Urban growth effects for land use changes leading to natural hazards in parts of Mumbai metro city, India

Guru Balamurugan and Anubhooti

Urbanization and its impact on natural resources, environmental and land use and land cover changes, lead to the occurrence of natural hazards. The study was carried out in one of the rapid urbanization area i.e. in Southeastern parts of Mumbai city (L, ME, MW and N wards), India using Geoinformatics technique. The information was collected from the primary field visit, map was obtained from the local authorities and the SOI toposheets were taken as the base for the urban feature as LULC mapping of the study area. The first hand information about the study area was helpful to map the features of the year 1965 from the SOI toposheet. Further, the remote sensing satellite images like Landsat 5 TM (1992) and IRS P6 LISS IV (2010) satellite images were digitally processed to prepare LULC maps using supervised classification technique. The built-up land, hill and open forest, mangrove and mudflat, mangroves with salt pans, mixed land, open land, salt pans, water body, well are the LULC features classified in the study area. From the LULC maps of the year 1965, 1992 and 2010, the changes during the period of 1965 to 2010 were assessed based on temporal analysis. Further, the LULC maps were analyzed and integrated to obtain the flood and landslide prone zones. The study reveals that the land area which was covered mainly by mud flat and open spaces transformed into built-up area. The built-up area has depicted a positive growth of 14.01% during the period 1965 to 1992, 10.53% during the 1992 to 2010. It is 25.4% less than in comparison to the 1965 to 1992, but the total population has increased from 1946837 in 1992 to 2694131 people in 2010. Due to this the other natural land cover features were much affected leading to the environmental degradation and natural hazard such as landslides and flooding.

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Seismic Design for Floating Column multi- storeyed Building

Chakravarthy P.G. Malavika, Poleswarao K., Balaji K.V.G.D. and Shashidhar K.

Modern multi-storey buildings are constructed with irregularities such as soft storey, vertical or plan irregularity, floating column and heavy loads. It is observed that most of the RC structures with such irregularities constructed in India are highly undesirable in seismically active areas from the results of past earthquake studies. This study explains the seismic analysis of a multi-storey building with floating column constructed in seismically active areas observing its reactions to the external lateral forces exerted on the building in various seismic zones using the software ETABS. Thus highlighting the alternative measures for advancement in the design of the irregular buildings for natural disasters like earthquakes involves in improvising the non-uniform distribution in the buildings such as multi-storey building with floating column. The safer design of such building is recommended in seismically active areas considering the results observed from storey drifts, storey displacements when compared to Response Spectrum method.

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