The Influence of Lithostratigraphy on the Type and Quality of Stored Water in Mujib Reservoir-Jordan
This study was carried out to investigate the impact of drainage basin?s lithostratigraphy
on the quality and type of stored water in the Mujib dam reservoir.
The water samples were collected on a monthly basis from surface water
from January 2012 to December 2015. The classifications of collecting water
samples for domestic and irrigation purposes were based on different physicochemical
parameters such as pH, EC, TDS, TSS, Na+, K+, Ca2+, Mg2+, Cl?,
24
SO ? , 3 HCO? , 4 NH+ , 3 NO? , 2 NO? , SAR, RSC, SSP, RSBC, PI, MAR, KR,
and TH. All analyzed water samples were satisfied the Jordanian permissible
limit and graded as ?fresh water?. The hydrochemical indices (Mg/Ca and
Cl/HCO3) and Cation Exchange values (CEV), indicating that the surface water
chemistry is due to the rock weathering minerals with respect to their inland
origin. The water samples have complied within the respective limits in respect
of pH, EC, SAR, RSC, RSBC, MAR, KR, SSP and PI, and hard in respect of TH
which may be due to the dissolution of the weathered rocks. Abundance of cations
and anions is in the following order: Ca > Na > Mg > K and HCO3 > SO4 >
Cl > NO3 during the period 2013-2015 and SO4 > HCO3 > Cl > NO3 through
2012. Thus, calcium and bicarbonate?sulfate are the dominant ions present in
the surface water of this study. Piper diagram suggested that carbonate and
gypsum weathering is the dominant process controlling reservoir water chemistry
in the basin area. The quality and type of surface water can be modified by
the lithology of the catchment area. The hydrogeochemical study of Mujib reservoir
water indicated that the water quality is safe for drinking and agricultural
purposes.