, P5, P7 and P8) which prevent downward of irrigation water (Figure 7).The deteriorating mechanism of salt solution depends on two sources of water: humidity from condensation and groundwater from capillary rise In order to protect the antiquities from further accelerated deterioration, lowering of groundwater to safe levels was needed.Eventually, the salts will accelerate the flaking erosion and the fall of clay plaster and cement that has long afflicted the Ha- warah and Al-Lahun pyramids as well as the salt crystallization in the entrance (Figure 11).As well as, the subsoil water moves from the high level land located in the middle of the concerned area towards the low land (old cultivated land) located in the periphery of the new reclaimed land and the two ancient pyramids (Hawarah and Al-Lahun) causing serious waterlogging and dam- age of the old cultivated land.The observations on groundwater fluctuation (Figure 8) from January (2008) to January (2010) demonstrate arelatively increase in water table by about 0.02 m (the lowest at P3) to 0.08 m (the highest at P11).

4. Results and Discussion

Hydrogeologically, the various litho-units of the shallow aquifer in the study area can be grouped by coarse sand, sandy clay, silt and fractured limestone underlined by impervious clay (P1, P2, P3, P6, P9, P10 and P11) or li- mestone (P4, P5, P7 and P8) which prevent downward of irrigation water (Figure 7). The observations on groundwater fluctuation (Figure 8) from January (2008) to January (2010) demonstrate arelatively increase in water table by about 0.02 m (the lowest at P3) to 0.08 m (the highest at P11). The increase of groundwater levels occurred in practically all piezometers with different magnitudes with an annual average of 0.05 m. On the other hand, the water tables of the command area for the year 2008-2010 are delineated and the integrated maps are shown in Figure 9 and Figure 10. Comparing water levels of 1/2008 (Figure 9) and water level of 1/2010 (Figure 10), cleared that all the observation wells and the lakes have increase in the water level from 0.09 m (L2) to 0.02 m (p3). As well as, the subsoil water moves from the high level land located in the middle of the concerned area towards the low land (old cultivated land) located in the periphery of the new reclaimed land and the two ancient pyramids (Hawarah and Al-Lahun) causing serious waterlogging and dam- age of the old cultivated land. Groundwater threatens more than the great monument's stability. If water wicks up into the statue, it will leach salts from the limestone and deposit them on the surface of the stones. Eventually, the salts will accelerate the flaking erosion and the fall of clay plaster and cement that has long afflicted the Ha- warah and Al-Lahun pyramids as well as the salt crystallization in the entrance (Figure 11). The deteriorating mechanism of salt solution depends on two sources of water: humidity from condensation and groundwater from capillary rise In order to protect the antiquities from further accelerated deterioration, lowering of groundwater to safe levels was needed.

The hydrogeochemical characteristics of the sub-soil water in the study area are discussed through the chemi- cal analysis of eleven sub-soil water samples (beside irrigation canals water samples) collected during January 2008 (Table 2). The chemical analyses deal with the determination of major cations (Na, K, Ca" and Mg²) and anions (CO), HCO3, SO and CI). According to Chebotarev classification for salinity [22], the sub- soil water of the study area can be classified from brackish water to high saline water. The salt content of the water samples ranges from 32,816 mg/l (P8) to 4224.4 mg/l (P11). Furthermore, the salinity increases generally towards the northwest of the study area (Figure 12). Hyper-saline water is restricted to high land area reflecting the effect of gypsiferous shale beside the infiltration of high saline excess irrigation water. Saline water is re- stricted to low land in the periphery of the old cultivated land (P1, P2 and P11) reflecting the effect of fresh