| Author | Rana, Krishna |
| Call Number | AIT Thesis no.EV-90-9 |
| Subject(s) | Water quality management--Nepal|--Phewa Lak
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | This study was undertaken to assess the Phewa Lake water
quality so as to provide baseline data for future use and to
suggest remedial measures for pollution control. The study period
was relatively short and bimonthly samples from September to
December were analysed in Kathmandu ( 200 km. from the site ) .
From this study it can be said that nutrient concentrations
(Pav = 0 . 122 mg/l & Nav > 0 . 71 mg/l ) remained very high resulting
in a high primary productivity; and the Lake falls in the
e u trophic category. Thermal stratification and anoxic condition
of sediments remained till October; in Dec ember the water
temperatures started falling and complete mixing occurred till
the temperatures remained constant at 17.5 °C and the dissolved
oxygen remained at 7 mg/l throughout the depth.
BOD a nd COD concentrations increased (upto 9 & 184 mg/l
respectively) towards the downstream of Baraha Temple suggesting
inflow of organic matter from shore developments and/or blooming
of dead algae , whereas the coliform concentrations decreased
towards the Lake center and downstream (3000 MPN/100 ml) compared
to t h e inflow (17000 MPN/100 ml ) of the Lake.
It seemed that t he Lake sediments, rich in nutrients , released the accumulated P and N to the overlaying waters .
Nutrients and silt might come mainly from non-point sources
(agricultural and deforested l ands ).
Tentative magnitude of pollution loads (P = 14 t/a) was
estimated using WHO waste factors and the Lake retains 38 % of
the total P (1 30 kg/d) and 78 96 of the ortho-P (28 kg/d) |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Verink, Johan
|
| Examination Committee(s) | Paudyal, Guna N. ;Bhattarai, Kiran K. ; Mino, Takashi
|
| Scholarship Donor(s) | FINNIDA |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |