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Assessment of water quality parameters of the Harike wetland in India, a Ramsar site, using IRS LISS IV satellite data 总被引:1,自引:0,他引:1
Samson Okongo Mabwoga Amit Chawla Ashwani Kumar Thukral 《Environmental monitoring and assessment》2010,170(1-4):117-128
This study aims at the classification and water quality assessment of Harike wetland (Ramsar site) in India using satellite images from the Indian Remote Sensing satellite, Resourcesat (IRS P6). The Harike wetland is a converging zone of two rivers, Beas and Sutlej. The satellite images of IRS Linear Imaging Self Scanner (LISS) IV multispectral sensor with three bands (green, red, and near infrared (NIR)) and a spatial resolution of 5.8 m were classified using supervised image classification techniques. Field points for image classification and water sampling were recorded using a Garmin eTrex Global Positioning System. The water quality parameters assessed were dissolved oxygen, conductivity, pH, turbidity, total and suspended solids (SS), chemical oxygen demand, and Secchi disk transparency (SDT). Correlations were established between turbidity and SS, SS and SDT, and total solids and turbidity. Using reflectance values from the green, red, and NIR bands, we then plotted the water quality parameters with the mean digital number values from the satellite imagery. The NIR band correlated significantly with the water quality parameters, whereas, using SDT values, it was observed that the green and the red reflectance bands were able to distinguish the waters from the two rivers, which have different water qualities. 相似文献
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This paper sheds light on changing farmers' land management practices in two mountain watersheds, with and without external
assistance, in the western hills of Nepal. Information used in the analysis were obtained through a survey of 300 households,
group discussion, key informant interviews, and field observation conducted during April–September 1999. Confronted with ever-decreasing
landholding size due to a steadily growing population and scarcity of nonfarming employment opportunities, farmers in both
watersheds have increasingly adopted assorted types of structural and biological measures to control soil erosion, landslides,
gully expansion, and soil nutrient loss to maintain or even enhance land productivity. Adoption of gully control measures,
construction of the retention walls, alley cropping, use of vegetative measures for landslide control, mulching, and use of
green manure and chemical fertilizers are found significantly high in the project area due to the provision of technical and
financial support, whereas composting is found significantly high in the nonproject area. Different from the traditionally
held beliefs, population pressure on a finite land resource has brought positive change in land management. However, the experience
from both watersheds indicates that there is limit to the extent that resource poor farmers can respond to land degradation
without any external assistance. Required is the arrangement for appropriate polices and support services and facilities enabling
farmers to adopt locationally suitable and economically attractive land management technologies. 相似文献
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SINGH R KUMAR V SHARMA S BEHL RK SINGH BP NARULA N 《应用与环境生物学报》2005,11(6):751-755
ThepracticaluseofAzotobacterchroococcumasbiofertilizer hasbeenincreasinglyidentifiedinrecentyears.Oftentheefficacy ofthesebacteriaisassessedonthebasisofcropresponseswithout knowingthesurvival,persistenceandcompetitiveabilityofthein troducedstrain.Inoculat… 相似文献
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Madhumita Das Ashwani Kumar 《Environmental science and pollution research international》2009,16(4):466-473
Background, aim, and scope
High-quality waters are steadily retreating worldwide. Discharge of industrial effluent in the environment again declines soil/water quality to a great extent. On the other hand, effluent reuse in agriculture could be a means to conserve natural resources by providing assured water supply for growing crops. But industrial effluents are highly variable in nature, containing a variety of substances, and all are not favorable for farming. Appraisal and developing modes of effluent reuse is therefore a prerequisite to enable its proper use in agriculture. Effluents of various industries were assessed and approaches for their use in farming were developed for a particular region in this study. As per availability of effluents, the same could be implemented in other water-scarce areas. 相似文献6.
SINGH Shuchi SOOD Anchal SHARMA Shivesh KUMAR Vivek SINGH Kamal Deep PANDEY Piyush 《应用与环境生物学报》2007,13(3):357-360
The rhizospheres of established tea bushes have some specificcharacteristics which are associated with the long lived nature of teaplants,viz.,negative rhizospheric effect,lowering of soil pH,antagonistic activities among microbial communities and dominan… 相似文献
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Truck and bus frontal impacts account for a major proportion of pedestrian fatalities in many less motorized countries. To understand this phenomenon, we have collected injury data on pedestrian impacts with buses and trucks and performed computer simulations to identify critical design parameters at 15–45 km/h impact velocities for further investigation. A male dummy which was scaled to fifty percentile Indian dimensions has been used for simulations using MADYMO. Bumper height, bumper offset and grille inclination affect the pelvis and thorax forces and Head Injury Criterion values critically. Bumper width has less effect. Simulations were performed to optimize for the above–mentioned three parameters. Changes in front geometric parameters reduce injury to the upper body and head below safety limits for the existing force–displacement properties but do not affect leg injuries significantly. Hence bumpers need to be made less stiff. Injury data shows that pedestrians also sustain tibia fractures in bus/truck impacts in apparent low velocity impacts. The computer modeling does not offer adequate explanation for this phenomenon. These simulations confirm that it is theoretically possible to make truck/bus fronts safer for pedestrians in impacts up to 35 km/h. 相似文献
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A bacterial consortium was developed by continuous enrichment of microbial population isolated from sediment core of pulp andpaper mill e uent in mineral salts medium (MSM) supplemented with pentachlorophenol (PCP) as sole source of carbon and energy inthe chemostat. The consortia contained three bacterial strains. They were identified as Escherichia coli, Pseudomonas aeruginosa andAcinetobacter sp. by 16S rRNA gene sequence analysis. Acinetobacter sp. readily degraded PCP through the formation of tetrachloro-phydroquinone(TecH), 2-chloro-1,4-benzenediol and products of ortho ring cleavage detected by gas chromatograph/mass spectrometer(GC-MS). Out of the three acclimated PCP degrading bacterial strains only one strain, Acinetobacter sp. showed the presence ofintegron gene cassette as a marker of its stability and antibiotic resistance. The strain possessed a 4.17 kb amplicon with 22 ORF’s. Theplasmid isolated from the Acinetobacter sp. was subjected to shotgun cloning through restriction digestion by BamHI, HindIII and SalI,ligated to pUC19 vector and transformed into E. coli XLBlue1 , and finally selected on MSM containing PCP as sole source of carbonand energy with ampicillin as antibiotic marker. DNA sequence analysis of recombinant clones indicated homology with integron genecassette and multiple antibiotic resistance genes. 相似文献
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Habitat fragmentation affects species distribution and abundance, and drives extinctions. Escalated tropical deforestation and fragmentation have confined many species populations to habitat remnants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecological, anthropogenic, and species‐related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information‐theoretic framework, the effect of local‐ and landscape‐scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump‐tailed (Macaca arctoides) and northern pig‐tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage. Correlaciones Locales y de Paisaje de la Distribución y Persistencia de Primates en los Bosques Lluviosos Remanentes en el Valle del Alto Brahmaputra, Noreste de India 相似文献
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The effect of 24-epibrassinolide seed soaking on imidacloprid residues in green pods and mature seeds of Brassica juncea L. plants was investigated. The activities of the antioxidative enzymes glutathione-S-transferase, glutathione peroxidase, glutathione reductase, ascorbate peroxidase and guaiacol peroxidase, and the content of glutathione were determined. Imidacloprid residues in green pods were analyzed and quantified by gas chromatography-mass spectrometry, revealing that 24-epibrassinolide treatment resulted in a decrease of residues by almost 30%. In mature seeds, no pesticide residues were detected. Activities of all the antioxidative enzymes and glutathione content were found to be high in plants grown in soil amended with 300 mg imidacloprid kg?1 soil, but pre-soaking with 100 nmol L?1 24-epibrassinolide further enhanced the activities of all these enzymes and the glutathione content. 相似文献