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Phytoplankton
Diversity in Sharavati River Basin, Central Western Ghats
-- Desai S R, Subash Chandran M D and Ramachandra T V
Phytoplankton
is one of the most rapid detectors of environmental changes.
Pollution stress reduces the number of algal species but increases
the number of individuals. Phytoplankton composition was assessed
in 16 localities of the Sharavati River basin. A total of
216 species belonging to 59 genera (belonging to Bacillariophyceae,
Desmidials, Chlorococcales, yanophyceae, Dinophyceae, Euglenophyceae
and Chrysophyceae) were recorded. During the sampling, 100,
117 and 110 species of phytoplanktons were recorded in collection-I,
II and III respectively. Species composition was almost uniform
in all the three collections. Species compositions as well
as population of diatoms were more in streams, while that
of desmids was more in reservoir water. Species diversity
and species richness were not uniform in any of the stations
and in any of the three collections. Various pollution indices
showed the oligotrophic nature of the reservoir waters with
slight organic pollution in stream waters.
©
2008 The Icfai University Press. All Rights Reserved.
Effect
of Contaminants on the Permeability of
Sand-Kaolinite Mixture -- R
K Dutta
The
paper presents the effect of contaminants on the permeability
of sand-kaolinite mixtures. Two types of contaminants such
as kerosene and diesel have been investigated. The results
obtained show that the permeability of sand-kaolinite mixture
decreases with increase in the content of kerosene and diesel.
They further reveal that kerosene was more effective in reduction
of permeability of the sand-kaolinite mixture than diesel.
Hence sand-kaolinite mixture contaminated with kerosene or
diesel can effectively be used as perfect material for sealing
barriers against oil contaminant leakage. Further, multiple
regression analysis was performed on the test results of permeability
to develop regression models. The prediction made by the regression
models was compared with the experimental results. The results
of multiple regression analysis reveal that the regression
models reproduced results obtained from the permeability tests
quite well and the models can be used for determining the
values of permeability of sand-kaolinite mixture contaminated
with kerosene and diesel.
©
2008 The Icfai University Press. All Rights Reserved.
Development
and Application of Unit Sediment Graph (USG) for Sediment
Yield Modeling -- Chandramohan T, Samson
Mathew and Balchand A N
The
use of instantaneous sediment measurements is not adequate
for the modeling of sediment and pollutant transport resulting
from a rainfall event. A sediment graph associated with a
runoff hydrograph provides temporal variation of sediment
flow, which can be used for studying suspended sediment dynamics.
In this study, Unit Sediment Graphs (USGs) were developed
for three watersheds with varying characteristics. These USGs
were used further to estimate sediment yield resulting from
rainfall events and compared with the observed sediment rates
from the watersheds. It is found that the Unit Sediment Graph
model is capable of simulating the total sediment load, peak
transport rate and temporal distribution.
©
2008 The Icfai University Press. All Rights Reserved.
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August'08