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The west coast of India is affected by tsunamigenic earthquake along the Makran subduction zone. On 28 November 1945 at 21:56 coordinated universal time (UTC), a massive Makran earthquake (M8.0) generated a destructive tsunami that propagated across the Northern Arabian Sea and the Indian Ocean. This tsunamigenic earthquake was responsible for the loss of life and great destruction along the coasts of India, Pakistan, Iran and Oman. Modelling of tsunami stages has been made for the coasts of Pakistan, Iran, India and Oman using NAMI-DANCE computer code. The fault parameters of the earthquakes for the generation of tsunami are epicentre (25.15° N, 63.48° E), fault area (200 km length and 100 km width), angle of strike, dip and rake (246°, 7° and 90°), focal depth (15 km), slip magnitude (7 m). The bathymetry data are taken from General Bathymetric Chart of the Oceans (GEBCO) and land topography data were collected using Shuttle Radar Topography Mission (SRTM). The present simulation is carried out for a duration of 360 min. It is observed that the maximum calculated tsunami run-ups were about 0.7–1.1 m along the coast of Oman, 0.5 m near Muscat, 0.1 m near Sur, 0.7–1.35 m along the western coast of India, 0.5–2.3 m along the southern coast of Iran and 1.2–5.8 m along the southern coast of Pakistan. After the tsunamigenic earthquake, the tsunami wave reached the Gulf of Kachchh in about 240 min, Okha in about 185 min, Dwarka in about 150 min, Porbandar in about 155 min, Mumbai in about 300 min and Goa in about 210 min. The calculated 2-hr tsunami travel time to the Indian coast is in good agreement with the available reports and published data. If the tsunami strikes during high tide, we should expect more serious hazards which would impact local coastal communities. The results obtained in this study are converted to be compatible with the geographic information system based applications for display and spatial analysis of modelling results. The paper also presents classification of tsunami risk zones based on elevation vulnerability. We expect that the results presented here will be supportive to the tsunami emergency response system and useful in planning the protection measures due to tsunami. [ABSTRACT FROM PUBLISHER]

Wetland acts as a biological supermarket and helps to determine people's lives, livelihoods and needs. In third world countries like India, wetlands are suppressed by over populated surroundings. Although the size, volume and depth of wetlands change due to the whims of the weather, and water pollution and sedimentation are caused by various human activities, people still use wetlands as a means of rice and fish production. This article discusses the continuous decaying of wetlands in the floodplain region of the Bhagirathi–Hooghly river and its impact on human dependency on wetlands. The location of the continuous siltation of the wetlands is known with the help of bathymetry which proves that the wetlands are getting more and more decayed. Agricultural runoff and sewerage from adjacent farmland also continue to pollute the wetlands' environment, with high levels of TDS (total dissolved solids) and Cl2+ (chloride). The result shows that rice and fish production in these decayed wetlands is continuously increasing with seasonal water budget scenario. Comparing economic production with water budgets through SK (seasonal Kendall) test and ARMA (autoregressive moving average process), trend analysis shows the growing demand of the people has made the position of the wetlands miserable, but the economic aspect of the people has benefited. Dredging, public awareness, water pollution prevention and sustainable use of wetlands can be considered as the only way to restore the decayed wetlands to their glory. [ABSTRACT FROM AUTHOR]

The study region located north of Chennai city on the East coast of India is facing shoreline erosion/accretion related problems after the introduction of Ennore Port during 2001. For the present study 25 km of coastal stretch has been taken up, which comprises Ennore port region. natural sandy beaches of Kattupalli Island, which is a turtle breeding ground and Ennore Creek and Pulicat Lake inlets, with a total coastal settlement population of 25,000 people. After the introduction of breakwaters for the port, beach erosion and accretion are considered as critical problems, resulting in damages to the natural set up of the coastal region in the study area. Analyses of coastal dynamics and vulnerable zones of erosion and accretion along the coast were performed during the present study which are highly useful for the development of strategies for heath erosion/accretion management. Four major categories of shoreline changes were observed in the study region, viz., 1) Beach accretion south of Ennore Port, 2) Beach fill erosion north of north breakwater of Ennore Port, 3) Almost stable coastline at the central part of the study region and 4) Shifting inlet of Pulicat Lake. Quantitative analyses are made from shoreline survey using Real Time Kinematic GPS, beach profile survey in four identified transects, characteristics of environmental parameters such as tides, waves, currents and sediment nature in the near shore region. Long shore sediment transport was computed for four cells using numerical modeling package to quantify the changing littoral drift in study region. Results show reduction in sediment transport from -0.66 X 106 m³/year on the southern side of Ennore port to -0.57 x 106 m³/year on the northern side of Ennore Port. [ABSTRACT FROM AUTHOR]