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11.
Lalthanzara H Ramanujam SN Jha LK 《Journal of environmental biology / Academy of Environmental Biology, India》2011,32(5):599-605
Earthworm population dynamics was studied in two agroforestry systems in the tropical hilly terrain of Mizoram, north-east India, over a period of 24 months, from July 2002 to June 2004. Two sites of agroforestry situated at Sakawrtuichhun (SKT) and Pachhunga University College (PUC) campus, Aizawl, having pineapple as the main crop, were selected for detail studies on population dynamics. Five of the total twelve species of earthworm reported from the state were recorded in the study sites. The density of earthworm ranged from 6 to 243 ind.m(-2) and biomass from 3.2 - 677.64 g.m(-2) in SKT. Comparatively the density and biomass in PUC, which is at relatively higher altitude were lowerwith a range of 0 to 176 ind.m(-2) and biomass from 0 - 391.36 g.m(-2) respectively. Population dynamics of earthworm was significantly correlated with rainfall and physical characters of the soil. Earthworm biomass was significantly affected by rainfall and moisture content of the soil. The influence of chemical factors was relatively less. 相似文献
12.
Soma Giri Gurdeep Singh V. N. Jha R. M. Tripathi 《Environmental monitoring and assessment》2011,175(1-4):157-166
Ingestion of radionuclides and heavy metals through drinking water and food intake represents one of the important pathways for long-term health considerations. Milk and milk products are main constituents of the daily diet. Radionuclides and heavy metals can be apprehended in the ecosystem of the East Singhbhum region which is known for its viable grades of uranium, copper and other minerals. For the risk assessment studies, samples of milk were collected from twelve villages around Bagjata mining area and analysed for U(nat), 226Ra, 230Th, 210Po, Fe, Mn, Zn, Pb, Cu and Ni. Analysis of the results of the study reveals that the geometric mean of U(nat), 226Ra, 230Th and 210Po was 0.021, 0.24, 0.23 and 1.08 Bq l???1, respectively. The ingestion dose was calculated to be 12.34 ??SvY???1 which is reflecting the natural background dose via the route of ingestion, and much below the 1 mSv limit set in the new ICRP recommendations. The excess lifetime cancer risk was estimated to be 1.72 × 10???4 which is within the acceptable excess individual lifetime cancer risk value of 1 × 10???4. The geometric mean of Fe, Mn, Zn, Cu and Ni was 4.91, 0.29, 4.77, 0.56 and 0.48 mgl???1, respectively; whereas the daily intake was computed to be 0.44, 0.03, 0.43, 0.05 and 0.04 mg/day, respectively. Pb was not detected in any of the samples. The hazard quotient revealed that the intake of the heavy metals through the ingestion of milk does not pose any apparent threat to the local people as none of the HQ of the heavy metals exceeds the limit of 1. 相似文献
13.
Manoj Jha Philip W. Gassman Silvia Secchi Roy Gu Jeff Arnold 《Journal of the American Water Resources Association》2004,40(3):811-825
ABSTRACT: The size, scale, and number of subwatersheds can affect a watershed modeling process and subsequent results. The objective of this study was to determine the appropriate level of subwatershed division for simulating flow, sediment, and nutrients over 30 years for four Iowa watersheds ranging in size from 2,000 to 18,000 km2 with the Soil and Water Assessment Tool (SWAT) model. The results of the analysis indicated that variation in the total number of subwatersheds had very little effect on streamflow. However, the opposite result was found for sediment, nitrate, and inorganic P; the optimal threshold subwatershed sizes, relative to the total drainage area for each watershed, required to adequately predict these three indicators were found to be around 3, 2, and 5 percent, respectively. Decreasing the size of the subwatersheds below these threshold levels does not significantly affect the predicted levels of these environmental indicators. These threshold subwatershed sizes can be used to optimize input data preparation requirements for SWAT analyses of other watersheds, especially those within a similar size range. The fact that different thresholds emerged for the different indicators also indicates the need for SWAT users to assess which indicators should have the highest priority in their analyses. 相似文献
14.
Hydrobiological study of lake Mirik in Darjeeling Himalayas 总被引:1,自引:0,他引:1
Jha P Barat S 《Journal of environmental biology / Academy of Environmental Biology, India》2003,24(3):339-344
Some hydrobiological features of lake Mirik, situated in the Darjeeling Himalayas were studied during May to October, 2000. Water temperature showed abrupt fluctuations. The pH was generally acidic. Dissolved oxygen increased steadily with increasing rainfall and recorded highest in late August (12.6 mgl(-1)). The gross primary productivity had a highest value of 87.50 mg C m(-3) hr(-1). Chlorophyceae and Cyanophyceae were identified among phytoplanktons. Zooplanktons were represented by Cladocerans and Copepods. The study revealed higher concentration of nutrients at certain pockets of the lake, which points to increasing human influences in the system, and, the water cannot serve as a scarcity alternative for drinking purpose. 相似文献
15.
Alam Absar Kumar Jeetendra Sarkar Uttam Kumar Jha Dharm Nath Srivastava Saket Kumar Kumar Vijay Das Basanta Kumar 《Environment, Development and Sustainability》2021,23(9):13221-13241
Environment, Development and Sustainability - The present study evaluated the effectiveness of stocking the Gangetic carps, viz. Labeo catla, Labeo rohita, and Cirrhinus mrigala, in a large... 相似文献
16.
Jha Prabhat Rajguru Shivam Parmar Jaydip Shah Manan 《Environmental science and pollution research international》2023,30(1):90-103
Environmental Science and Pollution Research - This paper shows the comparison of the various conventional technologies used for desalination and the advantages of using renewable energy such as... 相似文献
17.
Kirti Avishek Gopal Pathak M. S. Nathawat Usha Jha Neeta Kumari 《Environmental monitoring and assessment》2010,167(1-4):617-623
Fluoride in groundwater is known to contaminate the water sources globally. Jharkhand, one of the states in the eastern part of India, is known to have excessive fluoride content in groundwater sources. The present work involves assessment of water quality with special reference to fluoride in Majhiaon block of Garwa district in Jharkhand. Iron, nitrate and arsenic were also tested for the water samples collected from site. Eight hundred forty samples were tested for fluoride on site using colourimetry method, and one tenth of the samples were brought to laboratory for iron, nitrate, arsenic and fluoride analysis. Results show that 402 samples were having fluoride above permissible limit. Iron and nitrate were found to be beyond permissible limits in 302 and 286 water samples, respectively. More than 50% of samples collected from school had fluoride levels above permissible limits. Arsenic was well within the limits. However, few samples shown were excessive of iron and nitrate. 相似文献
18.
K. R. L. Saranya C. Sudhakar Reddy P. V. V. Prasada Rao C. S. Jha 《Environmental monitoring and assessment》2014,186(5):3283-3296
Analyzing the spatial extent and distribution of forest fires is essential for sustainable forest resource management. There is no comprehensive data existing on forest fires on a regular basis in Biosphere Reserves of India. The present work have been carried out to locate and estimate the spatial extent of forest burnt areas using Resourcesat-1 data and fire frequency covering decadal fire events (2004–2013) in Similipal Biosphere Reserve. The anomalous quantity of forest burnt area was recorded during 2009 as 1,014.7 km2. There was inconsistency in the fire susceptibility across the different vegetation types. The spatial analysis of burnt area shows that an area of 34.2 % of dry deciduous forests, followed by tree savannah, shrub savannah, and grasslands affected by fires in 2013. The analysis based on decadal time scale satellite data reveals that an area of 2,175.9 km2 (59.6 % of total vegetation cover) has been affected by varied rate of frequency of forest fires. Fire density pattern indicates low count of burnt area patches in 2013 estimated at 1,017 and high count at 1,916 in 2004. An estimate of fire risk area over a decade identifies 12.2 km2 is experiencing an annual fire damage. Summing the fire frequency data across the grids (each 1 km2) indicates 1,211 (26 %) grids are having very high disturbance regimes due to repeated fires in all the 10 years, followed by 711 grids in 9 years and 418 in 8 years and 382 in 7 years. The spatial database offers excellent opportunities to understand the ecological impact of fires on biodiversity and is helpful in formulating conservation action plans. 相似文献
19.
Vidyadhar V. Gedam Rajesh Jha Pawan Labhasetwar Christian J. Engelsen 《Environmental monitoring and assessment》2013,185(8):6343-6352
This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy–energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies. 相似文献
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