Abstracts of International Workshop on Environmental Biogeochemistry
Simulation of the Indian summer monsoon in the land-ocean atmosphere system of a coupled GCM
Lydia Dumenil
Max-Planck-Institute fuer Meterorologie
Bundesstr. 55, d- 201 46 Hamburg
Germany
A 150 year-long numerical simulation of present-day climate
using the Max-Planck Institute s coupled ocean-atmosphere model ECHAM4
-T42-OPYSC3 is analysed with regard to the interannual variability of the
strength of the Indian summer monsoon and its relation to land-surface and
ocean interactions. Individual years are categorised into three classes of
monsoons: normal, strong and weak (greater or less than one standard deviation
of precipitation over India). Theens embles of anomalous monsoons are then
sub-deviation of precipitation over India). Theens embles of anomalous monsoons
are then sub-divided into a composite of cases coinciding with sea surface
temperature (SST) anomalies in the Pacific related to the El Ni= F1o-Southern
Oscillation (ENSO) phenomenon and a second composite of anomalous monsoons
occurring when no SST anomalies are found in the Pacific. The coupled model
shows variations of the SST in the Pacific which are as large as and occur at a
similar frequency as in observations. Thus it provides the basis for arealistic
simulation of the interannual monsoon variability in ENSO- related conditions.
Flux and Fare of Fluvial Sediment Discharge to the Ocean, with Particular Emphasis on Southern Asia and Ocenia
John D. Milliman
School of Marine Science
College of Williman and Mary
Glucester Point, VA 231 85 USA
Analysis of sediment data from morel than 500 global rivers
shows two quite different trends, depending on whether one considers solid or
dissolved sediment. The geomorphic/tectonic character of the drainage basin and
the basin area have first-order controls on the solid sediment (SS) discharge
of most rivers. Toporgraphic control also served as a surrogate for tectonic
character of the basin, which in turn such things as eearthquakes, landslides
and - to some extent- the geological character of the rocks themselves. Younger
rocks are generally more easily eroded than older rocks; and sedimentary rocks
more erodable than metamorphic rocks. Climate (particularly precipitation) and
human impact also play important roles, often explaining deviations from the
load predicted on the basis of topography and basin are alone. Many of the
present-day smaller mountainous rivers discharge onto active margins with
narrow shelves. As such, there is often little chance for sediment storage on
land and relatively little chance for sediment to accumulate on the shelf. Most
of the sediment presumably escapes to the slope and the deep sea beyond. As
such, smaller mountainous rivers can serve as modern analogs of conditions as
they existed during lower stands of sea level. There also is some evidence
(although still controversial), for example, that rivers discharging eastwards
from New Guinea may be responsible for the anomalously high particulate
aluminium and iron contents found in the Equatorial Counter Current, which in
turn may fertilize the high productivity in the eastern equatorial Pacific. If
true, this would suggest that fluvial imprints on the global ocean may be far
greater and wider ranging than commonly believed.
Management of Environmental Information on Biogeochemistry - an overview
S.Annadurai and C. Chatterjee
School of Environmental Sciences
Jawaharlal Nehru University
New Delhi - 100 067, India
Information is a resource, which together with physical,
economical, technical and human resource is a must for national development.
Sustainable development, which has evolved as the goal for human welfare in
recent times, is rooted in the availability of right information to the right
person at the right place and at the right time. The need for information
arises at all levels, from that of senior decision-makers, at the national and
international levels to the grass roots and individual levels. Environmentally
sound decisions, which are a must for achieving sustainable development, are
not possible in an information vacuum.
Environmental information is, therefore, of vital
importance. Realising the importance of environmental information, an
Environmental Information System (ENVIS) has been established by the Ministry
of Environment and Forests in 1982 to provide information to decision-makers,
policy- planners, scientists, etc. all over the country. Dissemination of
information to the users is the most vital component in the whole system for
providing the users satisfaction. ENVIS is a decentralised network information
system consisting of Focal Point in the Ministry coordinating the activities of
a chain of 24 subject specific centres, known as ENVIS Centres located in
various prestigious institutions/organisations all over the country. The
purpose of the ENVIS Centre is to cater to the needs of the people do not have
access to highly equipped libraries and network systems. ENVIS Centre is
building up a good collection of books, reports and journals in the particular
subject area of environment. Establishment of linkages with all information
sources in the particular subject of environment. Repsonding to users queries.
Establishment of a data Bank on some selected parameters relating to the
subject area. Identification of gaps in the subject area and action to fill
these gaps.Bringing out newsletter/publications in the subject area for wide
dissemination.
Methane: Cycling and Climatic variability
Purvaja Ramachandran and R. Ramesh
Institute for Ocean Management
Anna University
Madras -600 025
There are several potential climate feedback that could
affect the atmospheric and the budget. Traditionally, temperature increases are
assumed to generate increases in CH4 emissions. Recent calculations suggest a
moderate increase in CH4 emissions in a 2 X CO2 scenario (Harriss et al.,
1993). Methane is the only long- lived gas that has clearly identified chemical
feedback: increases in atmosphertic CH4 reduce the concentration of
tropospheric OH articles, increase the CH4 lifetime and and hence amplify the
original CH4 perturbation. The chemical feedbacks of CH4 on OH chemistry
results in the reduction of CH4 removal rate ranging from - 0.17% to -0.35% for
each 1% increase in CH4 concentration. Also predicted increases in tropospheric
O3 varied by a factor of three or more averaging about 1.5 ppbv throughout most
of the troposphere in both tropics and summertime mid latitudes. Based on our
existing knowledge on the importance of CH4 to the tropospheric chemistry, and
its chemical feedback, extensive studies on quantifying and refining the source
data base was our primary objective. This paper discusses the importance of CH4
as a greenhouse gas, its cycling in rice paddy and in wetlands and its
implication to the threat of global warming.
The effect of organic matter on chemical weathering in tropical area
Dupre B. (1), Viers J. (1), Oliva P.(1), Fortune
J.P.(1), Braun J. J.(2), Martin F.(1) and Robain, H.(2)
(1) Laboratoire de Geochimie,
OMP-UMR-CNRS 5563, 38 rue des 36 ponts, 31400 Toulouse
(2) ORSTOM TOA, BP 1857, Yaounde,
Cameroun
We have recently works on the chemical composition of the rivers
flowing in tropical region. We have shown that these rivers shown very peculiar
characteristics. High amount of COD, Al and Fe, low concentration of major
elements. We have interpreted these characeteristics by the effect of organic
matter on chemical weathering we have made chemical studies on a representative
small watershed. We describe below the main results we have obtained on this
watershed (Nsimi/Zoetele, South Cameroon). The Nsimi basin is a pilot site of
the PEGI program (programme d Environment de la Geosphere Intertropicale,
ORSTOM-CNRS) and it offers a unique opportunity to study weathering mechanisms
in a lateritic system within a small basin by coupling soil and water
chemistry. The lateritic cover in this site can reach upto 40 m in depth and
show two pedological distinct zones: 1) slope soils on the hills or elevated
areas nad2) hydromorphic soils in the swamp zone which represent 20% of the
basin surface. The first results obtained from this program show strong
chemical differences between waters located in slope zones (depleted inn
organic matter) and those pounded in swamp zones (enriched in organic matter).
The study was performed on waters samples taken from piezometric wells and
springs in slope areas, and from peezometric wells and marsh waters in the
swamp zones, between 1994- 1997. Soil samples analysed in this study were
collected during a well drilling in December 1996. Water samples were analysed
by high pressure liquid chromatography (HPLC; major actions and anions) and inductively-coupled
plasma mass spectrometry (ICP-MS; trace elements). Dissolved organic carbon was
measured by low temperature chemical oxidation (LTCO). Soil mineralogy was
characterised by x-ray diffraction (XRD), infrared spectroscopy (IR), scanning
electron microscopy (SEM), electron microprobe analysis (EMPA), and ICP-MS. The
results on water samples suggests the existence of chemical and special
heterogeneities of waters in the basin: coloured waters flooding the swamp zone
have much higher concentrations of both organic (e.g., DOC) and inorganic ions
(e.g., Ca, Mg, Na, K, Al, Fe, Th, Zr) than those from springs and groundwaters
form the hills (fig. 1). Nevertheless, these organic rich waters present
actions concentrations (i.e., Na, Ca, Mg, K) which are among the lowest
compared to that of most world rivers.
Microbiological Applications and Techniques in Biogeochemistry
K. A. Natarajan
Department of Metallurgy
Indian Institute of Science
Bangalore -560 012, India
Atleast four major mechanisms have been known for biological
removal of metalions from liquid effluents, namely, bioadsorption,
bioaccumulation, precipitation and volatilisation. In biodegradation, the
micro-organisms transform the organic chemicals into innocuous forms, degrade
them to carbon dioxide and water, besides decomposing them anaerobically.
Biosorption is primarily an adsorption-type phenomenon taking place through
electrostatic attraction of metal actions to the negatively charged cell
surfaces. Moreover, the chemical composition of the bacterial cell wall also
plays a role in biasorption through metal binding to exopolysaccharides,
proteins and other functional groups. Anionic and cationic sites are thus
available on bacterial cell walls. For example, Gram-positive Bacillus subtilis
wall has peptidogycan with COO- groups. In Bacillus licheniformis, the bulk of
the metal binding capacity is determined by teichoic and teichuronic acids.
Similar mechanisms are operative in Gram-negative bacteria also, where
lipopolysaccharides play a dominant role. Bioaccumulation is the process of
metal uptake by living microorganisms, dependent on metabolic energy. This
requires specific transport systems and depends on metal tolerance of the
organisms. Inter- as well as intra-cellular accumulation can occur. In both
biosorption and bioaccumulation, metal removal is a direct consequence of the
physical content between the metal ions and microorganisms. Metals can also be
removed from solution without the need for direct contact, the metal removal
being brought about by metabolites generated by the micro-organisms. For
example, heavy metals from solution can be removed by the activity of anerobic
heterotrophs such as sulphate reducers.
Status of Surface Water Quality in Sri Lanka
E.I.L. Silva
Institute of Fundamental Studies
Hantana Road, Kandy
SRI LANKA
The composition of surface water in the wet zone of Sri
Lanka is determined by the NaCl dominated rainwater whereas the rock dominance
plays an important role with respect to the composition of dry zone surface
water. The rock dominance also plays an important role in the wet zone where
Dolomite beds are drained. Faecal contamination is a common feature in the
surface water, while loading of phosphorus and nitrogen species from
agriculture lands, live stock and human settlements with poor sewerage
treatment facilities have promoted hypeutrophication. Pollution by trace
elements is confined only to the surface waters intercepting major cities and
urban centres. With respect to organic residues, the impact may be cronic.
Nevertheless, in terms of water quality, Sri Lanka s wet zone rivers draining
the lowland, midland and highland are suitable for domestic water supply after
appropriate treatment. Reservoirs, irrigation tends, and rivers draining the
lowland dry zone are suitable for wildlife propagation, agriculture, industrial
purposes and aesthetic enjoyment. Urban canals such as Mid-Canal in Kandy and
Nau Oya in Nuwara Eliya have been subjected to severe organic and inorganic
pollution. Care should be taken when hypeutrophic water is being used for
drinking even after chlorination. It is extremely important to determine the
concentrations of organic residues of commonly used pesticides even in the
water treated for drinking.
Physical Setting and Natural Resource Potential of the Western Ghats, India
K. Soman
Centre for Earth Science Studies
Akkulam, Thiruvananthapuram
Kerala - 695031, INDIA
The Western Ghats hill range, extending from Tapi estuary to
Cape-Comorin is one of the major physiographic divisions of India. It is the
watershed of Peninsular India. It contains some of the vestiges of Tropical
Evergreen Forests left in the country and is endowed with rich mineral
deposits, besides being the provenance of sediments in the western passive
continental margin of India. The hill range displays contrasting diversity in
physiographic setting and lithological and biological characteristics, which
may reflect in the nature and extent of sediment load and nutrient influx into
the western continental margin.
Distribution of Carbon and Phosphorus in river-backwater system of Kerala, India
Sujit Kumar Bajpayee and Anuradha Verma
School of Environmental Sciences,
Jawaharlal Nehru University,
New Delhi- 110067, India
River-backwater system is very dynamic system. Transfer of
mass occurs from one to another. C and P distribution between the two has been
studied in this paper. There is not much variation in bicarbonate concentration
in rivers between monsoon (6.4-13.4 mg/L) and post monsoon (8.2-15.7 mg/L).
Spatial variation also is not significant among the rivers south of Palghat
Gap. But there is marked increase in HCO3- concentration as one crosses the
Palghat Gap. Variation of HCO3- in backwater lakes is dependent on the level of
sea water intrusion and varies from 3.3 to 90.3 mg/L. PO4 concentration is low
ranging from 0.01 to 0.17 mg/L. There is higher PO4 concentration in backwaters
as compared to rivers. Most of sediment carbon in rivers and backwaters is
organic in nature. Sediment bound P is also high indicating anthropogenic
influences. CH4 emissions from backwaters ranges from 10.97 to 210.59 mg/m2/hr.
This variation is in accordance with the salinity gradient.
Dissolved and sediment bound organic matter in the west flowing rivers of Kerala
Dirk Wittkuhn
Institute of Biogeochemistry and Marine Chemistry
University of Hamburg
203 57 Hamburg, Germany
The amounts of TSS in our samples are very low. The
pre-monsoon batch has only two samples (one from the estuarine region of
Keedhri not belonging to the first group (< 15 mg/l). The mean TSS of the
pre-monsoon samples without the two deviations is 5.38 mg/l. Within the monsoon
samples this relationship is different. 50% of the samples belong to the second
class (15 - 50 mg/l). Six of the eighteen samples of this batch fall into the
first class (0 - 15 mg/l) and three belong to the third class (50 - 150 mg/l).
Interestingly, the latter ones are all exception all from up and midstream
regions. Samples of the first class have a mean of 7.87 mg/l, second class samples
a mean of 28.27 mg/l and the Chaliyar samples contain on an average 84.44 mg/l.
Comparison of the TSS values from upstream to downstream no regular behaviour
in the pre-monsoon samples, but the monsoon samples show an increasing amount
of TSS in the flow direction. The content of particulate organic carbon (POC)
ranges between 1.92 and 34.26% of the suspended matter or between 0.29 and 6.23
mg/C/l. These values are in the range of 0.5 up to 40% POC described by MEYBECK
(1982), but two samples have POC contents of 34.26 and 23.76% respectively.
These tow samples were taken in or behind reservoirs in the dry period with low
fresh water input with high biological production. Assuming that 59% of organic
material is made up by carbon (MEYBECK, 1982) this would mean for reservoir
sample that 70% of the TSS has an organic origin. DOC measurements was done
only on the samples of the second and third field trip. Since no stations were
repeated it is not possible to see seasonal fluctuations on DOC-content. The total
amounts range between 0.51 and 37.29 mg/l. The monsoon samples range between
0.5 mg/l and 6.23 mg/l with a mean of 2.20 mg/l. The lowest pre-monsoon sample
has a value of 2.11 mg/l, the whole batch has a mean of 10.91 mg/l. The
calculated sediment discharges vary from 14.78* 103t/yr up to 486.32 *103 t/yr
and give sediment yields from 8.67 to 166.38 t/lm2/yr. Load vs. runoff gives no
correlation at all, while the correlation between yields and runoff is not
meaningful but displays at least an increase in the yield with increasing
runoff. Plot of yield against basin area shows an increase of the yield with
increasing basin area but has not a good correlation coefficient. In comparison
with it displays the load vs. basin area plot a very good correlation with
increasing load during increasing basin area and r2 = 0.92.
Analysis and Leaching Experiments on Selected aquifer Soil of Bangladesh Flood Plains and Nepalese Teras for understanding the Arsenic Mobilization in Ground Water
S. Safiullah*, D.P.Khanal, S.M.Tareq and M.M.K. Khan
Department of Chemistry
Jahangirnagar University
Savar, Dhaka
Bangladesh
Analysis of selected samples of ground water, aquifer soil,
surface soil and river sediment of Bangladesh flood plain and Nepalese Teras
for arsenic and iron shows that the presence of iron is preponderant in
relation to arsenic and there is no significant correlation. Leaching
experiments on arsenic containing aquifer soil under various pH and redox
conditions show significantly different rate of release of arsenic from the
solid to aqueous phase. At high pH (1N NaOH) a mixture of glucose and HCHO
gives rise to fast release. At pH 8.5 the initial rate of release under pure
oxygen atmosphere and H402 is much faster than that in a reducing environment
comprising glucose and HCHO. The rate of release in reducing condition is
linear where as in oxidising condition the initial rate is fast which then
slows down considerably over time.
Dissolved Phosphate in the Ganges-Brahmaputra-Meghna River System in the Bengal Basin, Bangladesh and its Flux to the Bay of Bengal
Dilip K. Datta
Environmental Science Discipline
Khulna University, Khulna 9208
Bangladesh
The dissolved phosphate in the Lower
Ganges-Brahmaputra-Meghna (G-B-M) river system, Bengal basin, Bangladesh was
studied during 1991-93 to determine its distribution in the basin and its
annual flux to the Bay of Bengal. The concentration of dissolved PO4-3 varies
from 0.32 to 3.16 æmol.l-1 in the basin. The spatial variation of dissolved
PO4-3 is not conspicuous. However, the concentration of PO4-3 is high during
monsoon and pre-monsoon period and is related to the turbidity of the river.
Dissolved phosphate shows good correlation coefficient with major cations, and
inorganic processes could be dominant in regulating phosphate concentration in
the basin. However, apatite is not a major regulating solid-phase which
controls the concentration of PO4-3 in the basin. The discharge weighted mean
concentration of phosphate in the Lower G-B-M system is higher than the world
average. The river system contributes 105 x 103 t.yr-1 of dissolved inorganic
phosphate into the Bay of Bengal which accounts for about 10% of the total
dissolved inorganic phosphate flux to the world oceans annually. The
concentration of PO4-3 in the Lower G-B-M river system is within the range of
other major South East Asian rivers.
Organochlorine Pesticides in water and sediment of the Tamiraparani River basin, South India
R. Arthur James and R. Ramesh
Institute for Ocean Management,
Anna University,
Chennai - 600 025 INDIA
The environmental contamination by pesticide residues are of
great concern due to their bioaccumulation and persistent nature.
Organochlorine pesticides, HCH (hexachlorocyclohexane) and DDT
(dichlorodiphenyl-trichloroethane) are among the most persistent and globally
distributed organic pollutants. Since the introduction of organochlorine
pesticides in late 1930s the residues of these compounds have been found in
many parts of the World. In India the organochlorine insecticides, DDT and HCH
were used extensively for agriculture and other public health programmes which
accounts nearly 77% of the total consumption. The Tamiraparani river is one of
the perennial river in South India which is fully utilized for agriculture
purpose. Water and bed sediment samples were collected during monsoon and
summer seasons and analysed in GC using Electron Captured Detector (ECD). Based
on our observation, the samples collected during monsoon period carries maximum
loads of HCH and their alpha, beta,gama and delta isomers. The total HCH
concentration in water samples ranged from a minimum level of 70 æg/L to the
maximum level of 900 æg/L. Elevated concentrations observed at 3 locations in
the lower reaches of the basin (Agaram-400 æg/L; Pudukottai-700 æg/L and
Mullakadu-900 æg/L) explains the agricultural drainage canal carries maximum
load directly from the cultivated lands. The average concentration of HCH (600
æg/L) in Tamiraparani basin is significant when comparing with other major
World rivers (Nile, 20 æg/L; major Malaysian rivers, 320 æg/L; Ganges, 2200
æg/L and Yamuna, 660 æg/L). The sediment samples show similar distribution
pattern for HCH compounds. On the other hand the DDT compounds show erratic
distribution throughout the basin. Similarly in urban area (Tirunelveli) as
well as samples collected near Dam and Anaicut such as Tenkasi and Gadana show
higher concentrations due to the influence mainly of water stagnation which
ultimately leaches out and partly due to higher discharge of organic
pollutants. Good positive correlations were observed between finer fractions
and organic matter indicates finer fractions acts as scavenger for discharged
organic pollutants. The distribution pattern of various DDT isomers in sediment
samples are in the following order OP DDD > OP DDE > PP DDD > OP DDT
and PP DDD. The lower concentration of DDT compounds (0.04 æg/g to 0.1 æg/g) in
both water and sediment samples in many places explains the restricted use and
their non degradability. The variation of pesticide transport in the
Tamiraparani river basin is discussed in this paper.
Red River System and its Water and Sediment Quality
Pham Van Ninh, Nguyen Vu Tuong, Pham Thi Minh Hanh
Center for Marine Environment Survey
Research & Consultation
224 Doi Can Stress, Ba Dinh
Hanoi, Vietnam
Red river system (RRS) is the biggest one in the North
Vietnam. Its total basin area is 154,720 km2 with 46% located in Vietnam, the
rest is in China and Laos. RRS consist of 4 main rivers: Thao, Da, Lo and Hong.
The total length of Red River (RR) consists of Thao and Hong RIvers is 1,126 km
which 510 km is in Vietnam territory. RRS has 3,630 m3/s discharge, total water
volume is 114 km3. Every year RRS discharge 114 million tons alluvia to the sea
ranging from 1000 g/m3 int the delta to 1700-3000 g/m3 in the upstream area.
RRS is in a complicated geomorphologic region. Above 90% of RRs catchment
(RRSCA) are high land and mountains. 70% of this area is higher than 500m. The
elevation decreases in NW- SE direction, towards the Gulf of Tonkin. RRSCA is
under the influence of South East Asian Monsoon. The rainfall is 3000mm/year at
upstream area to 1700-1800 mm/year in the delta. The forest covers now 20.7% the
RRSCA. In RRSCA in the Vietnam territory there are 17,781,700 persons with the
main urben areas as Hanoi (1,087,000 persons), Viet Tri (185,000), Nam Dinh
(220,000), Ha Dong (100,000) and the most important industrial centers in the
North Vietnam. The Cu and Zn in the marine water are of 0.0127-0.0813 mg/l and
0.011-0.092 mg/l respectively. These values are over the allowed ones for
aquaculture. The other heavy metals are still under the standards. Nutrients
are of quite high values for the river water. Entering the estuary region it
become smaller by mixing with the sea water and by sedimentation. The
concentration of contaminants in sediment of the Red river is studies very
little due to no standards in Vietnam for comparison. However in the framework of
the KT.03.07 project some sampling and analiysis have been made. In January and
October 1993, sampling have been made for the Hong River and its coastal zone.
Concentration of Ni, Cr, Cu, Pb, Cd, Zn, As, Hg, PO43-, NH4+, NO2-, NO3-, SiO2
at a number of sites was defined.
Trace Metal Contamination in Thai Rivers
M. Hungspreugs and W. Utoomprurkporn
Department of Marine Science
Chulalongkorn University
Bangkok 10330, Thailand
A review is made of the trace metal contamination in the
three major rivers of Thailand, namely, the Chao Phraya, the Mae Klong and the
Bang Pakong. So far, the most contaminated was the Chao Phraya due to the dense
population along the lower Chao Phraya Basin. The flow of these rivers are
regulated by some dam reserviors or water gate with result in the modification
of the water chemistry, a considerable area of the country in the northeast is
the basin of several tributaries of the Mekong River but it is not considered
here because the Mekong enters the sea through Cambodia and Vietnam further
south.
The effect of land use and hydrological alteration to the river water quality : the Brantas river, East Java, Indonesia
Seno Adi
BPP Technology
Jakarta, Indonesia
The current data set show that significant changes in
discharge between wet and seasons as occurred only in 1992 where the discharge
were 4 times higher than the other years. The BOD and COD did not change among
sampling sites with lower concentration in rainy season (November) 1992. There
is a significant increase at J. Demangan (after Ledoyo dam). Distribution of
BOD and COD showed increased pollution loads in relation to the discharge trend
as in seen in November 1992 and 1997. The effect of reservoirs are visible in
nutrient NH4 reduction only when the concentration is high. BOD and COD was
significantly affected by discharge rates, the higher the discharge the larger
their pollution load. It indicated that the higher precipitation could flush
out the domestic water into the river. BOD and COD in the urban vicinity are
showed relatively low, but with increase in discharge (about 6 times in this
case) these parameters increase drastically too. Almost all the nutrients were
high and showed large fluctuation especially NH4, NO2 P total, but did not vary
much discharge.
The hydrological structure and cycle of carbon, nitrogen in Mekong delta - South of Viet Nam
Nguyen Tac An and Vo Duy Son
Institute of Oceanography
Nha Trang
Viet Nam
Hydrological structure revealed a dominant plume running far
away from river mouth and prolonged toward the Southern. The lack of grazing
was the reason of high production of phytoplankton which appeared in the plume.
The sudden decrease of chlorophyll, which occurred at the fringe of front was
estimated as high grazing rate of zooplankton. Some domains in which the risk
of eutrophication was predicted by model of principal components analysis in
combining with mapping and regressive model.
Biogeochemical Studies in Lesser Himalayan Lakes (Mansar and Surinsar, Jammu District), India
Brijraj K. Das*, Petra Schafer** and Tim Jennerjahn**
* Centre of Advanced study in Geology,
Panjab, University,
Chandigarh 160014,India.
** Institute of Biogeochemistry and
Marine Chemistry,
University of Hamburg,
Bundesstrasse 55, D-2000,
Hamburg 13, Germany
The sediment cores of Mansar and Surinsar lakes of Jammu,
have been investigated for their biogeochemistry. The study revealed that C/N
ratio supported by d 13C values represent the primary source of organic carbon
derived from terrestrial vescular land plants. The poor total nitrogen content,
low AA/AS ratios, low AA-C and AA-N% and lighter d 15 N% suggest terrigenous
organic matter higher in lignin or carbohydrate contents. The variation in the
organic carbon and total nitrogen content in the cores is related to
fluctuation in rainfall and changes in climatic conditions (arid drying)
through time. The variation in the rate of sedimentation in the Mansar based on
Pb210 estimation gives higher 10 mm/yr in the northern flank and 7.7 mm/yr in
the southern and 7.2 mm/yr in Surinsar lake which also contribute in the input
of terrigenous organic matter to the lake sediments.
Sediment Processes in the Estuarine Turbidity Maximum
Mohanachandran G. Menon* and Denise J. Reed
Louisiana Universities Marine Consortium (LUMCON)
8124, Highway 56,
Chauvin, Louisiana-71344, U.S.A.
The sediment processes in Hudson and Columbia River
estuaries are discussed to understand the turbidity maximum formation. One of
the turbidity maxima in the Hudson River estuary is formed by resuspension of
the bed materials by tidal events combined with changing channel bottom
topography. Lagrangian sampling was employed in the Hudson River estuary to
understand the sediment resuspension patterns on a spatial scale. The turbidity
maximum in the Columbia River estuary exists due to tidal forcing and eulerian
sampling mode was attempted to study the sediment suspension on a temporal
scale. Primary particle size distribution (enrichment of fines) in the Hudson
estuary is reflective of hydrodynamic sorting and entrapment of coarser
particles by the Troy Dam in the upstream. In the Columbia River estuary, a
hysterisis between maximum suspended sediment concentration (SSC) and peak
tidal range is observed during the neap-spring transition. Variations in
resuspension intensities and aggregation patterns in the Columbia River estuary
compared to other world estuaries are probably due to the coarser nature of the
particles in the estuarine turbidity maximum. Conceptual models are proposed to
explain sediment processes in the Hudson and the Columbia River estuaries.
Biogeochemistry of the Mangrove Forests
AL. Ramanathan
Department of Geology,
Annamalai University
Annamalai Nagar, Chidambaram,
Tamil Nadu -608 702, India
Mangroves are, on a global scale, exposed to many single
destructive events. They often die a slow death, a process that sometimes lasts
for many year and goes largely unnoticed. The commutative effects of natural
disasters, clear- cutting over logging, fish and reclamation as well as fragmentation
threaten their continued existence with increasing urbanisation and
industrialisation, coastal areas of all tropical littoral countries have been
subjected to considerable environmental stress. Factors which can effects these
areas are: - deforestation, oil spills, domestic swage and industrial effluence
s heavy metals, pesticides,. mining activity and herbicides. There is a little
doubt that petroleum and its by products can be harmful to mangroves because of
their toxic nature. Presumably damage from oil spills to mangroves result from
mechanical clogging of lenticles and air hoots of prop roots and
pneumatophores. A spray of mixed sea water and oil blown into leaves cause more
damage third the spill itself. Phizo phora was found to be more resistant to
oil spill than Avicannia (Jagtap & Untanwale, 1980). Domestic sewage and
industrial effluents contain almost all possible source in pollution to any
Marine area. There discharge causes reduction in species diversity and
sometimes reduction in productivity and affects the nursery grounds for
fishers. So knowledge on heavy metal pollution in mangroves is very important
which throws light on the degree and sources of metal pollution, transport,
fate and bioavailabnilith of the metals concerned. Information on this line in
mangroves in scarce, because no natural or background data on heavy metal
levels/value one available. In recent year for studies were attempted in this
line. Tam & Wang observed low heavy metal come in the sediments in the sea
ward regions, most of them were not extractable, and therefore assume to be non
bioavailable, except the occurrence of few hotspots of excess concentration of
metals dumped by local construction, industry, tourist domestic dumping and
metal wastes. In Pichavaram, metal enrichment in mangroves in 4-5 times greater
than adjacent estuarie and coastal sediments. In Brazil also higher
accumulation of metals in mangroves is observed earlier. Thus the mangrove
sediments acts as trap/sink or filter for the heavy metals and simultaneously
released into the water and biologic system and food chains, which may affect
the entire survival of the total mangrove forest (eg.) Aquatic Farm and Flora
in the mangrove are affected alike by Cd. 10ppm of Cd is sufficient to kill
fishes in one day, 2ppm of Cd take 10 days. Hard water afford protection
against the harmful affects of Cd. Increasing salinity also reduces the Cd
toxicity, but Cd is Less toxic to plants than methyl mercury or Cu, but is
similar is toxicity to Pb, Ni, and Cu (Tam et. al., 1995). For mangrove plant
Cu and Pb are essential in lower Qualitative and toxic is excess, where as Pb,
and Cd are not at all needed and are toxic to the plants. Depended on the
anthropogenic level of contamination their environmental status are predicted.
Biogeochemical Characteristics of the Everglades Sloughs
Panchabi Vaithiyanathan* and Curtis J. Richardson**
** Wetlands Center, School of the
Environment, Duke University, Durham, NC 27706
* Corresponding author at: Duke
University Wetlands Center Everglades Field Station,16139 Okeechobee Blvd.,
Loxahatchee, FL 33470.
Everglades sloughs are alkaline hardwater systems. Water
column dissolved phosphate (5 æg/L) and TP (9 æg/L) concentration in the
sloughs are typical of oligotrophic waters. Molar ratios of dissolved inorganic
nitrogen and phosphorus (DIN: DIP = 28:1) in the surface waters suggest that P
may be limiting the aquatic primary productivity in the Everglades sloughs.
Variations in water column TP and TN in the sloughs were inversely related to
the water depth fluctuations (p<0.0001) suggesting the strong link between
hydrology and nutrient regime in the Everglades. Periphyton and macrophytes in
the sloughs exhibited N:P ratios indicative of depletion in P relative to N.
The N:P ratios in the Everglades slough communities were in the very upper
range of values reported for aquatic plants from other ecosystems. The N:P
ratios in periphyton were higher than macrophytes suggesting that the extent of
P depletion was even greater for periphyton. As a result any introduced
inorganic phosphate was taken up rapidly by the periphyton reducing the water
column PO4- P to near background levels. Our results suggest that C:N:P ratios
of the periphyton provide a reliable measure of the P-status of the Everglades
sloughs whereas the water column P concentration may not truly reflect the
P-status of the system. In addition to regulating the water column P
concentration the periphyton mat also plays an important role in oxygenating
the water column of the sloughs. Experimental results show that a decline in
periphyton mat cover will result in a significant decrease in the water column
dissolved oxygen concentration and may also lead to other ecosytem changes by
enhancing the PAR availability to the slough bottom. The integrity of the
periphyton mat is therefore crucial to the protection of the Everglades slough
community.
Methane Emission from Coastal Wetlands of India
R.Ramesh and G.R. Purvaja
Institute for Ocean Management,
Anna University,
Chennai 600 025, India
Wetlands are the largest natural source of methane (CH4)
accounting for about 20% of the total global annual emissions. The increased
atmospheric CH4 concentration for the last several hundred years are primarily
due to human activities, whereas pre-industrial sources of methane were
primarily due to natural sources. There are considerable differences in
emission rates from different types of wetlands mainly due to the complexity in
ecology and partly due to anthropogenic disturbances. In this paper, the
emission of CH4 from different coastal wetlands of South India have been
measured throughout the year. Monthly variations in CH4 emissions showed
distinct trends in the unpolluted coastal wetlands (0.52 to 20.30 mg m-2 hr-1)
than in polluted wetlands (1.91 to 45.97 mg m-2 hr-1). Several environmental
forcing factors such as temperature, salinity, sulphate, organic matter,
oxygen, substrate, etc., in addition to human additions were found to control
methanogenesis and its emission to the atmosphere. A clear decline in
emissivity characteristics could be noted in these coastal wetlands due to the
influence of salinity and sulphate which inhibited methanogenesis in these
environments. However, due to diverse human activities the CH4 emission is
almost double in polluted wetland sites. Based on the Se observations, CH4
emission from coastal wetlands along the Indian coastline has been computed
(0.68 to 13.06 x 109 g m-2 yr-1).
Matter Transfer in a land-shelf-basin system : NW Aegean area - Mediterranean Sea
Anagnostou, Ch., Kaberi, E., Karageorgis, A.,
Kontogiannis, H., Krassakopoulou, E., Pagou, K., Pavlidou, A. &
Stavrakakis, Sp.
National Centre for Marine Research (NCMR),
Ag. Kosmas, 16604 Ellinikon, Greece
The dynamic processes of the matter transfer are studied in
a Mediterranean land- shelf-basin.In this system an extended drainage area of
55.5 x 103 km2 with major and small rivers as well as ephemeral streams,
influences the transfer of matter in the marine environment. The total annual
discharge is estimated in 10.2 x 106 m3 of water and the catchment area could
represent a sediment supply of the order of 3-4 x 106 tonnes/year. The
deposition of the sediment load discharged by rivers results in a deltaic
accretion of the order of 1.0 - 1.3 km2/year. Sediments are accumalated on the
shelf of the order of 2.17 x 106 tonnes/year, and in the basin 0.3 x 106
tonnes/year, indicating the role of the shelf-plateau as a natural sediment
trap . On the shelf 70,000 tonnes/year of C are buried whereas in the basin
only 13,500 tonnes/year of C.
Dissolved Load of a Central Himalayan Forest Headwater
M.S. Rawat,
Kumaun University,
Nainital, U.P. India.
Martin J. Haigh,
Oxford Brookes University,
Oxford, England.
Josef Krecek,
European University,
Prague, Czech Republic.
J.S. Rawat,
Kumaun University,
Almora, U.P. India.
This report examines climatological and hydrological data
collected at Animal Park Experimental Catchment, Almora, U.P., between 1989 and
1995. Preliminary geochemical tests yield results that may be fairly typical
for a relatively undisturbed forest headwater. This is a near neutral pH, high
conductivity (K25/uS/cm) stream. Base flow concentrations of Ca2+, K+ and Mg2+
are relatively low for the region, as is sulphate. Nitrate and ammonia show
peaks that may be related to land management activity. The proportion of
dissolved to suspended load is high (1.27:1). It may be that the construction
of check-dams in the later 1970s has shifted the Physical/Chemical Load ratio
by trapping sediment within the basin. Statistical analyses show that suspended
and bed-load sediment transport are strongly correlated with runoff and hence
that they are transport-limited. By contrast, dissolved load transport is
supply limited. Dilution effects create a negative relationship with runoff and
positive relationship with evaporation.
Redox Reactions in Ground Water Environment : Selected Examples
B.C. Raymahashay
Department of Civil Engineering,
Indian Institute of Technology,
Kanpur - 208016.INDIA.
Redox reactions exert major controls on the occurrence of
nitrate, chromate and arsenate in ground water. Nitrate levels can be lowered
by denitrification in the presence of soil biota or by electron donors like
pyrite in deep aquifers. Cr(VI) and As(V) species, on the other hand, are
strongly adsorbed an positively charged surfaces of iron hydroxide minerals.
However, their retention is affected when competing anions are supplied through
increase ln salinity or fertilizer application.
Dimensions of Mercury Menace to-day
Sachinath Mitra
Department of Geological Sciences,
Jadavpur University,
Calcutta - 700032, India
In the world today the total load of mercury emissions is
about 6 to 7.5 thousand tonnes per year. The emission due to human civilisation
got a spurt since the days of gold and silver rush since the sixteenth century.
The effluents carrying mercury ultimately unloads it in lakes and seas. Fish
containing the biomethylated mercury poses as the major source of mercury
contamination in man, who is under increasing toxicological pressure from other
adverse eco-components as well. The factors controlling mercury contamination
in aquatic environment and the load generated in the fish-eating population
have been shown with response to dose- response relationship and the WHO
prescribed limits.In this paper an analysis has been attempted to focus on the
major causative factors of mercury contamination through human activities. An
evaluation of the recent activities such as construction of dams for hydroelectric
power generation, impoundment for other water reservoirs, cutting new lakes,
deforestation and erosion of forest soil enriched in toxic metals has been
attempted with notes on the flood perturbation of the eco- stability. An
overview has been made of the salient aspects accelerating the processes of
methylation in the present day ecosystem.
Environmental Pollution in Andhra Pradesh
K. Shivkumar
Department of Atomic Energy, Atomic Minerals Directorate for
Exploration and Research
Civil Lines,
Nagpur - 440 001, INDIA
Andhra Pradesh state accounts for 8% of country s population
and hosts same percentage of forest cover. Industrial growth, urbanization has
increased several folds since past four decades. Major industries such as
power, pharmaceuticals, paper, cement, sugar, iron and steel, chemicals,
fertilizers, textiles etc in Government and private sectors contributed to the
states economy and improved the standard of living of the people. The
industrial growth has compelled to over exploitation of natural resources such
as forest products, mining of minerals including coal, limestone, iron ores,
bauxite, base metals, barytes, slates and also led to the over utilization of
water resources. Explosion of population by two times since the formation of
the state had increased the stress on agriculture sector, which forced to
invade the forests, converting them into agricultural fields. Forest cover has
diminished to bare 43,000 sq.km area. Over exploitation followed by industrial
development had polluted air, water, and soil. Increased vehicular traffic in
urban areas such as twin cities, Vizag, Vijayawada etc. has polluted air due to
smoke and particulate emissions. Water pollution is mainly due to discharge of
untreated industrial effluents, in streams, tanks, rivers, lakes and ocean.
Dumping of municipal waste, over drafting of ground water, seawater intrusion,
and soil erosion have also increased the level of pollutants in various water
bodies. Recent growth in shrimp culture had unbalanced the entire coastal
ecosystem causing a permanent damage.
Pollution due to Exploitation of Mineral Resources
G.J.Chakrapani
Department of Earth Sciences,
University of Roorkee,
Roorkee 247667 (U.P.),India
A.K.Soni
Central Mining Research Institute,
Regional Centre, CBRI Campus,
Roorkee - 247667 (U.P.), India
Mineral resources are an integral part of any country s
economic potential. There has been mining activity since civilisation started
initially for making ammunition for hunting to the present for nuclear power,
hydrocarbons, metals etc. Pollution arising out of the mining activities can
cause serious damage to the environment, unless of course remedial measures are
taken. This paper discusses the various types of environmental pollution caused
by exploitation of mineral resources. Physical and chemical pollution caused
due to mining are illustrated with three case studies
Metal Concentrations in Coral Skeletons as an Indicator of Industrial Pollution in Tuticorin Group of Islands, Gulf of Mannar, India
N. Ramanujam and M.V. Mukesh
Post Graduate Department of Geology and Research Centre
V.O. Chidambaram College,
Tuticorin -628 008, Tamil Nadu, India
Incorporation of heavy metals in coral skeletons is a
reliable indicator of industrial pollution in the marine environments. Coral
colonies of Montipora digitata, Montipora foliasa, Montastrea annularis,
Acropora hycinthus, Pocillopura damicornis, Acropora cervicornis and Acropora
nobilis were collected in the reef areas of Tuticorin group of islands. Metal concentrations
determined by Sequential Plasma Emission Spectrometer reveal that higher
concentration of Sr and other metals like Zn, Fe, Ti, Cu, Mo, Cr, Ni, Hg, Sn, V
and Cd are in decreasing concentrations in the coral skeletons. These metal
concentrations in the coral skeletons are many folds than the concentrations of
heavy metals in standard sea water. Presence of strontium in coral skeleton
inhibits alteration of aragonite to calcite. Concentrations of other metals in
the individual coral species are ranging from 0.098 ppm (Acropora hyacinthus)
to 0.90 ppm (Montipora digitata). Coral species are bio-indicator and
concentrations in the species are relevant to public health and pollution
concern. In the study area the marine pollution is traced to fly ash content of
Thermal Power Plant and other effluents discharging from chemical industries.
Conservation of Freshwater Bio-diversity : Policy and programmatic options for developing countries
Biksham Gujja
Manager Freshwater Programme,
WWF-International
Gland, Switzerland
Conservation of freshwater ecosystems is paramount
importance to all the developing countries. In future in many countries, the
most important and visible gains made in meeting basic needs - drinking water
requirements, establishing basic health facilities and food security could be
wiped out if the freshwater ecosystems are continued to degrade at the present
rate. Many developing countries are facing two pronged challenges in conserving
the freshwater ecosystems. First the present understanding about the properties
need to be revised. Primarily that the conservation freshwater ecosystems are
not the priority of poor countries has they need to work on improving the basic
needs of the people and then they can work on improving the status of the
ecosystems. This has to be fundamentally corrected. Conservation of freshwater
ecosystems has to be made integral part of meeting basic needs. Second, the
general understanding that conservation is expensive and technical business.
Some extent it is true but many developing countries do already have human and
technical resources. They simple need to revive some of the water management
systems, which were time tested but adopt to suite the present socio-economic
situation. The future of the freshwater conservation in some of these countries
depends on the extent they integrate the freshwater management at the basin
level and treating water as finite resources which has implications to
economic, social and environmental status of the country. Proper policies and
institutions have to be placed at appropriate level to deal with emerging
freshwater crisis.
Nutrients and organic matter of some tropical rivers, southwest-Nigeria
O. Martins*, V. Ittekkot** and A.O. Idowu*
* College of Environmental Resources Management,
University of Agriculture,
Abeokuta, Nigeria
** Institute of Biogeochemistry and
Marine Chemistry, University of Hamburg, Germany
Samples taken from twelve rivers , each draining in N-S
direction into the Atlantic Ocean via the Lagos and Lekki Lagoons were analysed
for their biogeochemical parameters. The southwestern part of Nigeria
represents an area with a high population density, where surface waters are
used as vehicle of domestic and industrial wastes. However, most of these
rivers also serve as important sources of water supply: the Ogun river, for
instance, supplies the sprawling city of Lagos (11 million inhabitants) with
water from the Oyan dam, located 60 km northwards. The rivers under
investigation are characterised by low relief with a N-S gradient; they all
take their sources from a NW-SE striking escarpment at an elevation of about
500 m in the north-west, but slightly lower in the south-east. Three vegetation
zones can be identified in the study area : the savannas are well- marked
against the high forest vegetation in the central and eastern sector of the
area. Extensive natural forests and forest reserves have disappeared due to
rapid urbanization. Swamp and mangrove forests cover the southern coastal and
riverine areas adjacent to the lagoons. The rivers were sampled during the
flood period when discharges were some 25 to 100 times the dry season values.
The paper dicusses results of the dissolved nutrients, including nitrates,
phosphates and silicates, as well as the particulate organic matter.
Contact
Prof. V. Subramanian
Tel. : +91-11-6107676. Ext. 2316 School of Environmental Sciences
Telefax : +91-11-6106501 Jawaharlal Nehru University
Fax : +91-11-6165886, 6172438 New Delhi - 110 067, INDIA