Reservoir water quality: a case from Jordan

Area of Science:

• Environmental Science
• Water Resource Management
• Limnology

Background:

• Jordan's reliance on reservoirs for water supply necessitates rigorous water quality monitoring.
• Mujib Dam is a key water source in central western Jordan, requiring detailed assessment.

Purpose of the Study:

• To evaluate the spatial distribution (vertical and horizontal) of water quality parameters in Mujib Dam reservoir.
• To identify factors influencing water chemistry and potential impacts on water quality.

Main Methods:

• Analysis of various water quality parameters including pH, dissolved oxygen (DO), total dissolved solids (TDS), major ions, nutrients (TN, TP), trace metals, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and chlorophyll a.
• Assessment of vertical and horizontal variations in these parameters.

Main Results:

• Near-neutral pH, slight decreases in DO and TDS with depth.
• Insignificant variations in major ions and nutrients vertically and horizontally, except for higher total nitrogen (TN) in the western part.
• Rock weathering and dissolution identified as primary sources of water chemistry.
• Trace metal levels were generally consistent vertically.
• Elevated COD, BOD5, and chlorophyll a in the northwestern corner indicate localized impacts.
• Phosphorus identified as the limiting nutrient for algal blooms, with overall oligo-mesotrophic conditions.

Conclusions:

• Mujib Dam's water quality is generally stable, with localized impacts from upstream agricultural activities.
• Rock weathering is the dominant factor controlling water chemistry.
• Phosphorus limitation and oligo-mesotrophic conditions suggest potential for managing algal blooms.