Water Quantity and Quality of Mansar Lake Located in the Himalayan Foothills, India

Abstract

Bathymetric survey and physico-chemical analysis of Mansar Lake, located in the Himalayan foothills in the state of Jammu and Kashmir, India, were carried out to assess water quantity and quality. The bathymetric survey indicated that Mansar Lake, with a surface area of 0.59 × 10⁶ m² at present outflow level, has a maximum depth, length and width of 38.25 m, 1204 m and 645 m, respectively. The lake mean width is 490 m, mean depth is 21 m, and mean slope of the lake floor is 0.14 m·m⁻¹. The storage capacity of the lake up to present outflow level is 11.57 × 10⁶ m³. Vertical variation of temperature, pH, electrical conductivity, dissolved oxygen, hardness and alkalinity suggest that Mansar Lake undergoes complete mixing during January and February and is stratified in other months. Calcium, magnesium and sodium are the dominant cations, and bicarbonate the dominant anion. Analysis of chemical parameters shows that the lake water is of Ca-Mg-HCO₃-CO₃ type. Phosphate concentration >0.03 mg·L⁻¹ in the Mansar Lake water indicated that the lake is eutrophic. Suitable measures have been suggested for sustainable management of Mansar Lake.

Key Words:

• bathymetry
• water quality
• temperature
• DO
• water level
• eutrophication
• Mansar Lake
• India