15 research outputs found

    Coastal Sediment Dynamics Around Netravati – Gurpur River Mouth Through Integrated Approach

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

    Land use/Land cover changes around Rameshwaram Island, east coast of India

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    1183-1186Land-use/land cover changes are studied using the Indian Remote Sensing satellite (IRS-1C, IRS-P6) Linear Image Self-scan Sensor (LISS) III data of 1998 and 2010. Coastal land use categories such as sand, vegetation, coral reef and water have been identified using interpretation keys. Results of land-use/land cover assessment based on visual interpretation are presented. The study indicates water body of 178 and 177 km2, sand features of 32 and 32 km2, vegetation of 28 and 35 km2 and coral reef of 5 and 6 km2 respectively.</span

    Hydraulic Performance of Pervious Concrete Based on Small Size Aggregates

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    The paper aims to study the impact of clogging on pervious concrete mixes and explore a simple method to calculate permeability and clogging using the falling head method in a fabricated unit. The materials used are cementitious materials and aggregates, along with superplasticizers. The cementitious materials used are OPC Grade 53 cement and micro Ground Granulated Blast Furnace Slag (μGGBS). Two separate narrow aggregate gradations are used: 2.36–4.75 mm and 4.75–6.30 mm. The water-binder ratio is taken as 0.25, and the aggregate-binder ratio is taken as 3.33. The compressive strength, permeability, and clogging potential of pervious concrete are calculated. The average permeability for 2.36–4.75 mm and 4.75–6.3 mm is 4.78 mm/s and 8.16 m/s, respectively. The clogging materials used are clay and sand with a concentration of 5 g/l. The introduction of clay slurry reduces the permeability by 69.8% and 74.9%, respectively, and with sand, it decreases by 74.7% and 71.7%, respectively, in its first cycle. The permeability response for such small aggregates is different from the standard coarse aggregates. The paper compares the study’s compressive strength, porosity, and permeability with the existing literature. It concludes that the maximum clogging occurs when the clogging material is introduced to the specimen for the first time. The degradation of permeability depends on the clogging particle’s particulate size and the concrete matrix’s pore size. The smaller aggregates in pervious concrete are not recommended in areas of high siltation

    A Comparative Analysis of Histogram Equalization based Techniques for Contrast Enhancement and Brightness Preserving

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    Histogram Equalization (HE) is a simple and effective image enhancement technique.But, it tends to change the mean brightness of the image to the middle level of the permitted range, and hence is not a very suitable for consumer product. While preserving the original brightness is essential to avoid annoying artefacts. To preserve brightness and to enhance contrast of images, numerous methods are introduced, but many of them present unwanted artefacts such as intensity saturation, over-enhancement and noise amplification. In the present paper, available histogram equalization based methods are reviewed and compared with image quality measurement (IQM)tools such as Absolute Mean Brightness Error (AMBE) to assess brightness preserving and Peak Signal-to-Noise Ratio (PSNR) to evaluate contrast enhancement

    Analysis of IRS-P4 OCM data for estimating the suspended sediment concentrations along the Mangalore Coast, India

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    Information on Suspended Sediment Concentration (SSC) in coastal waters is necessary for the understanding and management of the coastal environment. In the present study, estimation of SSC has been carried out along the Mangalore Coast, West coast of India, using both in-situ and Indian Remote sensing Satellite (IRS) – P4 Ocean Color Monitor (OCM) data. The OCM Data Analysis Software (OCMDAS) developed by Space Applications Centre (SAC), Ahmedabad, India, which is based Tassan’s algorithm was used to estimate the SSC and validated through sea-truth data collected along the Mangalore Coast. Eighty six surface water samples were collected during the post-monsoon (21.11.1999) and pre-monsoon (07.05.2000) period, near synchronized with IRS-P4-satellite overpass, and SSC was measured using 0.47µm Whatman filter papers with the help of Millipore filter assembly. Out of ninety water samples, eighty two were used to generate the SSC map of the study area and eight samples at few important locations (rivermouth with/without breakwater, man-made coastal structures, and open beaches) were selected to validate the algorithm. Measured SSC varied between 26mg/L and 48mg/L in pre-monsoon and between 16mg/L and 40mg/L during post-monsoon period. The estimated SSC varied between 11mg/L and 47mg/L in pre-monsoon and between 14mg/L and 33mg/L during post-monsoon period. The co-efficient of determination for the relationship developed between measured and estimated SSC is about 0.90 and root mean square error is 14 mg/L
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