Hydrogeological and hydrochemical features of Wadi Adam, Makkah Al-Mukarramah Area

الملخص EN

The aim of this research is to assess the groundwater quantity and quality potentials of Wadi Adam as an additional strategic future water supply for Makkah Al-Mukarramah area.

Wadi Adam is one of the undeveloped Arabian Shield Wadis, located 50 km south of Makkah Al-Mukarramah city.

This Wadi drains a catchment area of about 380 km2 and receives a moderate amount of rainfall of about 160 mm year1.

Water table map was constructed for the existing unconfined alluvial aquifer.

The hydraulic gradient is about 0.008.

Average transmissivity of 142 m2 day1 were calculated and the average storativity value is about 0.1, which indicated that the aquifer in this area is of moderate potential.

The recharge rate to this basin, using chloride mass-balance method, is about 3 × 106 m3/year.

The amount of the natural discharge into the Red Sea is about 0.9 million m3/year.

The hydrochemical study indicated that the average total dissolved solids of the groundwater is 1500 mg/l.

This means that this groundwater is suitable for irrigation and non-drinking purposes.

Concentrations of trace elements are generally within the normal limits.