emi

Figure 1 A section of the Mumbai Development Plans

An important task in developing DRR plans for Greater Mumbai is analysis using geographic information systems.  In order to facilitate GIS analysis geographic data must be readily available and accessible.  Before the collaborative efforts of MCGM and EMI, there were few or no geographic data in the form of shapefiles (a popular geospatial vector data format for geographic information systems software) .  The few that existed were restricted and proper authorization was required to acquire these geographic data.  Eventually, Commissioner Shri. Shantaram Shinde of MCGM granted authorization to EMI to access the more sensitive data, with the full understanding of the security protocols and standard operating procedures.

Figure 2 Topographic Map of Mumbai based on DEM

While waiting for authorization, other geographic data with lesser restrictions were processed and converted to shapefiles.  These include the Mumbai Development Plans, Mumbai ward political boundaries, census data, and topographic data.  With the exception of the Mumbai Development plans, the others are freely available from various sources online.  The Mumbai Development plans are a collection of very large scale land use maps created during 1981 – 2001 in jpeg and pdf formats.  This collection is shared to EMI for georeferencing and digitizing. Professor Gita Kewalramani collected and shared the Development Plans with EMI, along with many other data pertaining to MCGM.

Figure 3 Seismic Risk Assessment of Mumbai by Sinha, et.al.

Some of the online sources include Google Earth, Praja.org, and ASTER GDEM.  Google Earth was primarily used for identification of some of the spots and cross checking of the geographic accuracy of locations.  Praja.org provided census data and a baseline for ward boundaries.  The ward boundaries were later modified after digitizing the development plans, giving the boundaries a more accurate delineation.  ASTER GDEM, a project of METI and NASA, is a repository of free digital elevation models.  EMI downloaded several sections of the free satellite images.  Using geo-processing tools in ArcGIS, the satellite images were mosaicked, (i.e. merged).  From the mosaicked image Greater Mumbai and its environs were clipped and then the contours were extracted.

The seismic risk assessment of Mumbai was developed by Professor Ravi Sinha and his associates Alok Goyal, Rohan Shinde and Mahendra Meena of the Department of Civil Engineering, Indian Institute of Technology – Bombay.  Prof. Sinha’s group provided and shared GIS shapefiles of their seismic study for analysis in the DRR project.

The Flood Preparedness Guidelines (2010) is a “directory of ‘all things relevant for Monsoon preparedness’”, according to the Addl, Municipal Commissioner Manisha Mhaiskar, MCGM.  Included in this directory are maps which are, as of present, being digitized for the location of critical facilities, such as police and fire stations, hospital and emergency shelter facilities, and hazard spots such as flood spots and landslide zones.  This guideline is prepared by MCGM with the inputs of Dr. Madhave Chitale (Fact Finding Committee on Mumbai Floods, 2005), Prof. Kapil Gupta (IIT, Bombay), Prof. Ravi Sinha (IIT, Bombay), S.S.S. Shinde (Joint Municipal Commissioner), S.C. Mohanty (Director and OSD RR, Govt. of Maharashtra), Nandkumar Salvi and Prakash Sanglikar (Ex-Chief Engineers SWD), Dr. Gita Kewalramani (Ex-Prof University of Mumbai), Prof Raju Korti (editor) and Prof Aditee Vaidya (graphic artist).

A large amount of geographic data has already been acquired and processed into shapefiles.  However, much of geographic data remains to be checked for locational accuracy.  Locational accuracy is important for better geographic analysis and in turn, development of a more sound disaster risk reduction plan.