shikha panwar | Gurukul Kangri University (original) (raw)
Papers by shikha panwar
The present study was aimed at the assessment of forest cover and land use changes in the catchme... more The present study was aimed at the assessment of forest cover and land use changes in the catchment area of Bhimtal lake situated in the Kumaun region of Uttarakhand, India using multitemporal Landsat satellite images. The Landsat satellite images of year 1996 to 2015 were acquired and subjected to supervised classification into four different classes viz. urban, agriculture, forest and water body. The classified maps were verified through random field samples and google earth imagery. The images of study area were categorized into four different classes viz., settlement area, agriculture area, forest area and water body. The results revealed that during last 20 years, the settlement area has been increased from 9.70% to 18.38%, agricultural area has increased from 44.32% to 47.63% and forest area has been decreased 43.58% to 31.47%. The findings from the study will be useful for lake and landscape planning and can serve as a potential source of information to the policy makers of Uttarakhand.
Bhimtal Lake situated in Uttarakhand, India, and has been devastated due to anthropogenic activit... more Bhimtal Lake situated in Uttarakhand, India, and has been devastated due to anthropogenic activities. In this study we examined the diversity and distribution pattern of zooplanktons in the Bhimtal Lake, along with evaluation of the relationships among different zooplankton groups and abiotic factors during the period September, 2013 to August, 2014. Sampling was done seasonally, during summer, winter and monsoon seasons, at three sites in Bhimtal lake. Sample analysis revealed the presence of 29 species of zooplankton including 16 species of Rotifers, 8 species of Cladocera and 5 species of Copepods. Rotifera group was the most dominant among all three groups. Positive co-relation was found between zooplankton growth with water temperature and pH while, there growth was adversely affected with increasing alkalinity, nitrates and dissolved oxygen. The diversity of Rotifers, Cladocera and Copepods were highest during summer, and was lowest during winter, while their density and biomass were found to be highest at the surface water during summer. It can be stated that the tropic nature of Bhimtal Lake may have been changed to mesotrophic conditions.
Abstract: A study was conducted to determine the vertical variations in physico-chemical characte... more Abstract: A study was conducted to determine the vertical variations in physico-chemical characteristics of
Bhimtal Lake at Uttarakhand during January to December 2013. Various physico-chemical parameters like water
temperature, pH, dissolved Oxygen (DO), biochemical Oxygen Demand (BOD), chemical Oxygen Demand (COD),
salinity, nitrate and phosphate were monitored along the vertical ecological gradient, to determine trophic variations
in three selected sites in lake. Vertically observed values showed that water temperature decreased with depth
25.80 to 20°C and 16.7 to 10.5°C in summer and winter season respectively, pH was observed alkaline in range,
Dissolved oxygen was observed vertically 7.88 to 6.50mg/l in summer and 8.34mg/l to 6.15mg/l in winter season,
BOD and COD values were showed increasing trends during summer season. The nutrients were accumulated in
lake water from many sources from its catchment basin of Bhimtal lake, hence nitrate and phosphate were
observed 0.068 to 0.041 mg/l, and 0.019 to 0.046mg/l in summer respectively. The physico-chemical values of
water temperature, pH and DO showed a declining trend while and BOD, COD, EC, salinity, nitrate and phosphate
showed a relative increase along the depth of water in Bhimtal lake. The water quality of Bhimtal lake showed a
degrading drift resulting from various anthropogenic activities and results revealed that nutrients pollution loads
were quite higher in summer season in Bhimtal lake.
Key words: Bhimtal lake, Water Quality, Physico-chemical characteristics, Nutrients
Abstract: Climate change is recognized as a threat on ecosystem productivity of lakes. Climatic v... more Abstract: Climate change is recognized as a threat on ecosystem productivity of lakes. Climatic variation affects
the hydrological, physico-chemical and biological characteristics of lakes. Climatic change will make future efforts
to change the water quality and its trophic status of lakes and wetland ecosystem. Impacts of global warming on
lakes include an extended growing period at high latitudes, intensified stratification and nutrient loss from surface
waters, decreased hypolimnetic oxygen (below the thermocline) in deep, stratified lakes and expansion in range
for many invasive aquatic weeds. Direct effects of climate change on lakes includes changes in temperature,
water level, pH, concentration of dissolved gases (dissolved oxygen, free carbon dioxide, ammonia etc.). Elevated
temperatures would decrease oxygen solubility and increase the rates of microbial oxygen demand, both leading
to a decrease in dissolved oxygen available for biotic communities in different trophic level of lake ecosystem.
Climate changes are increasingly recognized as important regulatory factors to assess the primary productivity in
relation to distribution changing pattern of biotic communities (phytoplankton, zooplankton aquatic birds and fish
species) in the lake ecosystem. The remedial measures for regulate the impact assessment of climate change on
lake ecosystem are required scientific attentions on national and international environmental forums.
Key words: Climate Change, Ecosystem productivity, Lake, Aquatic Biodiversity
Climate changes are recognized as important environmental regulatory factors to assess the primar... more Climate changes are recognized as important environmental regulatory factors to assess the primary productivity in relation to changing pattern of abiotic and biotic characteristics in lake ecosystem. Bhimtal Lake is the largest lake approximately 85.26 ha among all Kumaun lakes in Uttarakhand. The comparative data of last twenty years of Bhimtal lake catchment basin revealed that air temperature has been increased 1.5 to 2.1 °C in summer, 0.2 to 0.8 °C in winter, relative humidity increased 4-6% in summer and rainfall pattern changed erratically in rainy season. The surface water temperature of lake showed an increasing pattern as 0.8 to 2.6 °C, pH value decreased 0.2 to 0.5 in winter and increased 0.4 to 0.6 in summer and dissolved oxygen level showed a decreasing trend as 0.4 to 0.7 mg/l in winter. The lake ecosystem productivity mainly depends upon the phytoplankton species composition and their biomass as primary producers in the food web cycle. The changing pattern of phytoplankton indicated that biomass of Chlorophyceae and Bacilleriophyceae families were decreasing as 1.99 and 1.08% respectively in Bhimtal lake. The biomass of Cynophyceae was increasing as 0.45% and contributing the algal blooming in summer season. The phytoplankton species composition exhibited their correlationship with pH, water temperature, dissolved oxygen and other nutrient parameters of lake water. The present research paper emphasized on the effects of climatic variables on phytoplankton biomass in Bhimtal lake of Kumaun region. The present research will be contributed significantly to assess the current change status of ecosystem productivity of Bhimtal lake with different time scale.
Bhimtal is a mesotrophic lake and the sediments acted as a sink or trap of nutrients in the botto... more Bhimtal is a mesotrophic lake and the
sediments acted as a sink or trap of nutrients in
the bottom of lake. The water quality and
volume of Bhimtal Lake has showed a
degrading trend due to very rapid settlement,
constructions and encroachment on lake
catchment basin or hills by human habitation
beyond its carrying capacity. The bathymetric
mapping of the lake showed that the maximum
depth of Bhimtal Lake was recorded only
20.9m on south-west from the middle island
point. The sedimentation rate in three zones of
Bhimtal Lake ranged from 0.27 to
1.05mm/year. The rates of sediments showed
higher trend in the mallital zone compared with
Keywords: Bhimtal lake ⏐ Bathymetric ⏐
Sedimentation ⏐ Land use pattern
The present study was aimed at the assessment of forest cover and land use changes in the catchme... more The present study was aimed at the assessment of forest cover and land use changes in the catchment area of Bhimtal lake situated in the Kumaun region of Uttarakhand, India using multitemporal Landsat satellite images. The Landsat satellite images of year 1996 to 2015 were acquired and subjected to supervised classification into four different classes viz. urban, agriculture, forest and water body. The classified maps were verified through random field samples and google earth imagery. The images of study area were categorized into four different classes viz., settlement area, agriculture area, forest area and water body. The results revealed that during last 20 years, the settlement area has been increased from 9.70% to 18.38%, agricultural area has increased from 44.32% to 47.63% and forest area has been decreased 43.58% to 31.47%. The findings from the study will be useful for lake and landscape planning and can serve as a potential source of information to the policy makers of Uttarakhand.
Bhimtal Lake situated in Uttarakhand, India, and has been devastated due to anthropogenic activit... more Bhimtal Lake situated in Uttarakhand, India, and has been devastated due to anthropogenic activities. In this study we examined the diversity and distribution pattern of zooplanktons in the Bhimtal Lake, along with evaluation of the relationships among different zooplankton groups and abiotic factors during the period September, 2013 to August, 2014. Sampling was done seasonally, during summer, winter and monsoon seasons, at three sites in Bhimtal lake. Sample analysis revealed the presence of 29 species of zooplankton including 16 species of Rotifers, 8 species of Cladocera and 5 species of Copepods. Rotifera group was the most dominant among all three groups. Positive co-relation was found between zooplankton growth with water temperature and pH while, there growth was adversely affected with increasing alkalinity, nitrates and dissolved oxygen. The diversity of Rotifers, Cladocera and Copepods were highest during summer, and was lowest during winter, while their density and biomass were found to be highest at the surface water during summer. It can be stated that the tropic nature of Bhimtal Lake may have been changed to mesotrophic conditions.
Abstract: A study was conducted to determine the vertical variations in physico-chemical characte... more Abstract: A study was conducted to determine the vertical variations in physico-chemical characteristics of
Bhimtal Lake at Uttarakhand during January to December 2013. Various physico-chemical parameters like water
temperature, pH, dissolved Oxygen (DO), biochemical Oxygen Demand (BOD), chemical Oxygen Demand (COD),
salinity, nitrate and phosphate were monitored along the vertical ecological gradient, to determine trophic variations
in three selected sites in lake. Vertically observed values showed that water temperature decreased with depth
25.80 to 20°C and 16.7 to 10.5°C in summer and winter season respectively, pH was observed alkaline in range,
Dissolved oxygen was observed vertically 7.88 to 6.50mg/l in summer and 8.34mg/l to 6.15mg/l in winter season,
BOD and COD values were showed increasing trends during summer season. The nutrients were accumulated in
lake water from many sources from its catchment basin of Bhimtal lake, hence nitrate and phosphate were
observed 0.068 to 0.041 mg/l, and 0.019 to 0.046mg/l in summer respectively. The physico-chemical values of
water temperature, pH and DO showed a declining trend while and BOD, COD, EC, salinity, nitrate and phosphate
showed a relative increase along the depth of water in Bhimtal lake. The water quality of Bhimtal lake showed a
degrading drift resulting from various anthropogenic activities and results revealed that nutrients pollution loads
were quite higher in summer season in Bhimtal lake.
Key words: Bhimtal lake, Water Quality, Physico-chemical characteristics, Nutrients
Abstract: Climate change is recognized as a threat on ecosystem productivity of lakes. Climatic v... more Abstract: Climate change is recognized as a threat on ecosystem productivity of lakes. Climatic variation affects
the hydrological, physico-chemical and biological characteristics of lakes. Climatic change will make future efforts
to change the water quality and its trophic status of lakes and wetland ecosystem. Impacts of global warming on
lakes include an extended growing period at high latitudes, intensified stratification and nutrient loss from surface
waters, decreased hypolimnetic oxygen (below the thermocline) in deep, stratified lakes and expansion in range
for many invasive aquatic weeds. Direct effects of climate change on lakes includes changes in temperature,
water level, pH, concentration of dissolved gases (dissolved oxygen, free carbon dioxide, ammonia etc.). Elevated
temperatures would decrease oxygen solubility and increase the rates of microbial oxygen demand, both leading
to a decrease in dissolved oxygen available for biotic communities in different trophic level of lake ecosystem.
Climate changes are increasingly recognized as important regulatory factors to assess the primary productivity in
relation to distribution changing pattern of biotic communities (phytoplankton, zooplankton aquatic birds and fish
species) in the lake ecosystem. The remedial measures for regulate the impact assessment of climate change on
lake ecosystem are required scientific attentions on national and international environmental forums.
Key words: Climate Change, Ecosystem productivity, Lake, Aquatic Biodiversity
Climate changes are recognized as important environmental regulatory factors to assess the primar... more Climate changes are recognized as important environmental regulatory factors to assess the primary productivity in relation to changing pattern of abiotic and biotic characteristics in lake ecosystem. Bhimtal Lake is the largest lake approximately 85.26 ha among all Kumaun lakes in Uttarakhand. The comparative data of last twenty years of Bhimtal lake catchment basin revealed that air temperature has been increased 1.5 to 2.1 °C in summer, 0.2 to 0.8 °C in winter, relative humidity increased 4-6% in summer and rainfall pattern changed erratically in rainy season. The surface water temperature of lake showed an increasing pattern as 0.8 to 2.6 °C, pH value decreased 0.2 to 0.5 in winter and increased 0.4 to 0.6 in summer and dissolved oxygen level showed a decreasing trend as 0.4 to 0.7 mg/l in winter. The lake ecosystem productivity mainly depends upon the phytoplankton species composition and their biomass as primary producers in the food web cycle. The changing pattern of phytoplankton indicated that biomass of Chlorophyceae and Bacilleriophyceae families were decreasing as 1.99 and 1.08% respectively in Bhimtal lake. The biomass of Cynophyceae was increasing as 0.45% and contributing the algal blooming in summer season. The phytoplankton species composition exhibited their correlationship with pH, water temperature, dissolved oxygen and other nutrient parameters of lake water. The present research paper emphasized on the effects of climatic variables on phytoplankton biomass in Bhimtal lake of Kumaun region. The present research will be contributed significantly to assess the current change status of ecosystem productivity of Bhimtal lake with different time scale.
Bhimtal is a mesotrophic lake and the sediments acted as a sink or trap of nutrients in the botto... more Bhimtal is a mesotrophic lake and the
sediments acted as a sink or trap of nutrients in
the bottom of lake. The water quality and
volume of Bhimtal Lake has showed a
degrading trend due to very rapid settlement,
constructions and encroachment on lake
catchment basin or hills by human habitation
beyond its carrying capacity. The bathymetric
mapping of the lake showed that the maximum
depth of Bhimtal Lake was recorded only
20.9m on south-west from the middle island
point. The sedimentation rate in three zones of
Bhimtal Lake ranged from 0.27 to
1.05mm/year. The rates of sediments showed
higher trend in the mallital zone compared with
Keywords: Bhimtal lake ⏐ Bathymetric ⏐
Sedimentation ⏐ Land use pattern