Presenter : DURGASRILAKSHMI HARI
Urban floods typically stem from a complex combination of causes, resulting from a combination of meteorological and hydrological extremes, such as extreme precipitation and flows. However they also frequently occur as a result of human activities. Flash floods occur due to high rate of water flow and poor permeability of the soil. One of the reasons for damage of property and life due to floods is development of unauthorized construction in the drainage channels, river beds etc. which are below high flood level area.
Hyderabad city is one of the fastest growing metropolitan cities with a decadal growth rate of 32% of India located at 17.3700° N, 78.4800°E. Bad urban planning, encroachment of water bodies, Inadequate drainage to carry away the rainwater quickly to streams/rivers, increase in extreme weather events , and lack of preparedness main causes of flooding in Hyderabad. Increased rainfall intensity and urban flooding would become a norm rather than exception unless corrective measures were taken immediately. Flood monitoring is fundamental in these emergency situations, and for planning actions of prevention and adaptation to flooding. The Geographical Information Systems (GIS) help to process Remote Sensing (RS) observations from satellites in a spatial format of maps – both individually and along with tabular data together to provide a new perception – the spatial visualization of information of natural resources. The integration of information derived from RS techniques with other datasets – both in spatial and non-spatial formats provides tremendous potential for identification, monitoring and assessment of floods. This study illustrates how to monitor floods performing the supervised classification of satellite images using QGIS plug-in. This analysis will help us have a better understanding of the floodable areas and therefore provide better flood information support and response to these events which can be useful for several users such as researchers, water managers, decision makers and disaster management authorities for damage assessment and relief management.
Key Words: Geographic Information System (GIS), Remote Sensing (RS), Flood Monitoring.