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1.
Vijay K. Agarwal R. Ramani R. M. Patel Meoss Project 《Journal of the Indian Society of Remote Sensing》1987,15(1):55-65
During 1986–1996, several satellite missions on Stereoscopy are planned. This paper sumarises an attempt in evaluating these stereoscopic images for cartographic purposes. For the purpose, we have taken into account a proposed Indian experiment on satellite stereoscopy, which will be based on push-broom type scanning and a ground resolution of 70m×70m. *** DIRECT SUPPORT *** A04KF003 00004 相似文献
2.
We present the first CCD photometric UBVRI observations of the not-so-well-studied open cluster NGC 1624 (OCl 403, Cr 53; α2000 = 04 h 40 m 36 s; δ2000 = + 50˚ 27′ 42″ Trumpler class = I 2 p N). This cluster was observed on 01 February 2004 with the 2 m Himalayan Chandra Telescope at Hanle using a LN2 cooled 2k × 2k CCD. The cluster presents differential reddening with E(B-V) values ranging from 0.70 to 0.90 mag, which could be attributed to the presence of the HII region wherein the cluster is embedded. It is found to be at a distance of 6.025 ± 0.5 kpc and the age of this cluster is estimated to be ∼3.98 × 106 years. In view of these parameters, it can be considered as a young enough cluster located in the direction of the Perseus constellation with the galactic coordinates of l = 155˚.35 and b = + 02 ˚.58. Thus it could also be used as a suitable candidate for tracing the Outer Perseus spiral arm of our Galaxy. The initial mass function slope is derived as 1.65 ± 0.25 by applying the corrections for field star contamination and data incompleteness. This is in good agreement with the Salpeter value within the limits of errors. 相似文献
3.
P. K. Govil J. E. Sorlie D. Sujatha A. K. Krishna N. N. Murthy K. Rama Mohan 《Environmental Earth Sciences》2012,66(1):121-128
Spatial distribution and temporal trends studies were carried out at Katedan Industrial Development Area (KIDA) near Hyderabad,
capital of Andhra Pradesh state, India under Indo-Norwegian Institutional Cooperation Program, to find out the extent of contamination
in streams and lake sediments from the discharge of industrial effluents. Stream and lake sediment samples were collected
from the five lakes in the study area and connecting water streams. The samples were analyzed by XRF spectrometer for toxic
elements. The studies reveal that the stream sediments with in the KIDA and the impounded Noor Mohammed Lake down stream have
high concentration of some of the toxic elements like chromium, nickel, lead, arsenic, zinc etc. The geology of the area indicates
that the study area consists of residual soil of acidic rocks, which are predominantly of Archaean gneisses and granites having
low to medium concentrations of chromium and nickel. The source of these high concentration of elements like lead 2,300 mg/kg,
copper 1,500 mg/kg, arsenic 500 mg/kg, chromium 500 mg/kg etc. cannot be derived from the surrounding acidic rocks and may
be attributed to the industrial effluents released in the ditches and random dumping of hazardous solid waste. It was observed
that the metal concentrations increased in the streams during the dry season (pre-monsoon period). After the monsoon rains,
the metal concentrations in the streams were reduced by half which may be due to dilution. The eroded sediments are deposited
in the lake where very high concentrations were encountered. Overflowing of the lake will spread the contamination further
downstream. The lake sediments will remain as a major source of contamination by desorption to the water phase regardless
of what happens to the effluent discharge in the KIDA. However, some samples showed enrichment of lead, arsenic and nickel
during post-monsoon, which were collected near the dumpsite due to the leaching of toxic elements from the dump site to the
lakes. Some of the toxic elements like nickel and copper have not shown any dilution but have increased after the rains, which
could be due to the leaching of arsenic from the dumpsite to the lake along with rainwater. Geochemical maps showing the distribution
of heavy/trace elements in streams and lakes are prepared and presented in this paper. Effect of toxic elements on the health
of the residents in the surrounding residential areas is also discussed. 相似文献
4.
This paper deals with the landslide susceptibility zonation of Tevankarai Ar sub-watershed using weighted similar choice fuzzy
method in a GIS environment. There has been a rapid increase in landslide occurrences in the Kodaikkanal town and area surrounding
the town specially in the settlements around the town and road links leading to and from the town. This necessitates a detailed
study of slope instability problems in this area. It is observed that these incidences occur frequently during the monsoon
and summer showers. Rainfall is identified as the prime triggering factor. Eleven physical factors that cause instability
are identified as causative factors from the field investigations and landslide occurrences. Land use pattern, slope gradient,
curvature and aspect, weathering index which are evaluated from the weathering ratios of different chemical constituents of
the three major lithological variations, soil type, hydraulic conductivity of soil and soil thickness, geomorphology, drainage,
and lineament have been utilized to prepare the spatial variation. A weighted similar choice fuzzy model which ranks a set
of alternatives by identifying the similarity between the outcome of alternatives and outcome of ideal alternatives is used
to rank the causative factors. Each causative factor is classified into sub-categories and rated based on their effect on
stimulating the landslide event using qualitative judgment derived from field studies and landslide history. The prepared
thematic maps of causative factors are integrated, utilizing the GIS software Arcmap. The outcome has projected the low, moderate,
high, and very high landslide susceptibility zones. The high-hazard and very high-hazard areas fall in the northwestern part
characterized by croplands and agricultural plantations, while the moderate hazard zones are seen in prominent settlements
and low-hazard zones are observed in the sparse settlements and zones of less agricultural activity. The model is verified
using the relative landslide density (R) index, and the susceptibility map is found to be consistent with the mapped landslide
incidences. The results from this study illustrate that the use of weighted similar choice fuzzy method is suitable for landslide
susceptibility mapping on regional scale in growing hill towns as Kodaikkanal town. 相似文献
5.
GIS based landslide susceptibility mapping of Tevankarai Ar sub-watershed, Kodaikkanal, India using binary logistic regression analysis 总被引：5，自引：0，他引：5
Landslide susceptibility mapping is the first step in regional hazard management as it helps to understand the spatial distribution of the probability of slope failure in an area.An attempt is made to map the landslide susceptibility in Tevankarai Ar subwatershed,Kodaikkanal,India using binary logistic regression analysis.Geographic Information System is used to prepare the database of the predictor variables and landslide inventory map,which is used to build the spatial model of landslide susceptibility.The model describes the relationship between the dependent variable(presence and absence of landslide) and the independent variables selected for study(predictor variables) by the best fitting function.A forward stepwise logistic regression model using maximum likelihood estimation is used in the regression analysis.An inventory of 84 landslides and cells within a buffer distance of 10m around the landslide is used as the dependent variable.Relief,slope,aspect,plan curvature,profile curvature,land use,soil,topographic wetness index,proximity to roads and proximity to lineaments are taken as independent variables.The constant and the coefficient of the predictor variable retained by the regression model are used to calculate the probability of slope failure and analyze the effect of each predictor variable on landslide occurrence in thestudy area.The model shows that the most significant parameter contributing to landslides is slope.The other significant parameters are profile curvature,soil,road,wetness index and relief.The predictive logistic regression model is validated using temporal validation data-set of known landslide locations and shows an accuracy of 85.29 %. 相似文献
6.
Naduvilaveettil Sukumaran Kalesh Chenycherri House Sujatha S. Muraleedharan Nair 《Journal of Oceanography》2001,57(1):29-36
Information on the distribution of dissolved Folin phenol active substances (FPAS) such as tannin and lignin in the seawater along the west coast of India is provided. Notable amounts of FPAS (surface concentrations: 80 g/l to 147 g/l and bottom concentrations: 80 g/l to 116 g/l) were detected in the seawater along the coast. The distribution pattern brings about a general depth-wise decrease. A seaward decrease was observed in the southern stations whereas reverse was the case in northern stations. A significant negative correlation was observed between FPAS concentration and dissolved oxygen in sub-surface samples. The appreciable amounts of FPAS detected in the coastal waters indicate the presence of organic matter principally originating from terrestrial (upland and coastal marsh) ecosystems in the marine environment. In this context, they may be used as tracers to determine the fate of coastalborn dissolved organic matter in the ocean and to determine directly the relationship between allochthonous and autochthonous organic matter. 相似文献
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Water, soil, suspended load and biomass samples were collected from a sewage and sludge treated lake (Lake Dalavayi) around Mysore, Karnataka, India. The polluted lake water is mainly used for irrigation and domestic purposes. The samples have been analysed for heavy metals (Cu, Cr, Co, Cd, Ni, Fe, Mn, V, Zn, Sr) and cations (Ca, Na, Mg) by Inductively Coupled Plasma Emission Spectrometer (ICP) model Labtam 8500. With the exception of water, all the matrices suspended particulate matter, lake bed sediment and biomass of the lake show high concentrations of heavy metals and cations when compared to the World Health Organization (WHO) standard, indicating metal toxicity in this lake. Additional inputs of soaps and detergents carried by sewage water are causing the eutrophication of the lake. Elevated levels of heavy metal toxicity, especially Co and Cd, are indicated by the bioindicator Eichornia cressepes (water hyacinth), which, using these metals as micronutrients, has grown luxuriously over the lake water, further augmenting the death of lifeforms in the lake. 相似文献
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